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Describe the package management #15
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@ferventcoder I would like to ask for your help here. As you maintain the NuGet packages, and as we are considering getting away from mingw-get, would you please detail what we would need to do in order to switch to chocolatey/NuGet? |
Hi @dscho - Is this for the consumer end of Git for Windows or mSysGit? |
@ferventcoder primarily for the end user (but remember, we need a shell and Perl with Subversion bindings, so we probably need to ship a minimal MSys). As for msysGit: we are switching to the SDK (have a look at the org in which this ticket lives). |
@dscho As an aside - I personally love all of the tools provided in the bin folder with Git for Windows. For the end user on Chocolatey's end, right now the state of the world is that there is a handoff - the installer is created (by your team) and the Chocolatey package (git.install) knows how to download the installer and install/upgrade Git silently. From my perspective, that is it. If there was/is a way to use mingw-get from within git, I've never used it (or at least realized I was using if it is used by git under the covers). There is also the portable version, which the Chocolatey package (git.commandline) knows how to download and put on the PATH.
Are these the details you are looking for or more of an internal switch? |
Well, the discussion revolves around the problem that Git users currently need to use a full-blown installer to upgrade Git to a new version, and if they only need, say, an upgrade of bash, they still need a complete new version of the Git installer that only upgrades the bash. So we're looking for ways to make this more efficient, in particular from a maintenance and contribution point of view. |
Ah, I see. So you are looking to use more of the Chocolatey ecosystem versus adding everything and the kitchen sink to the installer. |
I think for that, you can start to split things out and depend on git subpackages, that way you can update those out of band. Like |
@ferventcoder okay, so basically the NuGet ecosystem does not provide the packages that we would require yet... not sure we have the manpower to conjure those packages into existence. |
What I envision is a traditional route of installation, where a user can download an AIO (all in one) package (the current) and install it. And then you provide all of the subpackages that go into that AIO so each can be upgraded separately. Those would work with the current install location of git on the user system (which can be found by the registry install location). This also allows for when the next tool has a CVE, you can be much quicker to patch just that tool. Perhaps ultimately move away from the AIO and just provide the smaller packages, providing instructions on how to install all of them (or to use Chocolatey) - the side effect of this is that outside of Chocolatey it complicates the user experience. |
Again... I was looking for a way to reduce the maintenance burden, not to increase it 😄 |
Correct. Right now, I'm not sure if the ecosystem is at that level, yet.
:) One thing to consider is that mingw-get will likely become part of what chocolatey can intuitively install from as well. All of the alternative sources (cygwin, python, gems, etc) will likely get better in the next incarnation of Chocolatey (which I'm just about to add back in the alternative sources for) so that they do a better job of installing the alternative pkg mgr, then installing packages from (which is currently user driven, not specified from packages themselves). Then we'll likely enhance the nuspec that describes the package and the dependencies to allow for taking dependencies on these alternative sources, thus <dependencies>
<dependency id="bash" source="mingw" />
<depencency id="less" source="cygwin" />
</dependencies> |
That is probably about six months out at the moment. |
Okay. So we're stuck with |
That doesn't sound good. MingW to me is better than CygWin, I'd rather see it survive over anything else for Linux tools coming to Windows. :/ |
Okay, I got around to try and use MSys2 and Pacman, and updated the Wiki accordingly. |
virtualfilesystem: don't run the virtual file system hook if the index has been redirected
Add virtual file system settings and hook proc. On index load, clear/set the skip worktree bits based on the virtual file system data. Use virtual file system data to update skip-worktree bit in unpack-trees. Use virtual file system data to exclude files and folders not explicitly requested. The hook was first contributed in private, but was extended via the following pull requests: git-for-windows#15 git-for-windows#27 git-for-windows#33 git-for-windows#70 Signed-off-by: Ben Peart <Ben.Peart@microsoft.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Most of these pointers can safely be freed when cmd_clone() completes, therefore we make sure to free them. The one exception is that we have to UNLEAK(repo) because it can point either to argv[0], or a malloc'd string returned by absolute_pathdup(). We also have to free(path) in the middle of cmd_clone(): later during cmd_clone(), path is unconditionally overwritten with a different path, triggering a leak. Freeing the first path immediately after use (but only in the case where it contains data) seems like the cleanest solution, as opposed to freeing it unconditionally before path is reused for another path. This leak appears to have been introduced in: f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17) These leaks were found when running t0001 with LSAN, see also an excerpt of the LSAN output below (the full list is omitted because it's far too long, and mostly consists of indirect leakage of members of the refs we are freeing). Direct leak of 178 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10 #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21 #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 vv #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8 #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20 #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9 #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8 #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8 #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4 #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9 #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4 #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9 #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 178 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10 #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8 #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20 #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9 #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8 #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8 #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4 #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9 #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4 #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9 #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 105 byte(s) in 1 object(s) allocated from: #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8 #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2 #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3 #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4 #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2 #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10 #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The primary goal of this change is to stop leaking init_db_template_dir. This leak can happen because: 1. git_init_db_config() allocates new memory into init_db_template_dir without first freeing the existing value. 2. init_db_template_dir might already contain data, either because: 2.1 git_config() can be invoked twice with this callback in a single process - at least 2 allocations are likely. 2.2 A single git_config() allocation can invoke the callback multiple times for a given key (see further explanation in the function docs) - each of those calls will trigger another leak. The simplest fix for the leak would be to free(init_db_template_dir) before overwriting it. Instead we choose to convert to fetching init.templatedir via git_config_get_value() as that is more explicit, more efficient, and avoids allocations (the returned result is owned by the config cache, so we aren't responsible for freeing it). If we remove init_db_template_dir, git_init_db_config() ends up being responsible only for forwarding core.* config values to platform_core_config(). However platform_core_config() already ignores non-core.* config values, so we can safely remove git_init_db_config() and invoke git_config() directly with platform_core_config() as the callback. The platform_core_config forwarding was originally added in: 2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11 And I suspect the potential for a leak existed since the original implementation of git_init_db_config in: 90b4518 (Add `init.templatedir` configuration variable., 2010-02-17) LSAN output from t0001: Direct leak of 73 byte(s) in 1 object(s) allocated from: #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8 #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2 #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2 #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2 #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2 #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10 #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11 #8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7 #9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2 #10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2 #11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2 #12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11 #13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9 #14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of these pointers can safely be freed when cmd_clone() completes, therefore we make sure to free them. The one exception is that we have to UNLEAK(repo) because it can point either to argv[0], or a malloc'd string returned by absolute_pathdup(). We also have to free(path) in the middle of cmd_clone(): later during cmd_clone(), path is unconditionally overwritten with a different path, triggering a leak. Freeing the first path immediately after use (but only in the case where it contains data) seems like the cleanest solution, as opposed to freeing it unconditionally before path is reused for another path. This leak appears to have been introduced in: f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17) These leaks were found when running t0001 with LSAN, see also an excerpt of the LSAN output below (the full list is omitted because it's far too long, and mostly consists of indirect leakage of members of the refs we are freeing). Direct leak of 178 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10 #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21 #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 178 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10 #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8 #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20 #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9 #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8 #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8 #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4 #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9 #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4 #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9 #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 105 byte(s) in 1 object(s) allocated from: #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8 #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2 #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3 #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4 #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2 #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10 #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The primary goal of this change is to stop leaking init_db_template_dir. This leak can happen because: 1. git_init_db_config() allocates new memory into init_db_template_dir without first freeing the existing value. 