FPMaxNormal should be returned instead of FPInfinity vcvt[t|b] instructions (to half precision) when roundingMode is round-to-zero. #14

twocode · 2014-08-26T06:45:53Z

The inconsistency with real device has existed since time ago. ARMv8 has enabled double-precision to half-precision - vcvt[t|b].f16.f64
also exposes such bug.

According to Page.5020 (DDI0487A), in FPRound():
// Deal with overflow and generate result.
if N != 16 || fpcr.AHP == '0' then // Single, double or IEEE half precision
if biased_exp >= 2^E - 1 then
result = if overflow_to_inf then FPInfinity(sign) else FPMaxNormal(sign);
FPProcessException(FPExc_Overflow, fpcr);
error = 1.0; // Ensure that an Inexact exception occurs
else
result = sign : biased_expN-F-2:0 : int_mantF-1:0;

When round-to-zero, overflow_to_inf is FALSE, FPMaxNormal should be returned.

…ctions (to half precision) when roundingMode is round-to-zero. The inconsistency with real device has existed since time ago. ARMv8 has enabled double-precision to half-precision - vcvt[t|b].f16.f64 also exposes such bug. According to Page.5020 (DDI0487A), in FPRound(): // Deal with overflow and generate result. if N != 16 || fpcr.AHP == '0' then // Single, double or IEEE half precision if biased_exp >= 2^E - 1 then result = if overflow_to_inf then FPInfinity(sign) else FPMaxNormal(sign); FPProcessException(FPExc_Overflow, fpcr); error = 1.0; // Ensure that an Inexact exception occurs else result = sign : biased_exp<N-F-2:0> : int_mant<F-1:0>; When round-to-zero, overflow_to_inf is FALSE, FPMaxNormal should be returned.

twocode · 2014-08-26T07:34:03Z

Typo from other local branches.

PRIP3 Hardware page Table Walker

While I was testing multi-threaded TCG I discovered once consequence of using locking around memory_region_dispatch is that virt-io transactions could dead lock trying to grab the main mutex. This is due to the virt-io driver writing data back into the system memory: #0 0x00007ffff119dcc9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56 qemu#1 0x00007ffff11a10d8 in __GI_abort () at abort.c:89 qemu#2 0x00005555555f9b24 in error_exit (err=<optimised out>, msg=msg@entry=0x5555559f3710 <__func__.6011> "qemu_mutex_lock") at util/qemu-thread-posix.c:48 qemu#3 0x000055555594d630 in qemu_mutex_lock (mutex=mutex@entry=0x555555e62e60 <qemu_global_mutex>) at util/qemu-thread-posix.c:79 qemu#4 0x0000555555631a84 in qemu_mutex_lock_iothread () at /home/alex/lsrc/qemu/qemu.git/cpus.c:1128 qemu#5 0x000055555560dd1a in stw_phys_internal (endian=DEVICE_LITTLE_ENDIAN, val=1, addr=<optimised out>, as=0x555555e08060 <address_space_memory>) at /home/alex/lsrc/qemu/qemu.git/exec.c:3010 qemu#6 stw_le_phys (as=as@entry=0x555555e08060 <address_space_memory>, addr=<optimised out>, val=1) at /home/alex/lsrc/qemu/qemu.git/exec.c:3024 qemu#7 0x0000555555696ae5 in virtio_stw_phys (vdev=<optimised out>, value=<optimised out>, pa=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/include/hw/virtio/virtio-access.h:61 qemu#8 vring_avail_event (vq=0x55555648dc00, vq=0x55555648dc00, vq=0x55555648dc00, val=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/hw/virtio/virtio.c:214 qemu#9 virtqueue_pop (vq=0x55555648dc00, elem=elem@entry=0x7fff1403fd98) at /home/alex/lsrc/qemu/qemu.git/hw/virtio/virtio.c:472 qemu#10 0x0000555555653cd1 in virtio_blk_get_request (s=0x555556486830) at /home/alex/lsrc/qemu/qemu.git/hw/block/virtio-blk.c:122 qemu#11 virtio_blk_handle_output (vdev=<optimised out>, vq=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/hw/block/virtio-blk.c:446 qemu#12 0x00005555556414e1 in access_with_adjusted_size (addr=addr@entry=80, value=value@entry=0x7fffa93052b0, size=size@entry=4, access_size_min=<optimised out>, access_size_max=<optimised out>, access=0x5555556413e0 <memory_region_write_accessor>, mr=0x555556b80388) at /home/alex/lsrc/qemu/qemu.git/memory.c:461 qemu#13 0x00005555556471b7 in memory_region_dispatch_write (size=4, data=0, addr=80, mr=0x555556b80388) at /home/alex/lsrc/qemu/qemu.git/memory.c:1103 qemu#14 io_mem_write (mr=mr@entry=0x555556b80388, addr=80, val=<optimised out>, size=size@entry=4) at /home/alex/lsrc/qemu/qemu.git/memory.c:2003 qemu#15 0x000055555560ad6b in address_space_rw_internal (as=<optimised out>, addr=167788112, buf=buf@entry=0x7fffa9305380 "", len=4, is_write=is_write@entry=true, unlocked=<optimised out>, unlocked@entry=false) at /home/alex/lsrc/qemu/qemu.git/exec.c:2318 qemu#16 0x000055555560aea8 in address_space_rw (is_write=true, len=<optimised out>, buf=0x7fffa9305380 "", addr=<optimised out>, as=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/exec.c:2392 qemu#17 address_space_write (len=<optimised out>, buf=0x7fffa9305380 "", addr=<optimised out>, as=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/exec.c:2404 qemu#18 subpage_write (opaque=<optimised out>, addr=<optimised out>, value=<optimised out>, len=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/exec.c:1963 qemu#19 0x00005555556414e1 in access_with_adjusted_size (addr=addr@entry=592, value=value@entry=0x7fffa9305420, size=size@entry=4, access_size_min=<optimised out>, access_size_max=<optimised out>, access=0x5555556413e0 <memory_region_write_accessor>, mr=0x555556bfca20) at /home/alex/lsrc/qemu/qemu.git/memory.c:461 qemu#20 0x00005555556471b7 in memory_region_dispatch_write (size=4, data=0, addr=592, mr=0x555556bfca20) at /home/alex/lsrc/qemu/qemu.git/memory.c:1103 qemu#21 io_mem_write (mr=mr@entry=0x555556bfca20, addr=addr@entry=592, val=val@entry=0, size=size@entry=4) at /home/alex/lsrc/qemu/qemu.git/memory.c:2003 qemu#22 0x000055555564ce16 in io_writel (retaddr=140736492182797, addr=4027616848, val=0, physaddr=592, env=0x55555649e9b0) at /home/alex/lsrc/qemu/qemu.git/softmmu_template.h:386 qemu#23 helper_le_stl_mmu (env=0x55555649e9b0, addr=<optimised out>, val=0, mmu_idx=<optimised out>, retaddr=140736492182797) at /home/alex/lsrc/qemu/qemu.git/softmmu_template.h:426 qemu#24 0x00007fffc49f9d0f in code_gen_buffer () qemu#25 0x00005555556109dc in cpu_tb_exec (tb_ptr=0x7fffc49f9c60 <code_gen_buffer+8371296> "A\213n\374\205\355\017\205\233\001", cpu=0x555556496750) at /home/alex/lsrc/qemu/qemu.git/cpu-exec.c:179 qemu#26 cpu_arm_exec (env=env@entry=0x55555649e9b0) at /home/alex/lsrc/qemu/qemu.git/cpu-exec.c:524 qemu#27 0x0000555555630f28 in tcg_cpu_exec (env=0x55555649e9b0) at /home/alex/lsrc/qemu/qemu.git/cpus.c:1344 qemu#28 tcg_exec_all (cpu=0x555556496750) at /home/alex/lsrc/qemu/qemu.git/cpus.c:1392 qemu#29 qemu_tcg_cpu_thread_fn (arg=0x555556496750) at /home/alex/lsrc/qemu/qemu.git/cpus.c:1037 qemu#30 0x00007ffff1534182 in start_thread (arg=0x7fffa9306700) at pthread_create.c:312 qemu#31 0x00007ffff126147d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 The fix in this patch makes the global/iothread mutex recursive (only if called from the same thread-id). As other threads are still blocked memory is still consistent all the way through. This seems neater than having to do a trylock each time. Tested-by: Alex Bennée <alex.bennee@linaro.org>