2. init_db_template_dir might already contain data, either because: 2.1 git_config() can be invoked twice with this callback in a single process - at least 2 allocations are likely. 2.2 A single git_config() allocation can invoke the callback multiple times for a given key (see further explanation in the function docs) - each of those calls will trigger another leak. The simplest fix for the leak would be to free(init_db_template_dir) before overwriting it. Instead we choose to convert to fetching init.templatedir via git_config_get_value() as that is more explicit, more efficient, and avoids allocations (the returned result is owned by the config cache, so we aren't responsible for freeing it). If we remove init_db_template_dir, git_init_db_config() ends up being responsible only for forwarding core.* config values to platform_core_config(). However platform_core_config() already ignores non-core.* config values, so we can safely remove git_init_db_config() and invoke git_config() directly with platform_core_config() as the callback. The platform_core_config forwarding was originally added in: 2878533 (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11 And I suspect the potential for a leak existed since the original implementation of git_init_db_config in: 90b4518 (Add `init.templatedir` configuration variable., 2010-02-17) LSAN output from t0001: Direct leak of 73 byte(s) in 1 object(s) allocated from: #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8 #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2 #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2 #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2 #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2 #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10 #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11 #8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7 #9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2 #10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2 #11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2 #12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11 #13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9 #14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
transport_get_remote_refs() can populate the transport struct's remote_refs. transport_disconnect() is already responsible for most of transport's cleanup - therefore we also take care of freeing remote_refs there. There are 2 locations where transport_disconnect() is called before we're done using the returned remote_refs. This patch changes those callsites to only call transport_disconnect() after the returned refs are no longer being used - which is necessary to safely be able to free remote_refs during transport_disconnect(). This commit fixes the following leak which was found while running t0000, but is expected to also fix the same pattern of leak in all locations that use transport_get_remote_refs(): Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8 #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20 #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9 #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8 #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8 #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4 #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9 #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4 #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9 #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
…sponse query_result can be be an empty strbuf (STRBUF_INIT) - in that case trying to read 3 bytes triggers a buffer overflow read (as query_result.buf = '\0'). Therefore we need to check query_result's length before trying to read 3 bytes. This overflow was introduced in: 940b94f (fsmonitor: log invocation of FSMonitor hook to trace2, 2021-02-03) It was found when running the test-suite against ASAN, and can be most easily reproduced with the following command: make GIT_TEST_OPTS="-v" DEFAULT_TEST_TARGET="t7519-status-fsmonitor.sh" \ SANITIZE=address DEVELOPER=1 test ==2235==ERROR: AddressSanitizer: global-buffer-overflow on address 0x0000019e6e5e at pc 0x00000043745c bp 0x7fffd382c520 sp 0x7fffd382bcc8 READ of size 3 at 0x0000019e6e5e thread T0 #0 0x43745b in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7 #1 0x43786d in bcmp /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:887:10 #2 0x80b146 in fsmonitor_is_trivial_response /home/ahunt/oss-fuzz/git/fsmonitor.c:192:10 #3 0x80b146 in query_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:175:7 #4 0x80a749 in refresh_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:267:21 #5 0x80bad1 in tweak_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:429:4 #6 0x90f040 in read_index_from /home/ahunt/oss-fuzz/git/read-cache.c:2321:3 #7 0x8e5d08 in repo_read_index_preload /home/ahunt/oss-fuzz/git/preload-index.c:164:15 #8 0x52dd45 in prepare_index /home/ahunt/oss-fuzz/git/builtin/commit.c:363:6 #9 0x52a188 in cmd_commit /home/ahunt/oss-fuzz/git/builtin/commit.c:1588:15 #10 0x4ce77e in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #11 0x4ccb18 in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #12 0x4cb01c in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #13 0x4cb01c in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #14 0x6aca8d in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #15 0x7fb027bf5349 in __libc_start_main (/lib64/libc.so.6+0x24349) #16 0x4206b9 in _start /home/abuild/rpmbuild/BUILD/glibc-2.26/csu/../sysdeps/x86_64/start.S:120 0x0000019e6e5e is located 2 bytes to the left of global variable 'strbuf_slopbuf' defined in 'strbuf.c:51:6' (0x19e6e60) of size 1 'strbuf_slopbuf' is ascii string '' 0x0000019e6e5e is located 126 bytes to the right of global variable 'signals' defined in 'sigchain.c:11:31' (0x19e6be0) of size 512 SUMMARY: AddressSanitizer: global-buffer-overflow /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7 in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) Shadow bytes around the buggy address: 0x000080334d70: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 0x000080334d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080334d90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080334da0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080334db0: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9 =>0x000080334dc0: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9[f9]01 f9 f9 f9 0x000080334dd0: f9 f9 f9 f9 03 f9 f9 f9 f9 f9 f9 f9 02 f9 f9 f9 0x000080334de0: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 0x000080334df0: f9 f9 f9 f9 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 0x000080334e00: f9 f9 f9 f9 00 00 00 00 f9 f9 f9 f9 01 f9 f9 f9 0x000080334e10: f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb Shadow gap: cc Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Acked-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
transport_get_remote_refs() can populate the transport struct's remote_refs. transport_disconnect() is already responsible for most of transport's cleanup - therefore we also take care of freeing remote_refs there. There are 2 locations where transport_disconnect() is called before we're done using the returned remote_refs. This patch changes those callsites to only call transport_disconnect() after the returned refs are no longer being used - which is necessary to safely be able to free remote_refs during transport_disconnect(). This commit fixes the following leak which was found while running t0000, but is expected to also fix the same pattern of leak in all locations that use transport_get_remote_refs(): Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8 #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20 #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9 #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8 #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8 #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4 #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9 #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4 #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9 #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
rev.prune_data is populated (in multiple functions) via copy_pathspec, and therefore needs to be cleared after running the diff in those functions. rev(_info).pending is populated indirectly via setup_revisions, and also needs to be cleared once diffing is done. These leaks were found while running t0008 or t0021. The rev.prune_data leaks are small (80B) but noisy, hence I won't bother including their logs - the rev.pending leaks are bigger, and can happen early in the course of other commands, and therefore possibly more valuable to fix - see example log from a rebase below: Direct leak of 2048 byte(s) in 1 object(s) allocated from: #0 0x49ab79 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x9ac2a6 in xrealloc wrapper.c:126:8 #2 0x83da03 in add_object_array_with_path object.c:337:3 #3 0x8f5d8a in add_pending_object_with_path revision.c:329:2 #4 0x8ea50b in add_pending_object_with_mode revision.c:336:2 #5 0x8ea4fd in add_pending_object revision.c:342:2 #6 0x8ea610 in add_head_to_pending revision.c:354:2 #7 0x9b55f5 in has_uncommitted_changes wt-status.c:2474:2 #8 0x9b58c4 in require_clean_work_tree wt-status.c:2553:6 #9 0x606bcc in cmd_rebase builtin/rebase.c:1970:6 #10 0x4cd91d in run_builtin git.c:467:11 #11 0x4cb5f3 in handle_builtin git.c:719:3 #12 0x4ccf47 in run_argv git.c:808:4 #13 0x4caf49 in cmd_main git.c:939:19 #14 0x69dc0e in main common-main.c:52:11 #15 0x7f2d18909349 in __libc_start_main (/lib64/libc.so.6+0x24349) Indirect leak of 5 byte(s) in 1 object(s) allocated from: #0 0x486834 in strdup ../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3 #1 0x9ac048 in xstrdup wrapper.c:29:14 #2 0x83da8d in add_object_array_with_path object.c:349:17 #3 0x8f5d8a in add_pending_object_with_path revision.c:329:2 #4 0x8ea50b in add_pending_object_with_mode revision.c:336:2 #5 0x8ea4fd in add_pending_object revision.c:342:2 #6 0x8ea610 in add_head_to_pending revision.c:354:2 #7 0x9b55f5 in has_uncommitted_changes wt-status.c:2474:2 #8 0x9b58c4 in require_clean_work_tree wt-status.c:2553:6 #9 0x606bcc in cmd_rebase builtin/rebase.c:1970:6 #10 0x4cd91d in run_builtin git.c:467:11 #11 0x4cb5f3 in handle_builtin git.c:719:3 #12 0x4ccf47 in run_argv git.c:808:4 #13 0x4caf49 in cmd_main git.c:939:19 #14 0x69dc0e in main common-main.c:52:11 #15 0x7f2d18909349 in __libc_start_main (/lib64/libc.so.6+0x24349) SUMMARY: AddressSanitizer: 2053 byte(s) leaked in 2 allocation(s). Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