While I was testing multi-threaded TCG I discovered once consequence of using locking around memory_region_dispatch is that virt-io transactions could dead lock trying to grab the main mutex. This is due to the virt-io driver writing data back into the system memory: #0 0x00007ffff119dcc9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56 qemu#1 0x00007ffff11a10d8 in __GI_abort () at abort.c:89 qemu#2 0x00005555555f9b24 in error_exit (err=<optimised out>, msg=msg@entry=0x5555559f3710 <__func__.6011> "qemu_mutex_lock") at util/qemu-thread-posix.c:48 qemu#3 0x000055555594d630 in qemu_mutex_lock (mutex=mutex@entry=0x555555e62e60 <qemu_global_mutex>) at util/qemu-thread-posix.c:79 qemu#4 0x0000555555631a84 in qemu_mutex_lock_iothread () at /home/alex/lsrc/qemu/qemu.git/cpus.c:1128 qemu#5 0x000055555560dd1a in stw_phys_internal (endian=DEVICE_LITTLE_ENDIAN, val=1, addr=<optimised out>, as=0x555555e08060 <address_space_memory>) at /home/alex/lsrc/qemu/qemu.git/exec.c:3010 qemu#6 stw_le_phys (as=as@entry=0x555555e08060 <address_space_memory>, addr=<optimised out>, val=1) at /home/alex/lsrc/qemu/qemu.git/exec.c:3024 qemu#7 0x0000555555696ae5 in virtio_stw_phys (vdev=<optimised out>, value=<optimised out>, pa=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/include/hw/virtio/virtio-access.h:61 qemu#8 vring_avail_event (vq=0x55555648dc00, vq=0x55555648dc00, vq=0x55555648dc00, val=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/hw/virtio/virtio.c:214 qemu#9 virtqueue_pop (vq=0x55555648dc00, elem=elem@entry=0x7fff1403fd98) at /home/alex/lsrc/qemu/qemu.git/hw/virtio/virtio.c:472 qemu#10 0x0000555555653cd1 in virtio_blk_get_request (s=0x555556486830) at /home/alex/lsrc/qemu/qemu.git/hw/block/virtio-blk.c:122 qemu#11 virtio_blk_handle_output (vdev=<optimised out>, vq=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/hw/block/virtio-blk.c:446 qemu#12 0x00005555556414e1 in access_with_adjusted_size (addr=addr@entry=80, value=value@entry=0x7fffa93052b0, size=size@entry=4, access_size_min=<optimised out>, access_size_max=<optimised out>, access=0x5555556413e0 <memory_region_write_accessor>, mr=0x555556b80388) at /home/alex/lsrc/qemu/qemu.git/memory.c:461 qemu#13 0x00005555556471b7 in memory_region_dispatch_write (size=4, data=0, addr=80, mr=0x555556b80388) at /home/alex/lsrc/qemu/qemu.git/memory.c:1103 qemu#14 io_mem_write (mr=mr@entry=0x555556b80388, addr=80, val=<optimised out>, size=size@entry=4) at /home/alex/lsrc/qemu/qemu.git/memory.c:2003 qemu#15 0x000055555560ad6b in address_space_rw_internal (as=<optimised out>, addr=167788112, buf=buf@entry=0x7fffa9305380 "", len=4, is_write=is_write@entry=true, unlocked=<optimised out>, unlocked@entry=false) at /home/alex/lsrc/qemu/qemu.git/exec.c:2318 qemu#16 0x000055555560aea8 in address_space_rw (is_write=true, len=<optimised out>, buf=0x7fffa9305380 "", addr=<optimised out>, as=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/exec.c:2392 qemu#17 address_space_write (len=<optimised out>, buf=0x7fffa9305380 "", addr=<optimised out>, as=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/exec.c:2404 qemu#18 subpage_write (opaque=<optimised out>, addr=<optimised out>, value=<optimised out>, len=<optimised out>) at /home/alex/lsrc/qemu/qemu.git/exec.c:1963 qemu#19 0x00005555556414e1 in access_with_adjusted_size (addr=addr@entry=592, value=value@entry=0x7fffa9305420, size=size@entry=4, access_size_min=<optimised out>, access_size_max=<optimised out>, access=0x5555556413e0 <memory_region_write_accessor>, mr=0x555556bfca20) at /home/alex/lsrc/qemu/qemu.git/memory.c:461 qemu#20 0x00005555556471b7 in memory_region_dispatch_write (size=4, data=0, addr=592, mr=0x555556bfca20) at /home/alex/lsrc/qemu/qemu.git/memory.c:1103 qemu#21 io_mem_write (mr=mr@entry=0x555556bfca20, addr=addr@entry=592, val=val@entry=0, size=size@entry=4) at /home/alex/lsrc/qemu/qemu.git/memory.c:2003 qemu#22 0x000055555564ce16 in io_writel (retaddr=140736492182797, addr=4027616848, val=0, physaddr=592, env=0x55555649e9b0) at /home/alex/lsrc/qemu/qemu.git/softmmu_template.h:386 qemu#23 helper_le_stl_mmu (env=0x55555649e9b0, addr=<optimised out>, val=0, mmu_idx=<optimised out>, retaddr=140736492182797) at /home/alex/lsrc/qemu/qemu.git/softmmu_template.h:426 qemu#24 0x00007fffc49f9d0f in code_gen_buffer () qemu#25 0x00005555556109dc in cpu_tb_exec (tb_ptr=0x7fffc49f9c60 <code_gen_buffer+8371296> "A\213n\374\205\355\017\205\233\001", cpu=0x555556496750) at /home/alex/lsrc/qemu/qemu.git/cpu-exec.c:179 qemu#26 cpu_arm_exec (env=env@entry=0x55555649e9b0) at /home/alex/lsrc/qemu/qemu.git/cpu-exec.c:524 qemu#27 0x0000555555630f28 in tcg_cpu_exec (env=0x55555649e9b0) at /home/alex/lsrc/qemu/qemu.git/cpus.c:1344 qemu#28 tcg_exec_all (cpu=0x555556496750) at /home/alex/lsrc/qemu/qemu.git/cpus.c:1392 qemu#29 qemu_tcg_cpu_thread_fn (arg=0x555556496750) at /home/alex/lsrc/qemu/qemu.git/cpus.c:1037 qemu#30 0x00007ffff1534182 in start_thread (arg=0x7fffa9306700) at pthread_create.c:312 qemu#31 0x00007ffff126147d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 The fix in this patch makes the global/iothread mutex recursive. However as condition variables are involved we deal with this in our own code by tracking the number of locks held by the thread. This seems neater than having to do a trylock each time. Tested-by: Alex Bennée <alex.bennee@linaro.org> --- v2 - don't actually use pthread recursion mechanism - convert rest of qemu_mutex_lock(&global_global_mutex) to iothread - emulate recursion with thread local tracking

"name" is freed after visiting options, instead use the first NetClientState name. Adds a few assert() for clarifying and checking some impossible states. READ of size 1 at 0x602000000990 thread T0 #0 0x7f6b251c570c (/lib64/libasan.so.2+0x4770c) #1 0x5566dc380600 in qemu_find_net_clients_except net/net.c:824 #2 0x5566dc39bac7 in net_vhost_user_event net/vhost-user.c:193 #3 0x5566dbee862a in qemu_chr_be_event /home/elmarco/src/qemu/qemu-char.c:201 #4 0x5566dbef2890 in tcp_chr_disconnect /home/elmarco/src/qemu/qemu-char.c:2790 #5 0x5566dbef2d0b in tcp_chr_sync_read /home/elmarco/src/qemu/qemu-char.c:2835 #6 0x5566dbee8a99 in qemu_chr_fe_read_all /home/elmarco/src/qemu/qemu-char.c:295 #7 0x5566dc39b964 in net_vhost_user_watch net/vhost-user.c:180 #8 0x5566dc5a06c7 in qio_channel_fd_source_dispatch io/channel-watch.c:70 #9 0x7f6b1aa2ab87 in g_main_dispatch /home/elmarco/src/gnome/glib/glib/gmain.c:3154 #10 0x7f6b1aa2b9cb in g_main_context_dispatch /home/elmarco/src/gnome/glib/glib/gmain.c:3769 #11 0x5566dc475ed4 in glib_pollfds_poll /home/elmarco/src/qemu/main-loop.c:212 #12 0x5566dc476029 in os_host_main_loop_wait /home/elmarco/src/qemu/main-loop.c:257 #13 0x5566dc476165 in main_loop_wait /home/elmarco/src/qemu/main-loop.c:505 #14 0x5566dbf08d31 in main_loop /home/elmarco/src/qemu/vl.c:1932 #15 0x5566dbf16783 in main /home/elmarco/src/qemu/vl.c:4646 #16 0x7f6b180bb57f in __libc_start_main (/lib64/libc.so.6+0x2057f) #17 0x5566dbbf5348 in _start (/home/elmarco/src/qemu/x86_64-softmmu/qemu-system-x86_64+0x3f9348) 0x602000000990 is located 0 bytes inside of 5-byte region [0x602000000990,0x602000000995) freed by thread T0 here: #0 0x7f6b2521666a in __interceptor_free (/lib64/libasan.so.2+0x9866a) #1 0x7f6b1aa332a4 in g_free /home/elmarco/src/gnome/glib/glib/gmem.c:189 #2 0x5566dc5f416f in qapi_dealloc_type_str qapi/qapi-dealloc-visitor.c:134 #3 0x5566dc5f3268 in visit_type_str qapi/qapi-visit-core.c:196 #4 0x5566dc5ced58 in visit_type_Netdev_fields /home/elmarco/src/qemu/qapi-visit.c:5936 #5 0x5566dc5cef71 in visit_type_Netdev /home/elmarco/src/qemu/qapi-visit.c:5960 #6 0x5566dc381a8d in net_visit net/net.c:1049 #7 0x5566dc381c37 in net_client_init net/net.c:1076 #8 0x5566dc3839e2 in net_init_netdev net/net.c:1473 #9 0x5566dc63cc0a in qemu_opts_foreach util/qemu-option.c:1112 #10 0x5566dc383b36 in net_init_clients net/net.c:1499 #11 0x5566dbf15d86 in main /home/elmarco/src/qemu/vl.c:4397 #12 0x7f6b180bb57f in __libc_start_main (/lib64/libc.so.6+0x2057f) Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Revamp the excluvise operation mechanism a bit, taking into account t…