real_ref was previously populated by dwim_ref(), which allocates new memory. We need to make sure to free real_ref when discarding it. (real_ref is already being freed at the end of create_branch() - but if we discard it early then it will leak.) This fixes the following leak found while running t0002-t0099: Direct leak of 5 byte(s) in 1 object(s) allocated from: #0 0x486954 in strdup /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3 #1 0xdd6484 in xstrdup wrapper.c:29:14 #2 0xc0f658 in expand_ref refs.c:671:12 #3 0xc0ecf1 in repo_dwim_ref refs.c:644:22 #4 0x8b1184 in dwim_ref ./refs.h:162:9 #5 0x8b0b02 in create_branch branch.c:284:10 #6 0x550cbb in update_refs_for_switch builtin/checkout.c:1046:4 #7 0x54e275 in switch_branches builtin/checkout.c:1274:2 #8 0x548828 in checkout_branch builtin/checkout.c:1668:9 #9 0x541306 in checkout_main builtin/checkout.c:2025:9 #10 0x5395fa in cmd_checkout builtin/checkout.c:2077:8 #11 0x4d02a8 in run_builtin git.c:467:11 #12 0x4cbfe9 in handle_builtin git.c:719:3 #13 0x4cf04f in run_argv git.c:808:4 #14 0x4cb85a in cmd_main git.c:939:19 #15 0x820cf6 in main common-main.c:52:11 #16 0x7f30bd9dd349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a sparse index it is possible for the tree that is being verified to be freed while it is being verified. This happens when index_name_pos() looks up a entry that is missing from the index and that would be a descendant of a sparse entry. That triggers a call to ensure_full_index() which frees the cache tree that is being verified. Carrying on trying to verify the tree after this results in a use-after-free bug. Instead restart the verification if a sparse index is converted to a full index. This bug is triggered by a call to reset_head() in "git rebase --apply". Thanks to René Scharfe for his help analyzing the problem. ==74345==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000001b20 at pc 0x557cbe82d3a2 bp 0x7ffdfee08090 sp 0x7ffdfee08080 READ of size 4 at 0x606000001b20 thread T0 #0 0x557cbe82d3a1 in verify_one /home/phil/src/git/cache-tree.c:863 #1 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #2 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #3 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #4 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910 #5 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250 #6 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87 #7 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 #8 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 #9 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 #10 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 #11 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 #12 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 #13 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) #14 0x557cbe5bcb8d in _start (/home/phil/src/git/git+0x1b9b8d) 0x606000001b20 is located 0 bytes inside of 56-byte region [0x606000001b20,0x606000001b58) freed by thread T0 here: #0 0x7fdd4bacff19 in __interceptor_free /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:127 #1 0x557cbe82af60 in cache_tree_free /home/phil/src/git/cache-tree.c:35 #2 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #3 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #4 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #5 0x557cbeb2557a in ensure_full_index /home/phil/src/git/sparse-index.c:310 #6 0x557cbea45c4a in index_name_stage_pos /home/phil/src/git/read-cache.c:588 #7 0x557cbe82ce37 in verify_one /home/phil/src/git/cache-tree.c:850 #8 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #9 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #10 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #11 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910 #12 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250 #13 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87 #14 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 #15 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 #16 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 #17 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 #18 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 #19 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 #20 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) previously allocated by thread T0 here: #0 0x7fdd4bad0459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x557cbebc1807 in xcalloc /home/phil/src/git/wrapper.c:140 #2 0x557cbe82b7d8 in cache_tree /home/phil/src/git/cache-tree.c:17 #3 0x557cbe82b7d8 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:763 #4 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764 #5 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764 #6 0x557cbe8304e1 in prime_cache_tree /home/phil/src/git/cache-tree.c:779 #7 0x557cbeab7fa7 in reset_head /home/phil/src/git/reset.c:85 #8 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 #9 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 #10 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 #11 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 #12 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 #13 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 #14 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a sparse index it is possible for the tree that is being verified to be freed while it is being verified. This happens when the index is sparse but the cache tree is not and index_name_pos() looks up a path from the cache tree that is a descendant of a sparse index entry. That triggers a call to ensure_full_index() which frees the cache tree that is being verified. Carrying on trying to verify the tree after this results in a use-after-free bug. Instead restart the verification if a sparse index is converted to a full index. This bug is triggered by a call to reset_head() in "git rebase --apply". Thanks to René Scharfe and Derrick Stolee for their help analyzing the problem. ==74345==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000001b20 at pc 0x557cbe82d3a2 bp 0x7ffdfee08090 sp 0x7ffdfee08080 READ of size 4 at 0x606000001b20 thread T0 #0 0x557cbe82d3a1 in verify_one /home/phil/src/git/cache-tree.c:863 #1 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #2 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #3 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #4 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910 #5 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250 #6 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87 #7 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 #8 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 #9 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 #10 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 #11 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 #12 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 #13 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) #14 0x557cbe5bcb8d in _start (/home/phil/src/git/git+0x1b9b8d) 0x606000001b20 is located 0 bytes inside of 56-byte region [0x606000001b20,0x606000001b58) freed by thread T0 here: #0 0x7fdd4bacff19 in __interceptor_free /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:127 #1 0x557cbe82af60 in cache_tree_free /home/phil/src/git/cache-tree.c:35 #2 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #3 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #4 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #5 0x557cbeb2557a in ensure_full_index /home/phil/src/git/sparse-index.c:310 #6 0x557cbea45c4a in index_name_stage_pos /home/phil/src/git/read-cache.c:588 #7 0x557cbe82ce37 in verify_one /home/phil/src/git/cache-tree.c:850 #8 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #9 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #10 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #11 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910 #12 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250 #13 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87 #14 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 #15 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 #16 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 #17 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 #18 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 #19 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 #20 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) previously allocated by thread T0 here: #0 0x7fdd4bad0459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x557cbebc1807 in xcalloc /home/phil/src/git/wrapper.c:140 #2 0x557cbe82b7d8 in cache_tree /home/phil/src/git/cache-tree.c:17 #3 0x557cbe82b7d8 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:763 #4 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764 #5 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764 #6 0x557cbe8304e1 in prime_cache_tree /home/phil/src/git/cache-tree.c:779 #7 0x557cbeab7fa7 in reset_head /home/phil/src/git/reset.c:85 #8 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 #9 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 #10 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 #11 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 #12 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 #13 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 #14 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a sparse index it is possible for the tree that is being verified to be freed while it is being verified. This happens when the index is sparse but the cache tree is not and index_name_pos() looks up a path from the cache tree that is a descendant of a sparse index entry. That triggers a call to ensure_full_index() which frees the cache tree that is being verified. Carrying on trying to verify the tree after this results in a use-after-free bug. Instead restart the verification if a sparse index is converted to a full index. This bug is triggered by a call to reset_head() in "git rebase --apply". Thanks to René Scharfe and Derrick Stolee for their help analyzing the problem. ==74345==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000001b20 at pc 0x557cbe82d3a2 bp 0x7ffdfee08090 sp 0x7ffdfee08080 READ of size 4 at 0x606000001b20 thread T0 #0 0x557cbe82d3a1 in verify_one /home/phil/src/git/cache-tree.c:863 #1 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #2 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #3 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #4 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910 #5 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250 #6 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87 #7 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 #8 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 #9 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 #10 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 #11 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 #12 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 #13 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) git-for-windows#14 0x557cbe5bcb8d in _start (/home/phil/src/git/git+0x1b9b8d) 0x606000001b20 is located 0 bytes inside of 56-byte region [0x606000001b20,0x606000001b58) freed by thread T0 here: #0 0x7fdd4bacff19 in __interceptor_free /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:127 #1 0x557cbe82af60 in cache_tree_free /home/phil/src/git/cache-tree.c:35 #2 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #3 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #4 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31 #5 0x557cbeb2557a in ensure_full_index /home/phil/src/git/sparse-index.c:310 #6 0x557cbea45c4a in index_name_stage_pos /home/phil/src/git/read-cache.c:588 #7 0x557cbe82ce37 in verify_one /home/phil/src/git/cache-tree.c:850 #8 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #9 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #10 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840 #11 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910 #12 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250 #13 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87 git-for-windows#14 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 git-for-windows#15 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 git-for-windows#16 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 git-for-windows#17 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 git-for-windows#18 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 git-for-windows#19 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 git-for-windows#20 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) previously allocated by thread T0 here: #0 0x7fdd4bad0459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x557cbebc1807 in xcalloc /home/phil/src/git/wrapper.c:140 #2 0x557cbe82b7d8 in cache_tree /home/phil/src/git/cache-tree.c:17 #3 0x557cbe82b7d8 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:763 #4 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764 #5 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764 #6 0x557cbe8304e1 in prime_cache_tree /home/phil/src/git/cache-tree.c:779 #7 0x557cbeab7fa7 in reset_head /home/phil/src/git/reset.c:85 #8 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074 #9 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461 #10 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714 #11 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781 #12 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912 #13 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52 git-for-windows#14 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24) Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
When fetching packfiles, we write a bunch of lockfiles for the packfiles we're writing into the repository. In order to not leave behind any cruft in case we exit or receive a signal, we register both an exit handler as well as signal handlers for common signals like SIGINT. These handlers will then unlink the locks and free the data structure tracking them. We have observed a deadlock in this logic though: (gdb) bt #0 __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:95 #1 0x00007f4932bea2cd in _int_free (av=0x7f4932f2eb20 <main_arena>, p=0x3e3e4200, have_lock=0) at malloc.c:3969 #2 0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975 #3 0x0000000000662ab1 in string_list_clear () #4 0x000000000044f5bc in unlock_pack_on_signal () #5 <signal handler called> #6 _int_free (av=0x7f4932f2eb20 <main_arena>, p=<optimized out>, have_lock=0) at malloc.c:4024 #7 0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975 #8 0x000000000065afd5 in strbuf_release () #9 0x000000000066ddb9 in delete_tempfile () #10 0x0000000000610d0b in files_transaction_cleanup.isra () #11 0x0000000000611718 in files_transaction_abort () #12 0x000000000060d2ef in ref_transaction_abort () #13 0x000000000060d441 in ref_transaction_prepare () #14 0x000000000060e0b5 in ref_transaction_commit () #15 0x00000000004511c2 in fetch_and_consume_refs () #16 0x000000000045279a in cmd_fetch () #17 0x0000000000407c48 in handle_builtin () #18 0x0000000000408df2 in cmd_main () #19 0x00000000004078b5 in main () The process was killed with a signal, which caused the signal handler to kick in and try free the data structures after we have unlinked the locks. It then deadlocks while calling free(3P). The root cause of this is that it is not allowed to call certain functions in async-signal handlers, as specified by signal-safety(7). Next to most I/O functions, this list of disallowed functions also includes memory-handling functions like malloc(3P) and free(3P) because they may not be reentrant. As a result, if we execute such functions in the signal handler, then they may operate on inconistent state and fail in unexpected ways. Fix this bug by not calling non-async-signal-safe functions when running in the signal handler. We're about to re-raise the signal anyway and will thus exit, so it's not much of a problem to keep the string list of lockfiles untouched. Note that it's fine though to call unlink(2), so we'll still clean up the lockfiles correctly. Signed-off-by: Patrick Steinhardt <ps@pks.im> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add virtual file system settings and hook proc. On index load, clear/set the skip worktree bits based on the virtual file system data. Use virtual file system data to update skip-worktree bit in unpack-trees. Use virtual file system data to exclude files and folders not explicitly requested. The hook was first contributed in private, but was extended via the following pull requests: git-for-windows#15 git-for-windows#27 git-for-windows#33 git-for-windows#70 Signed-off-by: Ben Peart <Ben.Peart@microsoft.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 Backtrace from the death is: #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: ``` #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Backtrace from the death is: ``` #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: ``` #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Backtrace from the death is: ``` #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: ``` #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Backtrace from the death is: ``` #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: ``` #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Backtrace from the death is: ``` #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: ``` #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Backtrace from the death is: ``` #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: ``` #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Backtrace from the death is: ``` #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
Add config option `windows.appendAtomically` Atomic append on windows is only supported on local disk files, and it may cause errors in other situations, e.g. network file system. If that is the case, this config option should be used to turn atomic append off. With these edits, status for old-style submodules with commondir needs to be fixed, due to the following. In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: ``` #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Backtrace from the death is: ``` #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Co-Authored-By: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: 孙卓识 <sunzhuoshi@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
Add config option `windows.appendAtomically` Atomic append on windows is only supported on local disk files, and it may cause errors in other situations, e.g. network file system. If that is the case, this config option should be used to turn atomic append off. With these edits, the status command for old-style submodules with commondir needs to be fixed, due to the following. In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, after the addition of the new config option, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh $ git status fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` $ GIT_DIR=.git git -C commonlibs/ status --porcelain=2 fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: ``` #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Backtrace from the death is: ``` #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 ``` Co-Authored-By: Johannes Schindelin <johannes.schindelin@gmx.de> Co-Authored-By: Andrey Zabavnikov <zabavnikov@gmail.com> Signed-off-by: 孙卓识 <sunzhuoshi@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
In some setups, old-style submodules (i.e. the ones with .git directory within theirs worktrees) with commondir can be of tremendous help. For example, commondir link can be used to avoid duplication of objects and also to keep branches in sync with multiple copies of the repo's worktree, while keeping the .git directory inside the worktree can be (ab?-)used to exploit the sharing of the same submodule worktree across different projects (this at least works on Windows with submodule directory being a directory junction, but having a junction is not relevant for reproducing the bug described below). Unfortunately, at the moment, when `git status` is run in the root repo of such a setup, it gives an output akin to this: ```sh fatal: unable to access '�??\1?/config': Invalid argument fatal: 'git status --porcelain=2' failed in submodule commonlibs ``` where `�??\1?` part of '�??\1?/config' varies from run to run, and `commonlibs` is the name of submodule's directory. Currently, when Git discovers old-style submodule , it spawns subprocess to get its status, like this one: ```sh cd commonlibs; unset GIT_PREFIX; GIT_DIR=.git git status --porcelain=2 ``` Unsurprisingly, the following output is also quite unexpected: ``` fatal: unable to access '`??L&?/config': Invalid argument ``` The core reason for these is that global repository field for commondir is not being cleared to `NULL` after being `free()`'d in `repo_set_commondir()`, which is precisely what this commit fixes. Regarding the further details of the case of investigation, this value of struct pointed by the global `the_repository` pointer is checked for being not-NULL down in the callstack in compatibility layer for MinGW in a function that is called by `repo_set_commondir()` before the `free()`'d value gets assigned in its body (i.e. the body of `repo_set_commondir()`). Backtrace from the check is: #0 mingw_open (filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:784 git-for-windows#1 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#2 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#3 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#4 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#5 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#6 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#7 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#8 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#9 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#10 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#11 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#12 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#13 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#14 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 Backtrace from the death is: #0 die_errno (fmt=0x<address-42> <result_type+2002> "unable to access '%s'") at usage.c:210 git-for-windows#1 0x<address-41> in access_or_die ( path=0x<address-40> "`\001\r��\004/config", mode=4, flag=0) at wrapper.c:667 git-for-windows#2 0x<address-39> in do_git_config_sequence (opts=0x<address-35>, fn=0x<address-37> <git_config_include>, data=0x<address-36>) at config.c:2142 git-for-windows#3 0x<address-38> in config_with_options ( fn=0x<address-37> <git_config_include>, data=0x<address-36>, config_source=0x0, opts=0x<address-35>) at config.c:2198 git-for-windows#4 0x<address-34> in repo_read_config (repo=0x<address-19> <the_repo>) at config.c:2524 git-for-windows#5 0x<address-33> in git_config_check_init ( repo=0x<address-19> <the_repo>) at config.c:2543 git-for-windows#6 0x<address-32> in repo_config_get_bool ( repo=0x<address-19> <the_repo>, key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2612 git-for-windows#7 0x<address-31> in git_config_get_bool ( key=0x<address-30> <pad+3116> "windows.appendatomically", dest=0x<address-29> <append_atomically>) at config.c:2714 git-for-windows#8 0x<address-28> in mingw_open ( filename=0x<address-25> ".git/commondir", oflags=0) at compat/mingw.c:785 git-for-windows#9 0x<address-27> in strbuf_read_file (sb=0x<address-26>, path=0x<address-25> ".git/commondir", hint=0) at strbuf.c:758 git-for-windows#10 0x<address-24> in get_common_dir_noenv (sb=0x<address-23>, gitdir=0x<address-22> ".git") at setup.c:313 git-for-windows#11 0x<address-21> in repo_set_commondir (repo=0x<address-19> <the_repo>, commondir=0x0) at repository.c:57 git-for-windows#12 0x<address-20> in repo_set_gitdir (repo=0x<address-19> <the_repo>, root=0x<address-15> ".git", o=0x<address-18>) at repository.c:76 git-for-windows#13 0x<address-17> in setup_git_env (git_dir=0x<address-15> ".git") at environment.c:179 git-for-windows#14 0x<address-16> in set_git_dir_1 (path=0x<address-15> ".git") at environment.c:334 git-for-windows#15 0x<address-14> in update_relative_gitdir (name=0x0, old_cwd=0x<address-13> "C:/Users/%username%/<root-repo-name>/commonlibs", new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs", data=0x0) at environment.c:348 git-for-windows#16 0x<address-12> in chdir_notify ( new_cwd=0x<address-11> "C:/Users/%username%/<root-repo-name>/commonlibs") at chdir-notify.c:72 git-for-windows#17 0x<address-10> in setup_work_tree () at setup.c:428 git-for-windows#18 0x<address-9> in run_builtin (p=0x<address-8> <commands+2856>, argc=2, argv=0x<address-2>) at git.c:458 git-for-windows#19 0x<address-7> in handle_builtin (argc=2, argv=0x<address-2>) at git.c:721 git-for-windows#20 0x<address-6> in run_argv (argcp=0x<address-5>, argv=0x<address-4>) at git.c:788 git-for-windows#21 0x<address-3> in cmd_main (argc=2, argv=0x<address-2>) at git.c:921 git-for-windows#22 0x<address-1> in main (argc=6, argv=0x<address-0>) at common-main.c:56 Signed-off-by: Andrey Zabavnikov <zabavnikov@gmail.com>