Back in the 2.3.0 release we declared qcow[2] encryption as deprecated, warning people that it would be removed in a future release. commit a1f688f Author: Markus Armbruster <armbru@redhat.com> Date: Fri Mar 13 21:09:40 2015 +0100 block: Deprecate QCOW/QCOW2 encryption The code still exists today, but by a (happy?) accident we entirely broke the ability to use qcow[2] encryption in the system emulators in the 2.4.0 release due to commit 8336aaf Author: Daniel P. Berrange <berrange@redhat.com> Date: Tue May 12 17:09:18 2015 +0100 qcow2/qcow: protect against uninitialized encryption key This commit was designed to prevent future coding bugs which might cause QEMU to read/write data on an encrypted block device in plain text mode before a decryption key is set. It turns out this preventative measure was a little too good, because we already had a long standing bug where QEMU read encrypted data in plain text mode during system emulator startup, in order to guess disk geometry: Thread 10 (Thread 0x7fffd3fff700 (LWP 30373)): #0 0x00007fffe90b1a28 in raise () at /lib64/libc.so.6 #1 0x00007fffe90b362a in abort () at /lib64/libc.so.6 #2 0x00007fffe90aa227 in __assert_fail_base () at /lib64/libc.so.6 #3 0x00007fffe90aa2d2 in () at /lib64/libc.so.6 #4 0x000055555587ae19 in qcow2_co_readv (bs=0x5555562accb0, sector_num=0, remaining_sectors=1, qiov=0x7fffffffd260) at block/qcow2.c:1229 #5 0x000055555589b60d in bdrv_aligned_preadv (bs=bs@entry=0x5555562accb0, req=req@entry=0x7fffd3ffea50, offset=offset@entry=0, bytes=bytes@entry=512, align=align@entry=512, qiov=qiov@entry=0x7fffffffd260, flags=0) at block/io.c:908 #6 0x000055555589b8bc in bdrv_co_do_preadv (bs=0x5555562accb0, offset=0, bytes=512, qiov=0x7fffffffd260, flags=<optimized out>) at block/io.c:999 #7 0x000055555589c375 in bdrv_rw_co_entry (opaque=0x7fffffffd210) at block/io.c:544 #8 0x000055555586933b in coroutine_thread (opaque=0x555557876310) at coroutine-gthread.c:134 #9 0x00007ffff64e1835 in g_thread_proxy (data=0x5555562b5590) at gthread.c:778 #10 0x00007ffff6bb760a in start_thread () at /lib64/libpthread.so.0 #11 0x00007fffe917f59d in clone () at /lib64/libc.so.6 Thread 1 (Thread 0x7ffff7ecab40 (LWP 30343)): #0 0x00007fffe91797a9 in syscall () at /lib64/libc.so.6 #1 0x00007ffff64ff87f in g_cond_wait (cond=cond@entry=0x555555e085f0 <coroutine_cond>, mutex=mutex@entry=0x555555e08600 <coroutine_lock>) at gthread-posix.c:1397 #2 0x00005555558692c3 in qemu_coroutine_switch (co=<optimized out>) at coroutine-gthread.c:117 #3 0x00005555558692c3 in qemu_coroutine_switch (from_=0x5555562b5e30, to_=to_@entry=0x555557876310, action=action@entry=COROUTINE_ENTER) at coroutine-gthread.c:175 #4 0x0000555555868a90 in qemu_coroutine_enter (co=0x555557876310, opaque=0x0) at qemu-coroutine.c:116 #5 0x0000555555859b84 in thread_pool_completion_bh (opaque=0x7fffd40010e0) at thread-pool.c:187 #6 0x0000555555859514 in aio_bh_poll (ctx=ctx@entry=0x5555562953b0) at async.c:85 #7 0x0000555555864d10 in aio_dispatch (ctx=ctx@entry=0x5555562953b0) at aio-posix.c:135 #8 0x0000555555864f75 in aio_poll (ctx=ctx@entry=0x5555562953b0, blocking=blocking@entry=true) at aio-posix.c:291 #9 0x000055555589c40d in bdrv_prwv_co (bs=bs@entry=0x5555562accb0, offset=offset@entry=0, qiov=qiov@entry=0x7fffffffd260, is_write=is_write@entry=false, flags=flags@entry=(unknown: 0)) at block/io.c:591 #10 0x000055555589c503 in bdrv_rw_co (bs=bs@entry=0x5555562accb0, sector_num=sector_num@entry=0, buf=buf@entry=0x7fffffffd2e0 "\321,", nb_sectors=nb_sectors@entry=21845, is_write=is_write@entry=false, flags=flags@entry=(unknown: 0)) at block/io.c:614 #11 0x000055555589c562 in bdrv_read_unthrottled (nb_sectors=21845, buf=0x7fffffffd2e0 "\321,", sector_num=0, bs=0x5555562accb0) at block/io.c:622 #12 0x000055555589c562 in bdrv_read_unthrottled (bs=0x5555562accb0, sector_num=sector_num@entry=0, buf=buf@entry=0x7fffffffd2e0 "\321,", nb_sectors=nb_sectors@entry=21845) at block/io.c:634 nb_sectors@entry=1) at block/block-backend.c:504 #14 0x0000555555752e9f in guess_disk_lchs (blk=blk@entry=0x5555562a5290, pcylinders=pcylinders@entry=0x7fffffffd52c, pheads=pheads@entry=0x7fffffffd530, psectors=psectors@entry=0x7fffffffd534) at hw/block/hd-geometry.c:68 #15 0x0000555555752ff7 in hd_geometry_guess (blk=0x5555562a5290, pcyls=pcyls@entry=0x555557875d1c, pheads=pheads@entry=0x555557875d20, psecs=psecs@entry=0x555557875d24, ptrans=ptrans@entry=0x555557875d28) at hw/block/hd-geometry.c:133 #16 0x0000555555752b87 in blkconf_geometry (conf=conf@entry=0x555557875d00, ptrans=ptrans@entry=0x555557875d28, cyls_max=cyls_max@entry=65536, heads_max=heads_max@entry=16, secs_max=secs_max@entry=255, errp=errp@entry=0x7fffffffd5e0) at hw/block/block.c:71 #17 0x0000555555799bc4 in ide_dev_initfn (dev=0x555557875c80, kind=IDE_HD) at hw/ide/qdev.c:174 #18 0x0000555555768394 in device_realize (dev=0x555557875c80, errp=0x7fffffffd640) at hw/core/qdev.c:247 #19 0x0000555555769a81 in device_set_realized (obj=0x555557875c80, value=<optimized out>, errp=0x7fffffffd730) at hw/core/qdev.c:1058 #20 0x00005555558240ce in property_set_bool (obj=0x555557875c80, v=<optimized out>, opaque=0x555557875de0, name=<optimized out>, errp=0x7fffffffd730) at qom/object.c:1514 #21 0x0000555555826c87 in object_property_set_qobject (obj=obj@entry=0x555557875c80, value=value@entry=0x55555784bcb0, name=name@entry=0x55555591cb3d "realized", errp=errp@entry=0x7fffffffd730) at qom/qom-qobject.c:24 #22 0x0000555555825760 in object_property_set_bool (obj=obj@entry=0x555557875c80, value=value@entry=true, name=name@entry=0x55555591cb3d "realized", errp=errp@entry=0x7fffffffd730) at qom/object.c:905 #23 0x000055555576897b in qdev_init_nofail (dev=dev@entry=0x555557875c80) at hw/core/qdev.c:380 #24 0x0000555555799ead in ide_create_drive (bus=bus@entry=0x555557629630, unit=unit@entry=0, drive=0x5555562b77e0) at hw/ide/qdev.c:122 #25 0x000055555579a746 in pci_ide_create_devs (dev=dev@entry=0x555557628db0, hd_table=hd_table@entry=0x7fffffffd830) at hw/ide/pci.c:440 #26 0x000055555579b165 in pci_piix3_ide_init (bus=<optimized out>, hd_table=0x7fffffffd830, devfn=<optimized out>) at hw/ide/piix.c:218 #27 0x000055555568ca55 in pc_init1 (machine=0x5555562960a0, pci_enabled=1, kvmclock_enabled=<optimized out>) at /home/berrange/src/virt/qemu/hw/i386/pc_piix.c:256 #28 0x0000555555603ab2 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4249 So the safety net is correctly preventing QEMU reading cipher text as if it were plain text, during startup and aborting QEMU to avoid bad usage of this data. For added fun this bug only happens if the encrypted qcow2 file happens to have data written to the first cluster, otherwise the cluster won't be allocated and so qcow2 would not try the decryption routines at all, just return all 0's. That no one even noticed, let alone reported, this bug that has shipped in 2.4.0, 2.5.0 and 2.6.0 shows that the number of actual users of encrypted qcow2 is approximately zero. So rather than fix the crash, and backport it to stable releases, just go ahead with what we have warned users about and disable any use of qcow2 encryption in the system emulators. qemu-img/qemu-io/qemu-nbd are still able to access qcow2 encrypted images for the sake of data conversion. In the future, qcow2 will gain support for the alternative luks format, but when this happens it'll be using the '-object secret' infrastructure for getting keys, which avoids this problematic scenario entirely. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

ahci-test /x86_64/ahci/io/dma/lba28/retry triggers the following leak: Direct leak of 16 byte(s) in 1 object(s) allocated from: #0 0x7fc4b2a25e20 in malloc (/lib64/libasan.so.3+0xc6e20) qemu#1 0x7fc4993bce58 in g_malloc (/lib64/libglib-2.0.so.0+0x4ee58) qemu#2 0x556a187d4b34 in ahci_populate_sglist hw/ide/ahci.c:896 qemu#3 0x556a187d8237 in ahci_dma_prepare_buf hw/ide/ahci.c:1367 qemu#4 0x556a187b5a1a in ide_dma_cb hw/ide/core.c:844 qemu#5 0x556a187d7eec in ahci_start_dma hw/ide/ahci.c:1333 qemu#6 0x556a187b650b in ide_start_dma hw/ide/core.c:921 qemu#7 0x556a187b61e6 in ide_sector_start_dma hw/ide/core.c:911 qemu#8 0x556a187b9e26 in cmd_write_dma hw/ide/core.c:1486 qemu#9 0x556a187bd519 in ide_exec_cmd hw/ide/core.c:2027 qemu#10 0x556a187d71c5 in handle_reg_h2d_fis hw/ide/ahci.c:1204 qemu#11 0x556a187d7681 in handle_cmd hw/ide/ahci.c:1254 qemu#12 0x556a187d168a in check_cmd hw/ide/ahci.c:510 qemu#13 0x556a187d0afc in ahci_port_write hw/ide/ahci.c:314 qemu#14 0x556a187d105d in ahci_mem_write hw/ide/ahci.c:435 qemu#15 0x556a1831d959 in memory_region_write_accessor /home/elmarco/src/qemu/memory.c:525 qemu#16 0x556a1831dc35 in access_with_adjusted_size /home/elmarco/src/qemu/memory.c:591 qemu#17 0x556a18323ce3 in memory_region_dispatch_write /home/elmarco/src/qemu/memory.c:1262 qemu#18 0x556a1828cf67 in address_space_write_continue /home/elmarco/src/qemu/exec.c:2578 qemu#19 0x556a1828d20b in address_space_write /home/elmarco/src/qemu/exec.c:2635 qemu#20 0x556a1828d92b in address_space_rw /home/elmarco/src/qemu/exec.c:2737 qemu#21 0x556a1828daf7 in cpu_physical_memory_rw /home/elmarco/src/qemu/exec.c:2746 qemu#22 0x556a183068d3 in cpu_physical_memory_write /home/elmarco/src/qemu/include/exec/cpu-common.h:72 qemu#23 0x556a18308194 in qtest_process_command /home/elmarco/src/qemu/qtest.c:382 qemu#24 0x556a18309999 in qtest_process_inbuf /home/elmarco/src/qemu/qtest.c:573 qemu#25 0x556a18309a4a in qtest_read /home/elmarco/src/qemu/qtest.c:585 qemu#26 0x556a18598b85 in qemu_chr_be_write_impl /home/elmarco/src/qemu/qemu-char.c:387 qemu#27 0x556a18598c52 in qemu_chr_be_write /home/elmarco/src/qemu/qemu-char.c:399 qemu#28 0x556a185a2afa in tcp_chr_read /home/elmarco/src/qemu/qemu-char.c:2902 qemu#29 0x556a18cbaf52 in qio_channel_fd_source_dispatch io/channel-watch.c:84 Follow John Snow recommendation: Everywhere else ncq_err is used, it is accompanied by a list cleanup except for ncq_cb, which is the case you are fixing here. Move the sglist destruction inside of ncq_err and then delete it from the other two locations to keep it tidy. Call dma_buf_commit in ide_dma_cb after the early return. Though, this is also a little wonky because this routine does more than clear the list, but it is at the moment the centralized "we're done with the sglist" function and none of the other side effects that occur in dma_buf_commit will interfere with the reset that occurs from ide_restart_bh, I think Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Since aa5cb7f, the chardevs are being cleaned up when leaving qemu. However, the monitor has still references to them, which may lead to crashes when running atexit() and trying to send monitor events: #0 0x00007fffdb18f6f5 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54 qemu#1 0x00007fffdb1912fa in __GI_abort () at abort.c:89 qemu#2 0x0000555555c263e7 in error_exit (err=22, msg=0x555555d47980 <__func__.13537> "qemu_mutex_lock") at util/qemu-thread-posix.c:39 qemu#3 0x0000555555c26488 in qemu_mutex_lock (mutex=0x5555567a2420) at util/qemu-thread-posix.c:66 qemu#4 0x00005555558c52db in qemu_chr_fe_write (s=0x5555567a2420, buf=0x55555740dc40 "{\"timestamp\": {\"seconds\": 1470041716, \"microseconds\": 989699}, \"event\": \"SPICE_DISCONNECTED\", \"data\": {\"server\": {\"port\": \"5900\", \"family\": \"ipv4\", \"host\": \"127.0.0.1\"}, \"client\": {\"port\": \"40272\", \"f"..., len=240) at qemu-char.c:280 qemu#5 0x0000555555787cad in monitor_flush_locked (mon=0x5555567bd9e0) at /home/elmarco/src/qemu/monitor.c:311 qemu#6 0x0000555555787e46 in monitor_puts (mon=0x5555567bd9e0, str=0x5555567a44ef "") at /home/elmarco/src/qemu/monitor.c:353 qemu#7 0x00005555557880fe in monitor_json_emitter (mon=0x5555567bd9e0, data=0x5555567c73a0) at /home/elmarco/src/qemu/monitor.c:401 qemu#8 0x00005555557882d2 in monitor_qapi_event_emit (event=QAPI_EVENT_SPICE_DISCONNECTED, qdict=0x5555567c73a0) at /home/elmarco/src/qemu/monitor.c:472 qemu#9 0x000055555578838f in monitor_qapi_event_queue (event=QAPI_EVENT_SPICE_DISCONNECTED, qdict=0x5555567c73a0, errp=0x7fffffffca88) at /home/elmarco/src/qemu/monitor.c:497 qemu#10 0x0000555555c15541 in qapi_event_send_spice_disconnected (server=0x5555571139d0, client=0x5555570d0db0, errp=0x5555566c0428 <error_abort>) at qapi-event.c:1038 qemu#11 0x0000555555b11bc6 in channel_event (event=3, info=0x5555570d6c00) at ui/spice-core.c:248 qemu#12 0x00007fffdcc9983a in adapter_channel_event (event=3, info=0x5555570d6c00) at reds.c:120 qemu#13 0x00007fffdcc99a25 in reds_handle_channel_event (reds=0x5555567a9d60, event=3, info=0x5555570d6c00) at reds.c:324 qemu#14 0x00007fffdcc7d4c4 in main_dispatcher_self_handle_channel_event (self=0x5555567b28b0, event=3, info=0x5555570d6c00) at main-dispatcher.c:175 qemu#15 0x00007fffdcc7d5b1 in main_dispatcher_channel_event (self=0x5555567b28b0, event=3, info=0x5555570d6c00) at main-dispatcher.c:194 qemu#16 0x00007fffdcca7674 in reds_stream_push_channel_event (s=0x5555570d9910, event=3) at reds-stream.c:354 qemu#17 0x00007fffdcca749b in reds_stream_free (s=0x5555570d9910) at reds-stream.c:323 qemu#18 0x00007fffdccb5dad in snd_disconnect_channel (channel=0x5555576a89a0) at sound.c:229 qemu#19 0x00007fffdccb9e57 in snd_detach_common (worker=0x555557739720) at sound.c:1589 qemu#20 0x00007fffdccb9f0e in snd_detach_playback (sin=0x5555569fe3f8) at sound.c:1602 qemu#21 0x00007fffdcca3373 in spice_server_remove_interface (sin=0x5555569fe3f8) at reds.c:3387 qemu#22 0x00005555558ff6e2 in line_out_fini (hw=0x5555569fe370) at audio/spiceaudio.c:152 qemu#23 0x00005555558f909e in audio_atexit () at audio/audio.c:1754 qemu#24 0x00007fffdb1941e8 in __run_exit_handlers (status=0, listp=0x7fffdb5175d8 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:82 qemu#25 0x00007fffdb194235 in __GI_exit (status=<optimized out>) at exit.c:104 qemu#26 0x00007fffdb17b738 in __libc_start_main (main=0x5555558d7874 <main>, argc=67, argv=0x7fffffffcf48, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffcf38) at ../csu/libc-start.c:323 Add a monitor_cleanup() functions to remove all the monitors before cleaning up the chardev. Note that we are "losing" some events that used to be sent during atexit(). Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