When "read_strategy_opts()" is called we may have populated the "opts->strategy" before, so we'll need to free() it to avoid leaking memory. We populate it before because we cal get_replay_opts() from within "rebase.c" with an already populated "opts", which we then copy. Then if we're doing a "rebase -i" the sequencer API itself will promptly clobber our alloc'd version of it with its own. If this code is changed to do, instead of the added free() here a: if (opts->strategy) opts->strategy = xstrdup("another leak"); We get a couple of stacktraces from -fsanitize=leak showing how we ended up clobbering the already allocated value, i.e.: Direct leak of 6 byte(s) in 1 object(s) allocated from: #0 0x7f2e8cd45545 in __interceptor_malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75 #1 0x7f2e8cb0fcaa in __GI___strdup string/strdup.c:42 #2 0x6c4778 in xstrdup wrapper.c:39 #3 0x66bcb8 in read_strategy_opts sequencer.c:2902 #4 0x66bf7b in read_populate_opts sequencer.c:2969 #5 0x6723f9 in sequencer_continue sequencer.c:5063 #6 0x4a4f74 in run_sequencer_rebase builtin/rebase.c:348 #7 0x4a64c8 in run_specific_rebase builtin/rebase.c:753 #8 0x4a9b8b in cmd_rebase builtin/rebase.c:1824 #9 0x407a32 in run_builtin git.c:466 #10 0x407e0a in handle_builtin git.c:721 #11 0x40803d in run_argv git.c:788 #12 0x40850f in cmd_main git.c:923 #13 0x4eee79 in main common-main.c:57 #14 0x7f2e8ca9f209 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #15 0x7f2e8ca9f2bb in __libc_start_main_impl ../csu/libc-start.c:389 #16 0x405fd0 in _start (git+0x405fd0) Direct leak of 4 byte(s) in 1 object(s) allocated from: #0 0x7f2e8cd45545 in __interceptor_malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75 #1 0x7f2e8cb0fcaa in __GI___strdup string/strdup.c:42 #2 0x6c4778 in xstrdup wrapper.c:39 #3 0x4a3c31 in xstrdup_or_null git-compat-util.h:1169 #4 0x4a447a in get_replay_opts builtin/rebase.c:163 #5 0x4a4f5b in run_sequencer_rebase builtin/rebase.c:346 #6 0x4a64c8 in run_specific_rebase builtin/rebase.c:753 #7 0x4a9b8b in cmd_rebase builtin/rebase.c:1824 #8 0x407a32 in run_builtin git.c:466 #9 0x407e0a in handle_builtin git.c:721 #10 0x40803d in run_argv git.c:788 #11 0x40850f in cmd_main git.c:923 #12 0x4eee79 in main common-main.c:57 #13 0x7f2e8ca9f209 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #14 0x7f2e8ca9f2bb in __libc_start_main_impl ../csu/libc-start.c:389 #15 0x405fd0 in _start (git+0x405fd0) This can be seen in e.g. the 4th test of "t3404-rebase-interactive.sh". In the larger picture the ownership of the "struct replay_opts" is quite a mess, e.g. in this case rebase.c's static "get_replay_opts()" function partially creates it, but nothing in rebase.c will free() it. The structure is "mostly owned" by the sequencer API, but it also expects to get these partially populated versions of it. It would be better to have rebase keep track of what it allocated, and free() that, and to pass that as a "const" to the sequencer API, which would copy what it needs to its own version, and to free() that. But doing so is a much larger change, and however messy the ownership boundary is here is consistent with what we're doing already, so let's just free() this to fix the leak. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>
When "read_strategy_opts()" is called we may have populated the "opts->strategy" before, so we'll need to free() it to avoid leaking memory. We populate it before because we cal get_replay_opts() from within "rebase.c" with an already populated "opts", which we then copy. Then if we're doing a "rebase -i" the sequencer API itself will promptly clobber our alloc'd version of it with its own. If this code is changed to do, instead of the added free() here a: if (opts->strategy) opts->strategy = xstrdup("another leak"); We get a couple of stacktraces from -fsanitize=leak showing how we ended up clobbering the already allocated value, i.e.: Direct leak of 6 byte(s) in 1 object(s) allocated from: #0 0x7f2e8cd45545 in __interceptor_malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75 #1 0x7f2e8cb0fcaa in __GI___strdup string/strdup.c:42 #2 0x6c4778 in xstrdup wrapper.c:39 #3 0x66bcb8 in read_strategy_opts sequencer.c:2902 #4 0x66bf7b in read_populate_opts sequencer.c:2969 #5 0x6723f9 in sequencer_continue sequencer.c:5063 #6 0x4a4f74 in run_sequencer_rebase builtin/rebase.c:348 #7 0x4a64c8 in run_specific_rebase builtin/rebase.c:753 #8 0x4a9b8b in cmd_rebase builtin/rebase.c:1824 #9 0x407a32 in run_builtin git.c:466 #10 0x407e0a in handle_builtin git.c:721 #11 0x40803d in run_argv git.c:788 #12 0x40850f in cmd_main git.c:923 #13 0x4eee79 in main common-main.c:57 #14 0x7f2e8ca9f209 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #15 0x7f2e8ca9f2bb in __libc_start_main_impl ../csu/libc-start.c:389 #16 0x405fd0 in _start (git+0x405fd0) Direct leak of 4 byte(s) in 1 object(s) allocated from: #0 0x7f2e8cd45545 in __interceptor_malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75 #1 0x7f2e8cb0fcaa in __GI___strdup string/strdup.c:42 #2 0x6c4778 in xstrdup wrapper.c:39 #3 0x4a3c31 in xstrdup_or_null git-compat-util.h:1169 #4 0x4a447a in get_replay_opts builtin/rebase.c:163 #5 0x4a4f5b in run_sequencer_rebase builtin/rebase.c:346 #6 0x4a64c8 in run_specific_rebase builtin/rebase.c:753 #7 0x4a9b8b in cmd_rebase builtin/rebase.c:1824 #8 0x407a32 in run_builtin git.c:466 #9 0x407e0a in handle_builtin git.c:721 #10 0x40803d in run_argv git.c:788 #11 0x40850f in cmd_main git.c:923 #12 0x4eee79 in main common-main.c:57 #13 0x7f2e8ca9f209 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #14 0x7f2e8ca9f2bb in __libc_start_main_impl ../csu/libc-start.c:389 #15 0x405fd0 in _start (git+0x405fd0) This can be seen in e.g. the 4th test of "t3404-rebase-interactive.sh". In the larger picture the ownership of the "struct replay_opts" is quite a mess, e.g. in this case rebase.c's static "get_replay_opts()" function partially creates it, but nothing in rebase.c will free() it. The structure is "mostly owned" by the sequencer API, but it also expects to get these partially populated versions of it. It would be better to have rebase keep track of what it allocated, and free() that, and to pass that as a "const" to the sequencer API, which would copy what it needs to its own version, and to free() that. But doing so is a much larger change, and however messy the ownership boundary is here is consistent with what we're doing already, so let's just free() this to fix the leak. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>
There is an out-of-bounds read possible when parsing gitattributes that have an attribute that is 2^31+1 bytes long. This is caused due to an integer overflow when we assign the result of strlen(3P) to an `int`, where we use the wrapped-around value in a subsequent call to memcpy(3P). The following code reproduces the issue: blob=$(perl -e 'print "a" x 2147483649 . " attr"' | git hash-object -w --stdin) git update-index --add --cacheinfo 100644,$blob,.gitattributes git check-attr --all file AddressSanitizer:DEADLYSIGNAL ================================================================= ==8451==ERROR: AddressSanitizer: SEGV on unknown address 0x7f93efa00800 (pc 0x7f94f1f8f082 bp 0x7ffddb59b3a0 sp 0x7ffddb59ab28 T0) ==8451==The signal is caused by a READ memory access. #0 0x7f94f1f8f082 (/usr/lib/libc.so.6+0x176082) #1 0x7f94f2047d9c in __interceptor_strspn /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:752 #2 0x560e190f7f26 in parse_attr_line attr.c:375 #3 0x560e190f9663 in handle_attr_line attr.c:660 #4 0x560e190f9ddd in read_attr_from_index attr.c:769 #5 0x560e190f9f14 in read_attr attr.c:797 #6 0x560e190fa24e in bootstrap_attr_stack attr.c:867 #7 0x560e190fa4a5 in prepare_attr_stack attr.c:902 #8 0x560e190fb5dc in collect_some_attrs attr.c:1097 #9 0x560e190fb93f in git_all_attrs attr.c:1128 #10 0x560e18e6136e in check_attr builtin/check-attr.c:67 #11 0x560e18e61c12 in cmd_check_attr builtin/check-attr.c:183 #12 0x560e18e15993 in run_builtin git.c:466 #13 0x560e18e16397 in handle_builtin git.c:721 #14 0x560e18e16b2b in run_argv git.c:788 #15 0x560e18e17991 in cmd_main git.c:926 #16 0x560e190ae2bd in main common-main.c:57 #17 0x7f94f1e3c28f (/usr/lib/libc.so.6+0x2328f) #18 0x7f94f1e3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #19 0x560e18e110e4 in _start ../sysdeps/x86_64/start.S:115 AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: SEGV (/usr/lib/libc.so.6+0x176082) ==8451==ABORTING Fix this bug by converting the variable to a `size_t` instead. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is possible to trigger an integer overflow when parsing attribute names when there are more than 2^31 of them for a single pattern. This can either lead to us dying due to trying to request too many bytes: blob=$(perl -e 'print "f" . " a=" x 2147483649' | git hash-object -w --stdin) git update-index --add --cacheinfo 100644,$blob,.gitattributes git attr-check --all file ================================================================= ==1022==ERROR: AddressSanitizer: requested allocation size 0xfffffff800000032 (0xfffffff800001038 after adjustments for alignment, red zones etc.) exceeds maximum supported size of 0x10000000000 (thread T0) #0 0x7fd3efabf411 in __interceptor_calloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77 #1 0x5563a0a1e3d3 in xcalloc wrapper.c:150 #2 0x5563a058d005 in parse_attr_line attr.c:384 #3 0x5563a058e661 in handle_attr_line attr.c:660 #4 0x5563a058eddb in read_attr_from_index attr.c:769 #5 0x5563a058ef12 in read_attr attr.c:797 #6 0x5563a058f24c in bootstrap_attr_stack attr.c:867 #7 0x5563a058f4a3 in prepare_attr_stack attr.c:902 #8 0x5563a05905da in collect_some_attrs attr.c:1097 #9 0x5563a059093d in git_all_attrs attr.c:1128 #10 0x5563a02f636e in check_attr builtin/check-attr.c:67 #11 0x5563a02f6c12 in cmd_check_attr builtin/check-attr.c:183 #12 0x5563a02aa993 in run_builtin git.c:466 #13 0x5563a02ab397 in handle_builtin git.c:721 #14 0x5563a02abb2b in run_argv git.c:788 #15 0x5563a02ac991 in cmd_main git.c:926 #16 0x5563a05432bd in main common-main.c:57 #17 0x7fd3ef82228f (/usr/lib/libc.so.6+0x2328f) ==1022==HINT: if you don't care about these errors you may set allocator_may_return_null=1 SUMMARY: AddressSanitizer: allocation-size-too-big /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77 in __interceptor_calloc ==1022==ABORTING Or, much worse, it can lead to an out-of-bounds write because we underallocate and then memcpy(3P) into an array: perl -e ' print "A " . "\rh="x2000000000; print "\rh="x2000000000; print "\rh="x294967294 . "\n" ' >.gitattributes git add .gitattributes git commit -am "evil attributes" $ git clone --quiet /path/to/repo ================================================================= ==15062==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000002550 at pc 0x5555559884d5 bp 0x7fffffffbc60 sp 0x7fffffffbc58 WRITE of size 8 at 0x602000002550 thread T0 #0 0x5555559884d4 in parse_attr_line attr.c:393 #1 0x5555559884d4 in handle_attr_line attr.c:660 #2 0x555555988902 in read_attr_from_index attr.c:784 #3 0x555555988902 in read_attr_from_index attr.c:747 #4 0x555555988a1d in read_attr attr.c:800 #5 0x555555989b0c in bootstrap_attr_stack attr.c:882 #6 0x555555989b0c in prepare_attr_stack attr.c:917 #7 0x555555989b0c in collect_some_attrs attr.c:1112 #8 0x55555598b141 in git_check_attr attr.c:1126 #9 0x555555a13004 in convert_attrs convert.c:1311 #10 0x555555a95e04 in checkout_entry_ca entry.c:553 #11 0x555555d58bf6 in checkout_entry entry.h:42 #12 0x555555d58bf6 in check_updates unpack-trees.c:480 #13 0x555555d5eb55 in unpack_trees unpack-trees.c:2040 #14 0x555555785ab7 in checkout builtin/clone.c:724 #15 0x555555785ab7 in cmd_clone builtin/clone.c:1384 #16 0x55555572443c in run_builtin git.c:466 #17 0x55555572443c in handle_builtin git.c:721 #18 0x555555727872 in run_argv git.c:788 #19 0x555555727872 in cmd_main git.c:926 #20 0x555555721fa0 in main common-main.c:57 #21 0x7ffff73f1d09 in __libc_start_main ../csu/libc-start.c:308 #22 0x555555723f39 in _start (git+0x1cff39) 0x602000002552 is located 0 bytes to the right of 2-byte region [0x602000002550,0x602000002552) allocated by thread T0 here: #0 0x7ffff768c037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x555555d7fff7 in xcalloc wrapper.c:150 #2 0x55555598815f in parse_attr_line attr.c:384 #3 0x55555598815f in handle_attr_line attr.c:660 #4 0x555555988902 in read_attr_from_index attr.c:784 #5 0x555555988902 in read_attr_from_index attr.c:747 #6 0x555555988a1d in read_attr attr.c:800 #7 0x555555989b0c in bootstrap_attr_stack attr.c:882 #8 0x555555989b0c in prepare_attr_stack attr.c:917 #9 0x555555989b0c in collect_some_attrs attr.c:1112 #10 0x55555598b141 in git_check_attr attr.c:1126 #11 0x555555a13004 in convert_attrs convert.c:1311 #12 0x555555a95e04 in checkout_entry_ca entry.c:553 #13 0x555555d58bf6 in checkout_entry entry.h:42 #14 0x555555d58bf6 in check_updates unpack-trees.c:480 #15 0x555555d5eb55 in unpack_trees unpack-trees.c:2040 #16 0x555555785ab7 in checkout builtin/clone.c:724 #17 0x555555785ab7 in cmd_clone builtin/clone.c:1384 #18 0x55555572443c in run_builtin git.c:466 #19 0x55555572443c in handle_builtin git.c:721 #20 0x555555727872 in run_argv git.c:788 #21 0x555555727872 in cmd_main git.c:926 #22 0x555555721fa0 in main common-main.c:57 #23 0x7ffff73f1d09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: heap-buffer-overflow attr.c:393 in parse_attr_line Shadow bytes around the buggy address: 0x0c047fff8450: fa fa 00 02 fa fa 00 07 fa fa fd fd fa fa 00 00 0x0c047fff8460: fa fa 02 fa fa fa fd fd fa fa 00 06 fa fa 05 fa 0x0c047fff8470: fa fa fd fd fa fa 00 02 fa fa 06 fa fa fa 05 fa 0x0c047fff8480: fa fa 07 fa fa fa fd fd fa fa 00 01 fa fa 00 02 0x0c047fff8490: fa fa 00 03 fa fa 00 fa fa fa 00 01 fa fa 00 03 =>0x0c047fff84a0: fa fa 00 01 fa fa 00 02 fa fa[02]fa fa fa fa fa 0x0c047fff84b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c047fff84c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c047fff84d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c047fff84e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c047fff84f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb Shadow gap: cc ==15062==ABORTING Fix this bug by using `size_t` instead to count the number of attributes so that this value cannot reasonably overflow without running out of memory before already. Reported-by: Markus Vervier <markus.vervier@x41-dsec.de> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When using a padding specifier in the pretty format passed to git-log(1) we need to calculate the string length in several places. These string lengths are stored in `int`s though, which means that these can easily overflow when the input lengths exceeds 2GB. This can ultimately lead to an out-of-bounds write when these are used in a call to memcpy(3P): ==8340==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7f1ec62f97fe at pc 0x7f2127e5f427 bp 0x7ffd3bd63de0 sp 0x7ffd3bd63588 WRITE of size 1 at 0x7f1ec62f97fe thread T0 #0 0x7f2127e5f426 in __interceptor_memcpy /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 #1 0x5628e96aa605 in format_and_pad_commit pretty.c:1762 #2 0x5628e96aa7f4 in format_commit_item pretty.c:1801 #3 0x5628e97cdb24 in strbuf_expand strbuf.c:429 #4 0x5628e96ab060 in repo_format_commit_message pretty.c:1869 #5 0x5628e96acd0f in pretty_print_commit pretty.c:2161 #6 0x5628e95a44c8 in show_log log-tree.c:781 #7 0x5628e95a76ba in log_tree_commit log-tree.c:1117 #8 0x5628e922bed5 in cmd_log_walk_no_free builtin/log.c:508 #9 0x5628e922c35b in cmd_log_walk builtin/log.c:549 #10 0x5628e922f1a2 in cmd_log builtin/log.c:883 #11 0x5628e9106993 in run_builtin git.c:466 #12 0x5628e9107397 in handle_builtin git.c:721 #13 0x5628e9107b07 in run_argv git.c:788 #14 0x5628e91088a7 in cmd_main git.c:923 #15 0x5628e939d682 in main common-main.c:57 #16 0x7f2127c3c28f (/usr/lib/libc.so.6+0x2328f) #17 0x7f2127c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #18 0x5628e91020e4 in _start ../sysdeps/x86_64/start.S:115 0x7f1ec62f97fe is located 2 bytes to the left of 4831838265-byte region [0x7f1ec62f9800,0x7f1fe62f9839) allocated by thread T0 here: #0 0x7f2127ebe7ea in __interceptor_realloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:85 #1 0x5628e98774d4 in xrealloc wrapper.c:136 #2 0x5628e97cb01c in strbuf_grow strbuf.c:99 #3 0x5628e97ccd42 in strbuf_addchars strbuf.c:327 #4 0x5628e96aa55c in format_and_pad_commit pretty.c:1761 #5 0x5628e96aa7f4 in format_commit_item pretty.c:1801 #6 0x5628e97cdb24 in strbuf_expand strbuf.c:429 #7 0x5628e96ab060 in repo_format_commit_message pretty.c:1869 #8 0x5628e96acd0f in pretty_print_commit pretty.c:2161 #9 0x5628e95a44c8 in show_log log-tree.c:781 #10 0x5628e95a76ba in log_tree_commit log-tree.c:1117 #11 0x5628e922bed5 in cmd_log_walk_no_free builtin/log.c:508 #12 0x5628e922c35b in cmd_log_walk builtin/log.c:549 #13 0x5628e922f1a2 in cmd_log builtin/log.c:883 #14 0x5628e9106993 in run_builtin git.c:466 #15 0x5628e9107397 in handle_builtin git.c:721 #16 0x5628e9107b07 in run_argv git.c:788 #17 0x5628e91088a7 in cmd_main git.c:923 #18 0x5628e939d682 in main common-main.c:57 #19 0x7f2127c3c28f (/usr/lib/libc.so.6+0x2328f) #20 0x7f2127c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #21 0x5628e91020e4 in _start ../sysdeps/x86_64/start.S:115 SUMMARY: AddressSanitizer: heap-buffer-overflow /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 in __interceptor_memcpy Shadow bytes around the buggy address: 0x0fe458c572a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0fe458c572b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0fe458c572c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0fe458c572d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0fe458c572e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa =>0x0fe458c572f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa[fa] 0x0fe458c57300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0fe458c57310: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0fe458c57320: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0fe458c57330: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0fe458c57340: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==8340==ABORTING The pretty format can also be used in `git archive` operations via the `export-subst` attribute. So this is what in our opinion makes this a critical issue in the context of Git forges which allow to download an archive of user supplied Git repositories. Fix this vulnerability by using `size_t` instead of `int` to track the string lengths. Add tests which detect this vulnerability when Git is compiled with the address sanitizer. Reported-by: Joern Schneeweisz <jschneeweisz@gitlab.com> Original-patch-by: Joern Schneeweisz <jschneeweisz@gitlab.com> Modified-by: Taylor Blau <me@ttalorr.com> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
With the `%>>(<N>)` pretty formatter, you can ask git-log(1) et al to steal spaces. To do so we need to look ahead of the next token to see whether there are spaces there. This loop takes into account ANSI sequences that end with an `m`, and if it finds any it will skip them until it finds the first space. While doing so it does not take into account the buffer's limits though and easily does an out-of-bounds read. Add a test that hits this behaviour. While we don't have an easy way to verify this, the test causes the following failure when run with `SANITIZE=address`: ==37941==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000000baf at pc 0x55ba6f88e0d0 bp 0x7ffc84c50d20 sp 0x7ffc84c50d10 READ of size 1 at 0x603000000baf thread T0 #0 0x55ba6f88e0cf in format_and_pad_commit pretty.c:1712 #1 0x55ba6f88e7b4 in format_commit_item pretty.c:1801 #2 0x55ba6f9b1ae4 in strbuf_expand strbuf.c:429 #3 0x55ba6f88f020 in repo_format_commit_message pretty.c:1869 #4 0x55ba6f890ccf in pretty_print_commit pretty.c:2161 #5 0x55ba6f7884c8 in show_log log-tree.c:781 #6 0x55ba6f78b6ba in log_tree_commit log-tree.c:1117 #7 0x55ba6f40fed5 in cmd_log_walk_no_free builtin/log.c:508 #8 0x55ba6f41035b in cmd_log_walk builtin/log.c:549 #9 0x55ba6f4131a2 in cmd_log builtin/log.c:883 #10 0x55ba6f2ea993 in run_builtin git.c:466 #11 0x55ba6f2eb397 in handle_builtin git.c:721 #12 0x55ba6f2ebb07 in run_argv git.c:788 #13 0x55ba6f2ec8a7 in cmd_main git.c:923 #14 0x55ba6f581682 in main common-main.c:57 #15 0x7f2d08c3c28f (/usr/lib/libc.so.6+0x2328f) #16 0x7f2d08c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #17 0x55ba6f2e60e4 in _start ../sysdeps/x86_64/start.S:115 0x603000000baf is located 1 bytes to the left of 24-byte region [0x603000000bb0,0x603000000bc8) allocated by thread T0 here: #0 0x7f2d08ebe7ea in __interceptor_realloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:85 #1 0x55ba6fa5b494 in xrealloc wrapper.c:136 #2 0x55ba6f9aefdc in strbuf_grow strbuf.c:99 #3 0x55ba6f9b0a06 in strbuf_add strbuf.c:298 #4 0x55ba6f9b1a25 in strbuf_expand strbuf.c:418 #5 0x55ba6f88f020 in repo_format_commit_message pretty.c:1869 #6 0x55ba6f890ccf in pretty_print_commit pretty.c:2161 #7 0x55ba6f7884c8 in show_log log-tree.c:781 #8 0x55ba6f78b6ba in log_tree_commit log-tree.c:1117 #9 0x55ba6f40fed5 in cmd_log_walk_no_free builtin/log.c:508 #10 0x55ba6f41035b in cmd_log_walk builtin/log.c:549 #11 0x55ba6f4131a2 in cmd_log builtin/log.c:883 #12 0x55ba6f2ea993 in run_builtin git.c:466 #13 0x55ba6f2eb397 in handle_builtin git.c:721 #14 0x55ba6f2ebb07 in run_argv git.c:788 #15 0x55ba6f2ec8a7 in cmd_main git.c:923 #16 0x55ba6f581682 in main common-main.c:57 #17 0x7f2d08c3c28f (/usr/lib/libc.so.6+0x2328f) #18 0x7f2d08c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #19 0x55ba6f2e60e4 in _start ../sysdeps/x86_64/start.S:115 SUMMARY: AddressSanitizer: heap-buffer-overflow pretty.c:1712 in format_and_pad_commit Shadow bytes around the buggy address: 0x0c067fff8120: fa fa fd fd fd fa fa fa fd fd fd fa fa fa fd fd 0x0c067fff8130: fd fd fa fa fd fd fd fd fa fa fd fd fd fa fa fa 0x0c067fff8140: fd fd fd fa fa fa fd fd fd fa fa fa fd fd fd fa 0x0c067fff8150: fa fa fd fd fd fd fa fa 00 00 00 fa fa fa fd fd 0x0c067fff8160: fd fa fa fa fd fd fd fa fa fa fd fd fd fa fa fa =>0x0c067fff8170: fd fd fd fa fa[fa]00 00 00 fa fa fa 00 00 00 fa 0x0c067fff8180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c067fff8190: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c067fff81a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c067fff81b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c067fff81c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb Luckily enough, this would only cause us to copy the out-of-bounds data into the formatted commit in case we really had an ANSI sequence preceding our buffer. So this bug likely has no security consequences. Fix it regardless by not traversing past the buffer's start. Reported-by: Patrick Steinhardt <ps@pks.im> Reported-by: Eric Sesterhenn <eric.sesterhenn@x41-dsec.de> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