@entry

When VNC is started with '-vnc none' there will be no listener socket present. When we try to populate the VncServerInfo we'll crash accessing a NULL 'lsock' field. #0 qio_channel_socket_get_local_address (ioc=0x0, errp=errp@entry=0x7ffd5b8aa0f0) at io/channel-socket.c:33 qemu#1 0x00007f4b9a297d6f in vnc_init_basic_info_from_server_addr (errp=0x7ffd5b8aa0f0, info=0x7f4b9d425460, ioc=<optimized out>) at ui/vnc.c:146 qemu#2 vnc_server_info_get (vd=0x7f4b9e858000) at ui/vnc.c:223 qemu#3 0x00007f4b9a29d318 in vnc_qmp_event (vs=0x7f4b9ef82000, vs=0x7f4b9ef82000, event=QAPI_EVENT_VNC_CONNECTED) at ui/vnc.c:279 qemu#4 vnc_connect (vd=vd@entry=0x7f4b9e858000, sioc=sioc@entry=0x7f4b9e8b3a20, skipauth=skipauth@entry=true, websocket=websocket @entry=false) at ui/vnc.c:2994 qemu#5 0x00007f4b9a29e8c8 in vnc_display_add_client (id=<optimized out>, csock=<optimized out>, skipauth=<optimized out>) at ui/v nc.c:3825 qemu#6 0x00007f4b9a18d8a1 in qmp_marshal_add_client (args=<optimized out>, ret=<optimized out>, errp=0x7ffd5b8aa230) at qmp-marsh al.c:123 qemu#7 0x00007f4b9a0b53f5 in handle_qmp_command (parser=<optimized out>, tokens=<optimized out>) at /usr/src/debug/qemu-2.6.0/mon itor.c:3922 qemu#8 0x00007f4b9a348580 in json_message_process_token (lexer=0x7f4b9c78dfe8, input=0x7f4b9c7350e0, type=JSON_RCURLY, x=111, y=5 9) at qobject/json-streamer.c:94 qemu#9 0x00007f4b9a35cfeb in json_lexer_feed_char (lexer=lexer@entry=0x7f4b9c78dfe8, ch=125 '}', flush=flush@entry=false) at qobj ect/json-lexer.c:310 qemu#10 0x00007f4b9a35d0ae in json_lexer_feed (lexer=0x7f4b9c78dfe8, buffer=<optimized out>, size=<optimized out>) at qobject/json -lexer.c:360 qemu#11 0x00007f4b9a348679 in json_message_parser_feed (parser=<optimized out>, buffer=<optimized out>, size=<optimized out>) at q object/json-streamer.c:114 qemu#12 0x00007f4b9a0b3a1b in monitor_qmp_read (opaque=<optimized out>, buf=<optimized out>, size=<optimized out>) at /usr/src/deb ug/qemu-2.6.0/monitor.c:3938 qemu#13 0x00007f4b9a186751 in tcp_chr_read (chan=<optimized out>, cond=<optimized out>, opaque=0x7f4b9c7add40) at qemu-char.c:2895 qemu#14 0x00007f4b92b5c79a in g_main_context_dispatch () from /lib64/libglib-2.0.so.0 qemu#15 0x00007f4b9a2bb0c0 in glib_pollfds_poll () at main-loop.c:213 qemu#16 os_host_main_loop_wait (timeout=<optimized out>) at main-loop.c:258 qemu#17 main_loop_wait (nonblocking=<optimized out>) at main-loop.c:506 qemu#18 0x00007f4b9a0835cf in main_loop () at vl.c:1934 qemu#19 main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4667 Do an upfront check for a NULL lsock and report an error to the caller, which matches behaviour from before commit 04d2529 Author: Daniel P. Berrange <berrange@redhat.com> Date: Fri Feb 27 16:20:57 2015 +0000 ui: convert VNC server to use QIOChannelSocket where getsockname() would be given a FD value -1 and thus report an error to the caller. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

The vnc_server_info_get will allocate the VncServerInfo struct and then call vnc_init_basic_info_from_server_addr to populate the basic fields. If this returns an error though, the qapi_free_VncServerInfo call will then crash because the VncServerInfo struct instance was not properly NULL-initialized and thus contains random stack garbage. #0 0x00007f1987c8e6f5 in raise () at /lib64/libc.so.6 qemu#1 0x00007f1987c902fa in abort () at /lib64/libc.so.6 qemu#2 0x00007f1987ccf600 in __libc_message () at /lib64/libc.so.6 qemu#3 0x00007f1987cd7d4a in _int_free () at /lib64/libc.so.6 qemu#4 0x00007f1987cdb2ac in free () at /lib64/libc.so.6 qemu#5 0x00007f198b654f6e in g_free () at /lib64/libglib-2.0.so.0 qemu#6 0x0000559193cdcf54 in visit_type_str (v=v@entry= 0x5591972f14b0, name=name@entry=0x559193de1e29 "host", obj=obj@entry=0x5591961dbfa0, errp=errp@entry=0x7fffd7899d80) at qapi/qapi-visit-core.c:255 qemu#7 0x0000559193cca8f3 in visit_type_VncBasicInfo_members (v=v@entry= 0x5591972f14b0, obj=obj@entry=0x5591961dbfa0, errp=errp@entry=0x7fffd7899dc0) at qapi-visit.c:12307 qemu#8 0x0000559193ccb523 in visit_type_VncServerInfo_members (v=v@entry= 0x5591972f14b0, obj=0x5591961dbfa0, errp=errp@entry=0x7fffd7899e00) at qapi-visit.c:12632 qemu#9 0x0000559193ccb60b in visit_type_VncServerInfo (v=v@entry= 0x5591972f14b0, name=name@entry=0x0, obj=obj@entry=0x7fffd7899e48, errp=errp@entry=0x0) at qapi-visit.c:12658 qemu#10 0x0000559193cb53d8 in qapi_free_VncServerInfo (obj=<optimized out>) at qapi-types.c:3970 qemu#11 0x0000559193c1e6ba in vnc_server_info_get (vd=0x7f1951498010) at ui/vnc.c:233 qemu#12 0x0000559193c24275 in vnc_connect (vs=0x559197b2f200, vs=0x559197b2f200, event=QAPI_EVENT_VNC_CONNECTED) at ui/vnc.c:284 qemu#13 0x0000559193c24275 in vnc_connect (vd=vd@entry=0x7f1951498010, sioc=sioc@entry=0x559196bf9c00, skipauth=skipauth@entry=tru e, websocket=websocket@entry=false) at ui/vnc.c:3039 qemu#14 0x0000559193c25806 in vnc_display_add_client (id=<optimized out>, csock=<optimized out>, skipauth=<optimized out>) at ui/vnc.c:3877 qemu#15 0x0000559193a90c28 in qmp_marshal_add_client (args=<optimized out>, ret=<optimized out>, errp=0x7fffd7899f90) at qmp-marshal.c:105 qemu#16 0x000055919399c2b7 in handle_qmp_command (parser=<optimized out>, tokens=<optimized out>) at /home/berrange/src/virt/qemu/monitor.c:3971 qemu#17 0x0000559193ce3307 in json_message_process_token (lexer=0x559194ab0838, input=0x559194a6d940, type=JSON_RCURLY, x=111, y=1 2) at qobject/json-streamer.c:105 qemu#18 0x0000559193cfa90d in json_lexer_feed_char (lexer=lexer@entry=0x559194ab0838, ch=125 '}', flush=flush@entry=false) at qobject/json-lexer.c:319 qemu#19 0x0000559193cfaa1e in json_lexer_feed (lexer=0x559194ab0838, buffer=<optimized out>, size=<optimized out>) at qobject/json-lexer.c:369 qemu#20 0x0000559193ce33c9 in json_message_parser_feed (parser=<optimized out>, buffer=<optimized out>, size=<optimized out>) at qobject/json-streamer.c:124 qemu#21 0x000055919399a85b in monitor_qmp_read (opaque=<optimized out>, buf=<optimized out>, size=<optimized out>) at /home/berrange/src/virt/qemu/monitor.c:3987 qemu#22 0x0000559193a87d00 in tcp_chr_read (chan=<optimized out>, cond=<optimized out>, opaque=0x559194a7d900) at qemu-char.c:2895 qemu#23 0x00007f198b64f703 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0 qemu#24 0x0000559193c484b3 in main_loop_wait () at main-loop.c:213 qemu#25 0x0000559193c484b3 in main_loop_wait (timeout=<optimized out>) at main-loop.c:258 qemu#26 0x0000559193c484b3 in main_loop_wait (nonblocking=<optimized out>) at main-loop.c:506 qemu#27 0x0000559193964c55 in main () at vl.c:1908 qemu#28 0x0000559193964c55 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4603 This was introduced in commit 98481bf Author: Eric Blake <eblake@redhat.com> Date: Mon Oct 26 16:34:45 2015 -0600 vnc: Hoist allocation of VncBasicInfo to callers which added error reporting for vnc_init_basic_info_from_server_addr but didn't change the g_malloc calls to g_malloc0. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