An out-of-bounds read can be triggered when parsing an incomplete padding format string passed via `--pretty=format` or in Git archives when files are marked with the `export-subst` gitattribute. This bug exists since we have introduced support for truncating output via the `trunc` keyword a7f01c6 (pretty: support truncating in %>, %< and %><, 2013-04-19). Before this commit, we used to find the end of the formatting string by using strchr(3P). This function returns a `NULL` pointer in case the character in question wasn't found. The subsequent check whether any character was found thus simply checked the returned pointer. After the commit we switched to strcspn(3P) though, which only returns the offset to the first found character or to the trailing NUL byte. As the end pointer is now computed by adding the offset to the start pointer it won't be `NULL` anymore, and as a consequence the check doesn't do anything anymore. The out-of-bounds data that is being read can in fact end up in the formatted string. As a consequence, it is possible to leak memory contents either by calling git-log(1) or via git-archive(1) when any of the archived files is marked with the `export-subst` gitattribute. ==10888==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000000398 at pc 0x7f0356047cb2 bp 0x7fff3ffb95d0 sp 0x7fff3ffb8d78 READ of size 1 at 0x602000000398 thread T0 #0 0x7f0356047cb1 in __interceptor_strchrnul /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:725 #1 0x563b7cec9a43 in strbuf_expand strbuf.c:417 #2 0x563b7cda7060 in repo_format_commit_message pretty.c:1869 #3 0x563b7cda8d0f in pretty_print_commit pretty.c:2161 #4 0x563b7cca04c8 in show_log log-tree.c:781 #5 0x563b7cca36ba in log_tree_commit log-tree.c:1117 #6 0x563b7c927ed5 in cmd_log_walk_no_free builtin/log.c:508 #7 0x563b7c92835b in cmd_log_walk builtin/log.c:549 #8 0x563b7c92b1a2 in cmd_log builtin/log.c:883 #9 0x563b7c802993 in run_builtin git.c:466 #10 0x563b7c803397 in handle_builtin git.c:721 #11 0x563b7c803b07 in run_argv git.c:788 #12 0x563b7c8048a7 in cmd_main git.c:923 #13 0x563b7ca99682 in main common-main.c:57 #14 0x7f0355e3c28f (/usr/lib/libc.so.6+0x2328f) #15 0x7f0355e3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #16 0x563b7c7fe0e4 in _start ../sysdeps/x86_64/start.S:115 0x602000000398 is located 0 bytes to the right of 8-byte region [0x602000000390,0x602000000398) allocated by thread T0 here: #0 0x7f0356072faa in __interceptor_strdup /usr/src/debug/gcc/libsanitizer/asan/asan_interceptors.cpp:439 #1 0x563b7cf7317c in xstrdup wrapper.c:39 #2 0x563b7cd9a06a in save_user_format pretty.c:40 #3 0x563b7cd9b3e5 in get_commit_format pretty.c:173 #4 0x563b7ce54ea0 in handle_revision_opt revision.c:2456 #5 0x563b7ce597c9 in setup_revisions revision.c:2850 #6 0x563b7c9269e0 in cmd_log_init_finish builtin/log.c:269 #7 0x563b7c927362 in cmd_log_init builtin/log.c:348 #8 0x563b7c92b193 in cmd_log builtin/log.c:882 #9 0x563b7c802993 in run_builtin git.c:466 #10 0x563b7c803397 in handle_builtin git.c:721 #11 0x563b7c803b07 in run_argv git.c:788 #12 0x563b7c8048a7 in cmd_main git.c:923 #13 0x563b7ca99682 in main common-main.c:57 #14 0x7f0355e3c28f (/usr/lib/libc.so.6+0x2328f) #15 0x7f0355e3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #16 0x563b7c7fe0e4 in _start ../sysdeps/x86_64/start.S:115 SUMMARY: AddressSanitizer: heap-buffer-overflow /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:725 in __interceptor_strchrnul Shadow bytes around the buggy address: 0x0c047fff8020: fa fa fd fd fa fa 00 06 fa fa 05 fa fa fa fd fd 0x0c047fff8030: fa fa 00 02 fa fa 06 fa fa fa 05 fa fa fa fd fd 0x0c047fff8040: fa fa 00 07 fa fa 03 fa fa fa fd fd fa fa 00 00 0x0c047fff8050: fa fa 00 01 fa fa fd fd fa fa 00 00 fa fa 00 01 0x0c047fff8060: fa fa 00 06 fa fa 00 06 fa fa 05 fa fa fa 05 fa =>0x0c047fff8070: fa fa 00[fa]fa fa fd fa fa fa fd fd fa fa fd fd 0x0c047fff8080: fa fa fd fd fa fa 00 00 fa fa 00 fa fa fa fd fa 0x0c047fff8090: fa fa fd fd fa fa 00 00 fa fa fa fa fa fa fa fa 0x0c047fff80a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c047fff80b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c047fff80c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==10888==ABORTING Fix this bug by checking whether `end` points at the trailing NUL byte. Add a test which catches this out-of-bounds read and which demonstrates that we used to write out-of-bounds data into the formatted message. Reported-by: Markus Vervier <markus.vervier@x41-dsec.de> Original-patch-by: Markus Vervier <markus.vervier@x41-dsec.de> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The return type of both `utf8_strwidth()` and `utf8_strnwidth()` is `int`, but we operate on string lengths which are typically of type `size_t`. This means that when the string is longer than `INT_MAX`, we will overflow and thus return a negative result. This can lead to an out-of-bounds write with `--pretty=format:%<1)%B` and a commit message that is 2^31+1 bytes long: ================================================================= ==26009==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000001168 at pc 0x7f95c4e5f427 bp 0x7ffd8541c900 sp 0x7ffd8541c0a8 WRITE of size 2147483649 at 0x603000001168 thread T0 #0 0x7f95c4e5f426 in __interceptor_memcpy /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 #1 0x5612bbb1068c in format_and_pad_commit pretty.c:1763 #2 0x5612bbb1087a in format_commit_item pretty.c:1801 #3 0x5612bbc33bab in strbuf_expand strbuf.c:429 #4 0x5612bbb110e7 in repo_format_commit_message pretty.c:1869 #5 0x5612bbb12d96 in pretty_print_commit pretty.c:2161 #6 0x5612bba0a4d5 in show_log log-tree.c:781 #7 0x5612bba0d6c7 in log_tree_commit log-tree.c:1117 #8 0x5612bb691ed5 in cmd_log_walk_no_free builtin/log.c:508 #9 0x5612bb69235b in cmd_log_walk builtin/log.c:549 #10 0x5612bb6951a2 in cmd_log builtin/log.c:883 #11 0x5612bb56c993 in run_builtin git.c:466 #12 0x5612bb56d397 in handle_builtin git.c:721 #13 0x5612bb56db07 in run_argv git.c:788 #14 0x5612bb56e8a7 in cmd_main git.c:923 #15 0x5612bb803682 in main common-main.c:57 #16 0x7f95c4c3c28f (/usr/lib/libc.so.6+0x2328f) #17 0x7f95c4c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #18 0x5612bb5680e4 in _start ../sysdeps/x86_64/start.S:115 0x603000001168 is located 0 bytes to the right of 24-byte region [0x603000001150,0x603000001168) allocated by thread T0 here: #0 0x7f95c4ebe7ea in __interceptor_realloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:85 #1 0x5612bbcdd556 in xrealloc wrapper.c:136 #2 0x5612bbc310a3 in strbuf_grow strbuf.c:99 #3 0x5612bbc32acd in strbuf_add strbuf.c:298 #4 0x5612bbc33aec in strbuf_expand strbuf.c:418 #5 0x5612bbb110e7 in repo_format_commit_message pretty.c:1869 #6 0x5612bbb12d96 in pretty_print_commit pretty.c:2161 #7 0x5612bba0a4d5 in show_log log-tree.c:781 #8 0x5612bba0d6c7 in log_tree_commit log-tree.c:1117 #9 0x5612bb691ed5 in cmd_log_walk_no_free builtin/log.c:508 #10 0x5612bb69235b in cmd_log_walk builtin/log.c:549 #11 0x5612bb6951a2 in cmd_log builtin/log.c:883 #12 0x5612bb56c993 in run_builtin git.c:466 #13 0x5612bb56d397 in handle_builtin git.c:721 #14 0x5612bb56db07 in run_argv git.c:788 #15 0x5612bb56e8a7 in cmd_main git.c:923 #16 0x5612bb803682 in main common-main.c:57 #17 0x7f95c4c3c28f (/usr/lib/libc.so.6+0x2328f) SUMMARY: AddressSanitizer: heap-buffer-overflow /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 in __interceptor_memcpy Shadow bytes around the buggy address: 0x0c067fff81d0: fd fd fd fa fa fa fd fd fd fa fa fa fd fd fd fa 0x0c067fff81e0: fa fa fd fd fd fd fa fa fd fd fd fd fa fa fd fd 0x0c067fff81f0: fd fa fa fa fd fd fd fa fa fa fd fd fd fa fa fa 0x0c067fff8200: fd fd fd fa fa fa fd fd fd fd fa fa 00 00 00 fa 0x0c067fff8210: fa fa fd fd fd fa fa fa fd fd fd fa fa fa fd fd =>0x0c067fff8220: fd fa fa fa fd fd fd fa fa fa 00 00 00[fa]fa fa 0x0c067fff8230: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c067fff8240: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c067fff8250: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c067fff8260: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c067fff8270: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==26009==ABORTING Now the proper fix for this would be to convert both functions to return an `size_t` instead of an `int`. But given that this commit may be part of a security release, let's instead do the minimal viable fix and die in case we see an overflow. Add a test that would have previously caused us to crash. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When t5583-push-branches.sh was originally introduced via 425b4d7 (push: introduce '--branches' option, 2023-05-06), it was not leak-free. In fact, the test did not even run correctly until 022fbb6 (t5583: fix shebang line, 2023-05-12), but after applying that patch, we see a failure at t5583.8: ==2529087==ERROR: LeakSanitizer: detected memory leaks Direct leak of 384 byte(s) in 1 object(s) allocated from: #0 0x7fb536330986 in __interceptor_realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98 #1 0x55e07606cbf9 in xrealloc wrapper.c:140 #2 0x55e075fb6cb3 in prio_queue_put prio-queue.c:42 #3 0x55e075ec81cb in get_reachable_subset commit-reach.c:917 #4 0x55e075fe9cce in add_missing_tags remote.c:1518 #5 0x55e075fea1e4 in match_push_refs remote.c:1665 #6 0x55e076050a8e in transport_push transport.c:1378 #7 0x55e075e2eb74 in push_with_options builtin/push.c:401 #8 0x55e075e2edb0 in do_push builtin/push.c:458 #9 0x55e075e2ff7a in cmd_push builtin/push.c:702 #10 0x55e075d8aaf0 in run_builtin git.c:452 #11 0x55e075d8af08 in handle_builtin git.c:706 #12 0x55e075d8b12c in run_argv git.c:770 #13 0x55e075d8b6a0 in cmd_main git.c:905 #14 0x55e075e81f07 in main common-main.c:60 #15 0x7fb5360ab6c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #16 0x7fb5360ab784 in __libc_start_main_impl ../csu/libc-start.c:360 #17 0x55e075d88f40 in _start (git+0x1ff40) (BuildId: 38ad998b85a535e786129979443630d025ec2453) SUMMARY: LeakSanitizer: 384 byte(s) leaked in 1 allocation(s). This leak was addressed independently via 68b5117 (commit-reach: fix memory leak in get_reachable_subset(), 2023-06-03), which makes t5583 leak-free. But t5583 was not in the tree when 68b5117 was written, and the two only met after the latter was merged back in via 693bde4 (Merge branch 'mh/commit-reach-get-reachable-plug-leak', 2023-06-20). At that point, t5583 was leak-free. Let's mark it as such accordingly. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When t5583-push-branches.sh was originally introduced via 425b4d7 (push: introduce '--branches' option, 2023-05-06), it was not leak-free. In fact, the test did not even run correctly until 022fbb6 (t5583: fix shebang line, 2023-05-12), but after applying that patch, we see a failure at t5583.8: ==2529087==ERROR: LeakSanitizer: detected memory leaks Direct leak of 384 byte(s) in 1 object(s) allocated from: #0 0x7fb536330986 in __interceptor_realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98 #1 0x55e07606cbf9 in xrealloc wrapper.c:140 #2 0x55e075fb6cb3 in prio_queue_put prio-queue.c:42 #3 0x55e075ec81cb in get_reachable_subset commit-reach.c:917 #4 0x55e075fe9cce in add_missing_tags remote.c:1518 #5 0x55e075fea1e4 in match_push_refs remote.c:1665 #6 0x55e076050a8e in transport_push transport.c:1378 #7 0x55e075e2eb74 in push_with_options builtin/push.c:401 #8 0x55e075e2edb0 in do_push builtin/push.c:458 #9 0x55e075e2ff7a in cmd_push builtin/push.c:702 #10 0x55e075d8aaf0 in run_builtin git.c:452 #11 0x55e075d8af08 in handle_builtin git.c:706 #12 0x55e075d8b12c in run_argv git.c:770 #13 0x55e075d8b6a0 in cmd_main git.c:905 #14 0x55e075e81f07 in main common-main.c:60 #15 0x7fb5360ab6c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #16 0x7fb5360ab784 in __libc_start_main_impl ../csu/libc-start.c:360 #17 0x55e075d88f40 in _start (git+0x1ff40) (BuildId: 38ad998b85a535e786129979443630d025ec2453) SUMMARY: LeakSanitizer: 384 byte(s) leaked in 1 allocation(s). This leak was addressed independently via 68b5117 (commit-reach: fix memory leak in get_reachable_subset(), 2023-06-03), which makes t5583 leak-free. But t5583 was not in the tree when 68b5117 was written, and the two only met after the latter was merged back in via 693bde4 (Merge branch 'mh/commit-reach-get-reachable-plug-leak', 2023-06-20). At that point, t5583 was leak-free. Let's mark it as such accordingly. Signed-off-by: Taylor Blau <me@ttaylorr.com> Acked-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Memory sanitizer (msan) is detecting a use of an uninitialized variable (`size`) in `read_attr_from_index`: ==2268==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x5651f3416504 in read_attr_from_index git/attr.c:868:11 #1 0x5651f3415530 in read_attr git/attr.c #2 0x5651f3413d74 in bootstrap_attr_stack git/attr.c:968:6 #3 0x5651f3413d74 in prepare_attr_stack git/attr.c:1004:2 #4 0x5651f3413d74 in collect_some_attrs git/attr.c:1199:2 #5 0x5651f3413144 in git_check_attr git/attr.c:1345:2 #6 0x5651f34728da in convert_attrs git/convert.c:1320:2 #7 0x5651f3473425 in would_convert_to_git_filter_fd git/convert.c:1373:2 #8 0x5651f357a35e in index_fd git/object-file.c:2630:34 #9 0x5651f357aa15 in index_path git/object-file.c:2657:7 #10 0x5651f35db9d9 in add_to_index git/read-cache.c:766:7 #11 0x5651f35dc170 in add_file_to_index git/read-cache.c:799:9 #12 0x5651f321f9b2 in add_files git/builtin/add.c:346:7 #13 0x5651f321f9b2 in cmd_add git/builtin/add.c:565:18 #14 0x5651f321d327 in run_builtin git/git.c:474:11 #15 0x5651f321bc9e in handle_builtin git/git.c:729:3 #16 0x5651f321a792 in run_argv git/git.c:793:4 #17 0x5651f321a792 in cmd_main git/git.c:928:19 #18 0x5651f33dde1f in main git/common-main.c:62:11 The issue exists because `size` is an output parameter from `read_blob_data_from_index`, but it's only modified if `read_blob_data_from_index` returns non-NULL. The read of `size` when calling `read_attr_from_buf` unconditionally may read from an uninitialized value. `read_attr_from_buf` checks that `buf` is non-NULL before reading from `size`, but by then it's already too late: the uninitialized read will have happened already. Furthermore, there's no guarantee that the compiler won't reorder things so that it checks `size` before checking `!buf`. Make the call to `read_attr_from_buf` conditional on `buf` being non-NULL, ensuring that `size` is not read if it's never set. Signed-off-by: Kyle Lippincott <spectral@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add virtual file system settings and hook proc. On index load, clear/set the skip worktree bits based on the virtual file system data. Use virtual file system data to update skip-worktree bit in unpack-trees. Use virtual file system data to exclude files and folders not explicitly requested. The hook was first contributed in private, but was extended via the following pull requests: git-for-windows#15 git-for-windows#27 git-for-windows#33 git-for-windows#70 Signed-off-by: Ben Peart <Ben.Peart@microsoft.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
It was recently reported that concurrent reads and writes may cause the reftable backend to segfault. The root cause of this is that we do not properly keep track of reftable readers across reloads. Suppose that you have a reftable iterator and then decide to reload the stack while iterating through the iterator. When the stack has been rewritten since we have created the iterator, then we would end up discarding a subset of readers that may still be in use by the iterator. The consequence is that we now try to reference deallocated memory, which of course segfaults. One way to trigger this is in t5616, where some background maintenance jobs have been leaking from one test into another. This leads to stack traces like the following one: + git -c protocol.version=0 -C pc1 fetch --filter=blob:limit=29999 --refetch origin AddressSanitizer:DEADLYSIGNAL ================================================================= ==657994==ERROR: AddressSanitizer: SEGV on unknown address 0x7fa0f0ec6089 (pc 0x55f23e52ddf9 bp 0x7ffe7bfa1700 sp 0x7ffe7bfa1700 T0) ==657994==The signal is caused by a READ memory access. #0 0x55f23e52ddf9 in get_var_int reftable/record.c:29 #1 0x55f23e53295e in reftable_decode_keylen reftable/record.c:170 #2 0x55f23e532cc0 in reftable_decode_key reftable/record.c:194 #3 0x55f23e54e72e in block_iter_next reftable/block.c:398 #4 0x55f23e5573dc in table_iter_next_in_block reftable/reader.c:240 #5 0x55f23e5573dc in table_iter_next reftable/reader.c:355 #6 0x55f23e5573dc in table_iter_next reftable/reader.c:339 #7 0x55f23e551283 in merged_iter_advance_subiter reftable/merged.c:69 #8 0x55f23e55169e in merged_iter_next_entry reftable/merged.c:123 #9 0x55f23e55169e in merged_iter_next_void reftable/merged.c:172 #10 0x55f23e537625 in reftable_iterator_next_ref reftable/generic.c:175 #11 0x55f23e2cf9c6 in reftable_ref_iterator_advance refs/reftable-backend.c:464 #12 0x55f23e2d996e in ref_iterator_advance refs/iterator.c:13 #13 0x55f23e2d996e in do_for_each_ref_iterator refs/iterator.c:452 #14 0x55f23dca6767 in get_ref_map builtin/fetch.c:623 #15 0x55f23dca6767 in do_fetch builtin/fetch.c:1659 #16 0x55f23dca6767 in fetch_one builtin/fetch.c:2133 #17 0x55f23dca6767 in cmd_fetch builtin/fetch.c:2432 #18 0x55f23dba7764 in run_builtin git.c:484 #19 0x55f23dba7764 in handle_builtin git.c:741 #20 0x55f23dbab61e in run_argv git.c:805 #21 0x55f23dbab61e in cmd_main git.c:1000 #22 0x55f23dba4781 in main common-main.c:64 #23 0x7fa0f063fc89 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #24 0x7fa0f063fd44 in __libc_start_main_impl ../csu/libc-start.c:360 #25 0x55f23dba6ad0 in _start (git+0xadfad0) (BuildId: 803b2b7f59beb03d7849fb8294a8e2145dd4aa27) While it is somewhat awkward that the maintenance processes survive tests in the first place, it is totally expected that reftables should work alright with concurrent writers. Seemingly they don't. The only underlying resource that we need to care about in this context is the reftable reader, which is responsible for reading a single table from disk. These readers get discarded immediately (unless reused) when calling `reftable_stack_reload()`, which is wrong. We can only close them once we know that there are no iterators using them anymore. Prepare for a fix by converting the reftable readers to be refcounted. Reported-by: Jeff King <peff@peff.net> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
It was recently reported that concurrent reads and writes may cause the reftable backend to segfault. The root cause of this is that we do not properly keep track of reftable readers across reloads. Suppose that you have a reftable iterator and then decide to reload the stack while iterating through the iterator. When the stack has been rewritten since we have created the iterator, then we would end up discarding a subset of readers that may still be in use by the iterator. The consequence is that we now try to reference deallocated memory, which of course segfaults. One way to trigger this is in t5616, where some background maintenance jobs have been leaking from one test into another. This leads to stack traces like the following one: + git -c protocol.version=0 -C pc1 fetch --filter=blob:limit=29999 --refetch origin AddressSanitizer:DEADLYSIGNAL ================================================================= ==657994==ERROR: AddressSanitizer: SEGV on unknown address 0x7fa0f0ec6089 (pc 0x55f23e52ddf9 bp 0x7ffe7bfa1700 sp 0x7ffe7bfa1700 T0) ==657994==The signal is caused by a READ memory access. #0 0x55f23e52ddf9 in get_var_int reftable/record.c:29 #1 0x55f23e53295e in reftable_decode_keylen reftable/record.c:170 #2 0x55f23e532cc0 in reftable_decode_key reftable/record.c:194 #3 0x55f23e54e72e in block_iter_next reftable/block.c:398 #4 0x55f23e5573dc in table_iter_next_in_block reftable/reader.c:240 #5 0x55f23e5573dc in table_iter_next reftable/reader.c:355 #6 0x55f23e5573dc in table_iter_next reftable/reader.c:339 #7 0x55f23e551283 in merged_iter_advance_subiter reftable/merged.c:69 #8 0x55f23e55169e in merged_iter_next_entry reftable/merged.c:123 #9 0x55f23e55169e in merged_iter_next_void reftable/merged.c:172 #10 0x55f23e537625 in reftable_iterator_next_ref reftable/generic.c:175 #11 0x55f23e2cf9c6 in reftable_ref_iterator_advance refs/reftable-backend.c:464 #12 0x55f23e2d996e in ref_iterator_advance refs/iterator.c:13 #13 0x55f23e2d996e in do_for_each_ref_iterator refs/iterator.c:452 #14 0x55f23dca6767 in get_ref_map builtin/fetch.c:623 #15 0x55f23dca6767 in do_fetch builtin/fetch.c:1659 #16 0x55f23dca6767 in fetch_one builtin/fetch.c:2133 #17 0x55f23dca6767 in cmd_fetch builtin/fetch.c:2432 #18 0x55f23dba7764 in run_builtin git.c:484 #19 0x55f23dba7764 in handle_builtin git.c:741 #20 0x55f23dbab61e in run_argv git.c:805 #21 0x55f23dbab61e in cmd_main git.c:1000 #22 0x55f23dba4781 in main common-main.c:64 #23 0x7fa0f063fc89 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #24 0x7fa0f063fd44 in __libc_start_main_impl ../csu/libc-start.c:360 #25 0x55f23dba6ad0 in _start (git+0xadfad0) (BuildId: 803b2b7f59beb03d7849fb8294a8e2145dd4aa27) While it is somewhat awkward that the maintenance processes survive tests in the first place, it is totally expected that reftables should work alright with concurrent writers. Seemingly they don't. The only underlying resource that we need to care about in this context is the reftable reader, which is responsible for reading a single table from disk. These readers get discarded immediately (unless reused) when calling `reftable_stack_reload()`, which is wrong. We can only close them once we know that there are no iterators using them anymore. Prepare for a fix by converting the reftable readers to be refcounted. Reported-by: Jeff King <peff@peff.net> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
It was recently reported that concurrent reads and writes may cause the reftable backend to segfault. The root cause of this is that we do not properly keep track of reftable readers across reloads. Suppose that you have a reftable iterator and then decide to reload the stack while iterating through the iterator. When the stack has been rewritten since we have created the iterator, then we would end up discarding a subset of readers that may still be in use by the iterator. The consequence is that we now try to reference deallocated memory, which of course segfaults. One way to trigger this is in t5616, where some background maintenance jobs have been leaking from one test into another. This leads to stack traces like the following one: + git -c protocol.version=0 -C pc1 fetch --filter=blob:limit=29999 --refetch origin AddressSanitizer:DEADLYSIGNAL ================================================================= ==657994==ERROR: AddressSanitizer: SEGV on unknown address 0x7fa0f0ec6089 (pc 0x55f23e52ddf9 bp 0x7ffe7bfa1700 sp 0x7ffe7bfa1700 T0) ==657994==The signal is caused by a READ memory access. #0 0x55f23e52ddf9 in get_var_int reftable/record.c:29 #1 0x55f23e53295e in reftable_decode_keylen reftable/record.c:170 #2 0x55f23e532cc0 in reftable_decode_key reftable/record.c:194 #3 0x55f23e54e72e in block_iter_next reftable/block.c:398 #4 0x55f23e5573dc in table_iter_next_in_block reftable/reader.c:240 #5 0x55f23e5573dc in table_iter_next reftable/reader.c:355 #6 0x55f23e5573dc in table_iter_next reftable/reader.c:339 #7 0x55f23e551283 in merged_iter_advance_subiter reftable/merged.c:69 #8 0x55f23e55169e in merged_iter_next_entry reftable/merged.c:123 #9 0x55f23e55169e in merged_iter_next_void reftable/merged.c:172 #10 0x55f23e537625 in reftable_iterator_next_ref reftable/generic.c:175 #11 0x55f23e2cf9c6 in reftable_ref_iterator_advance refs/reftable-backend.c:464 #12 0x55f23e2d996e in ref_iterator_advance refs/iterator.c:13 #13 0x55f23e2d996e in do_for_each_ref_iterator refs/iterator.c:452 #14 0x55f23dca6767 in get_ref_map builtin/fetch.c:623 #15 0x55f23dca6767 in do_fetch builtin/fetch.c:1659 #16 0x55f23dca6767 in fetch_one builtin/fetch.c:2133 #17 0x55f23dca6767 in cmd_fetch builtin/fetch.c:2432 #18 0x55f23dba7764 in run_builtin git.c:484 #19 0x55f23dba7764 in handle_builtin git.c:741 #20 0x55f23dbab61e in run_argv git.c:805 #21 0x55f23dbab61e in cmd_main git.c:1000 #22 0x55f23dba4781 in main common-main.c:64 #23 0x7fa0f063fc89 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #24 0x7fa0f063fd44 in __libc_start_main_impl ../csu/libc-start.c:360 #25 0x55f23dba6ad0 in _start (git+0xadfad0) (BuildId: 803b2b7f59beb03d7849fb8294a8e2145dd4aa27) While it is somewhat awkward that the maintenance processes survive tests in the first place, it is totally expected that reftables should work alright with concurrent writers. Seemingly they don't. The only underlying resource that we need to care about in this context is the reftable reader, which is responsible for reading a single table from disk. These readers get discarded immediately (unless reused) when calling `reftable_stack_reload()`, which is wrong. We can only close them once we know that there are no iterators using them anymore. Prepare for a fix by converting the reftable readers to be refcounted. Reported-by: Jeff King <peff@peff.net> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is a stub, but it needs to be fleshed out.
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