@entry

When VNC is started with '-vnc none' there will be no listener socket present. When we try to populate the VncServerInfo we'll crash accessing a NULL 'lsock' field. #0 qio_channel_socket_get_local_address (ioc=0x0, errp=errp@entry=0x7ffd5b8aa0f0) at io/channel-socket.c:33 #1 0x00007f4b9a297d6f in vnc_init_basic_info_from_server_addr (errp=0x7ffd5b8aa0f0, info=0x7f4b9d425460, ioc=<optimized out>) at ui/vnc.c:146 #2 vnc_server_info_get (vd=0x7f4b9e858000) at ui/vnc.c:223 #3 0x00007f4b9a29d318 in vnc_qmp_event (vs=0x7f4b9ef82000, vs=0x7f4b9ef82000, event=QAPI_EVENT_VNC_CONNECTED) at ui/vnc.c:279 #4 vnc_connect (vd=vd@entry=0x7f4b9e858000, sioc=sioc@entry=0x7f4b9e8b3a20, skipauth=skipauth@entry=true, websocket=websocket @entry=false) at ui/vnc.c:2994 #5 0x00007f4b9a29e8c8 in vnc_display_add_client (id=<optimized out>, csock=<optimized out>, skipauth=<optimized out>) at ui/v nc.c:3825 #6 0x00007f4b9a18d8a1 in qmp_marshal_add_client (args=<optimized out>, ret=<optimized out>, errp=0x7ffd5b8aa230) at qmp-marsh al.c:123 #7 0x00007f4b9a0b53f5 in handle_qmp_command (parser=<optimized out>, tokens=<optimized out>) at /usr/src/debug/qemu-2.6.0/mon itor.c:3922 #8 0x00007f4b9a348580 in json_message_process_token (lexer=0x7f4b9c78dfe8, input=0x7f4b9c7350e0, type=JSON_RCURLY, x=111, y=5 9) at qobject/json-streamer.c:94 #9 0x00007f4b9a35cfeb in json_lexer_feed_char (lexer=lexer@entry=0x7f4b9c78dfe8, ch=125 '}', flush=flush@entry=false) at qobj ect/json-lexer.c:310 #10 0x00007f4b9a35d0ae in json_lexer_feed (lexer=0x7f4b9c78dfe8, buffer=<optimized out>, size=<optimized out>) at qobject/json -lexer.c:360 #11 0x00007f4b9a348679 in json_message_parser_feed (parser=<optimized out>, buffer=<optimized out>, size=<optimized out>) at q object/json-streamer.c:114 #12 0x00007f4b9a0b3a1b in monitor_qmp_read (opaque=<optimized out>, buf=<optimized out>, size=<optimized out>) at /usr/src/deb ug/qemu-2.6.0/monitor.c:3938 #13 0x00007f4b9a186751 in tcp_chr_read (chan=<optimized out>, cond=<optimized out>, opaque=0x7f4b9c7add40) at qemu-char.c:2895 #14 0x00007f4b92b5c79a in g_main_context_dispatch () from /lib64/libglib-2.0.so.0 #15 0x00007f4b9a2bb0c0 in glib_pollfds_poll () at main-loop.c:213 #16 os_host_main_loop_wait (timeout=<optimized out>) at main-loop.c:258 #17 main_loop_wait (nonblocking=<optimized out>) at main-loop.c:506 #18 0x00007f4b9a0835cf in main_loop () at vl.c:1934 #19 main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4667 Do an upfront check for a NULL lsock and report an error to the caller, which matches behaviour from before commit 04d2529 Author: Daniel P. Berrange <berrange@redhat.com> Date: Fri Feb 27 16:20:57 2015 +0000 ui: convert VNC server to use QIOChannelSocket where getsockname() would be given a FD value -1 and thus report an error to the caller. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1470134726-15697-2-git-send-email-berrange@redhat.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

The vnc_server_info_get will allocate the VncServerInfo struct and then call vnc_init_basic_info_from_server_addr to populate the basic fields. If this returns an error though, the qapi_free_VncServerInfo call will then crash because the VncServerInfo struct instance was not properly NULL-initialized and thus contains random stack garbage. #0 0x00007f1987c8e6f5 in raise () at /lib64/libc.so.6 #1 0x00007f1987c902fa in abort () at /lib64/libc.so.6 #2 0x00007f1987ccf600 in __libc_message () at /lib64/libc.so.6 #3 0x00007f1987cd7d4a in _int_free () at /lib64/libc.so.6 #4 0x00007f1987cdb2ac in free () at /lib64/libc.so.6 #5 0x00007f198b654f6e in g_free () at /lib64/libglib-2.0.so.0 #6 0x0000559193cdcf54 in visit_type_str (v=v@entry= 0x5591972f14b0, name=name@entry=0x559193de1e29 "host", obj=obj@entry=0x5591961dbfa0, errp=errp@entry=0x7fffd7899d80) at qapi/qapi-visit-core.c:255 #7 0x0000559193cca8f3 in visit_type_VncBasicInfo_members (v=v@entry= 0x5591972f14b0, obj=obj@entry=0x5591961dbfa0, errp=errp@entry=0x7fffd7899dc0) at qapi-visit.c:12307 #8 0x0000559193ccb523 in visit_type_VncServerInfo_members (v=v@entry= 0x5591972f14b0, obj=0x5591961dbfa0, errp=errp@entry=0x7fffd7899e00) at qapi-visit.c:12632 #9 0x0000559193ccb60b in visit_type_VncServerInfo (v=v@entry= 0x5591972f14b0, name=name@entry=0x0, obj=obj@entry=0x7fffd7899e48, errp=errp@entry=0x0) at qapi-visit.c:12658 #10 0x0000559193cb53d8 in qapi_free_VncServerInfo (obj=<optimized out>) at qapi-types.c:3970 #11 0x0000559193c1e6ba in vnc_server_info_get (vd=0x7f1951498010) at ui/vnc.c:233 #12 0x0000559193c24275 in vnc_connect (vs=0x559197b2f200, vs=0x559197b2f200, event=QAPI_EVENT_VNC_CONNECTED) at ui/vnc.c:284 #13 0x0000559193c24275 in vnc_connect (vd=vd@entry=0x7f1951498010, sioc=sioc@entry=0x559196bf9c00, skipauth=skipauth@entry=tru e, websocket=websocket@entry=false) at ui/vnc.c:3039 #14 0x0000559193c25806 in vnc_display_add_client (id=<optimized out>, csock=<optimized out>, skipauth=<optimized out>) at ui/vnc.c:3877 #15 0x0000559193a90c28 in qmp_marshal_add_client (args=<optimized out>, ret=<optimized out>, errp=0x7fffd7899f90) at qmp-marshal.c:105 #16 0x000055919399c2b7 in handle_qmp_command (parser=<optimized out>, tokens=<optimized out>) at /home/berrange/src/virt/qemu/monitor.c:3971 #17 0x0000559193ce3307 in json_message_process_token (lexer=0x559194ab0838, input=0x559194a6d940, type=JSON_RCURLY, x=111, y=1 2) at qobject/json-streamer.c:105 #18 0x0000559193cfa90d in json_lexer_feed_char (lexer=lexer@entry=0x559194ab0838, ch=125 '}', flush=flush@entry=false) at qobject/json-lexer.c:319 #19 0x0000559193cfaa1e in json_lexer_feed (lexer=0x559194ab0838, buffer=<optimized out>, size=<optimized out>) at qobject/json-lexer.c:369 #20 0x0000559193ce33c9 in json_message_parser_feed (parser=<optimized out>, buffer=<optimized out>, size=<optimized out>) at qobject/json-streamer.c:124 #21 0x000055919399a85b in monitor_qmp_read (opaque=<optimized out>, buf=<optimized out>, size=<optimized out>) at /home/berrange/src/virt/qemu/monitor.c:3987 #22 0x0000559193a87d00 in tcp_chr_read (chan=<optimized out>, cond=<optimized out>, opaque=0x559194a7d900) at qemu-char.c:2895 #23 0x00007f198b64f703 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0 #24 0x0000559193c484b3 in main_loop_wait () at main-loop.c:213 #25 0x0000559193c484b3 in main_loop_wait (timeout=<optimized out>) at main-loop.c:258 #26 0x0000559193c484b3 in main_loop_wait (nonblocking=<optimized out>) at main-loop.c:506 #27 0x0000559193964c55 in main () at vl.c:1908 #28 0x0000559193964c55 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4603 This was introduced in commit 98481bf Author: Eric Blake <eblake@redhat.com> Date: Mon Oct 26 16:34:45 2015 -0600 vnc: Hoist allocation of VncBasicInfo to callers which added error reporting for vnc_init_basic_info_from_server_addr but didn't change the g_malloc calls to g_malloc0. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1470134726-15697-3-git-send-email-berrange@redhat.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

In the previous commit we fixed a crash when the guest read a register that pop from an empty FIFO. By auditing the repository, we found another similar use with an easy way to reproduce: $ qemu-system-aarch64 -M xlnx-zcu102 -monitor stdio -S QEMU 4.0.50 monitor - type 'help' for more information (qemu) xp/b 0xfd4a0134 Aborted (core dumped) (gdb) bt #0 0x00007f6936dea57f in raise () at /lib64/libc.so.6 #1 0x00007f6936dd4895 in abort () at /lib64/libc.so.6 #2 0x0000561ad32975ec in xlnx_dp_aux_pop_rx_fifo (s=0x7f692babee70) at hw/display/xlnx_dp.c:431 #3 0x0000561ad3297dc0 in xlnx_dp_read (opaque=0x7f692babee70, offset=77, size=4) at hw/display/xlnx_dp.c:667 #4 0x0000561ad321b896 in memory_region_read_accessor (mr=0x7f692babf620, addr=308, value=0x7ffe05c1db88, size=4, shift=0, mask=4294967295, attrs=...) at memory.c:439 #5 0x0000561ad321bd70 in access_with_adjusted_size (addr=308, value=0x7ffe05c1db88, size=1, access_size_min=4, access_size_max=4, access_fn=0x561ad321b858 <memory_region_read_accessor>, mr=0x7f692babf620, attrs=...) at memory.c:569 #6 0x0000561ad321e9d5 in memory_region_dispatch_read1 (mr=0x7f692babf620, addr=308, pval=0x7ffe05c1db88, size=1, attrs=...) at memory.c:1420 #7 0x0000561ad321ea9d in memory_region_dispatch_read (mr=0x7f692babf620, addr=308, pval=0x7ffe05c1db88, size=1, attrs=...) at memory.c:1447 #8 0x0000561ad31bd742 in flatview_read_continue (fv=0x561ad69c04f0, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1, addr1=308, l=1, mr=0x7f692babf620) at exec.c:3385 #9 0x0000561ad31bd895 in flatview_read (fv=0x561ad69c04f0, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1) at exec.c:3423 #10 0x0000561ad31bd90b in address_space_read_full (as=0x561ad5bb3020, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1) at exec.c:3436 #11 0x0000561ad33b1c42 in address_space_read (len=1, buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", attrs=..., addr=4249485620, as=0x561ad5bb3020) at include/exec/memory.h:2131 #12 0x0000561ad33b1c42 in memory_dump (mon=0x561ad59c4530, count=1, format=120, wsize=1, addr=4249485620, is_physical=1) at monitor/misc.c:723 #13 0x0000561ad33b1fc1 in hmp_physical_memory_dump (mon=0x561ad59c4530, qdict=0x561ad6c6fd00) at monitor/misc.c:795 #14 0x0000561ad37b4a9f in handle_hmp_command (mon=0x561ad59c4530, cmdline=0x561ad59d0f22 "/b 0x00000000fd4a0134") at monitor/hmp.c:1082 Fix by checking the FIFO is not empty before popping from it. The datasheet is not clear about the reset value of this register, we choose to return '0'. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-id: 20190709113715.7761-4-philmd@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org> (cherry picked from commit a09ef50) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

There's a race condition in which the tcp_chr_read() ioc handler can close a connection that is being written to from another thread. Running iotest 136 in a loop triggers this problem and crashes QEMU. (gdb) bt #0 0x00005558b842902d in object_get_class (obj=0x0) at qom/object.c:860 #1 0x00005558b84f92db in qio_channel_writev_full (ioc=0x0, iov=0x7ffc355decf0, niov=1, fds=0x0, nfds=0, errp=0x0) at io/channel.c:76 #2 0x00005558b84e0e9e in io_channel_send_full (ioc=0x0, buf=0x5558baf5beb0, len=138, fds=0x0, nfds=0) at chardev/char-io.c:123 #3 0x00005558b84e4a69 in tcp_chr_write (chr=0x5558ba460380, buf=0x5558baf5beb0 "...", len=138) at chardev/char-socket.c:135 #4 0x00005558b84dca55 in qemu_chr_write_buffer (s=0x5558ba460380, buf=0x5558baf5beb0 "...", len=138, offset=0x7ffc355dedd0, write_all=false) at chardev/char.c:112 #5 0x00005558b84dcbc2 in qemu_chr_write (s=0x5558ba460380, buf=0x5558baf5beb0 "...", len=138, write_all=false) at chardev/char.c:147 #6 0x00005558b84dfb26 in qemu_chr_fe_write (be=0x5558ba476610, buf=0x5558baf5beb0 "...", len=138) at chardev/char-fe.c:42 #7 0x00005558b8088c86 in monitor_flush_locked (mon=0x5558ba476610) at monitor.c:406 #8 0x00005558b8088e8c in monitor_puts (mon=0x5558ba476610, str=0x5558ba921e49 "") at monitor.c:449 #9 0x00005558b8089178 in qmp_send_response (mon=0x5558ba476610, rsp=0x5558bb161600) at monitor.c:498 #10 0x00005558b808920c in monitor_qapi_event_emit (event=QAPI_EVENT_SHUTDOWN, qdict=0x5558bb161600) at monitor.c:526 #11 0x00005558b8089307 in monitor_qapi_event_queue_no_reenter (event=QAPI_EVENT_SHUTDOWN, qdict=0x5558bb161600) at monitor.c:551 #12 0x00005558b80896c0 in qapi_event_emit (event=QAPI_EVENT_SHUTDOWN, qdict=0x5558bb161600) at monitor.c:626 #13 0x00005558b855f23b in qapi_event_send_shutdown (guest=false, reason=SHUTDOWN_CAUSE_HOST_QMP_QUIT) at qapi/qapi-events-run-state.c:43 #14 0x00005558b81911ef in qemu_system_shutdown (cause=SHUTDOWN_CAUSE_HOST_QMP_QUIT) at vl.c:1837 #15 0x00005558b8191308 in main_loop_should_exit () at vl.c:1885 #16 0x00005558b819140d in main_loop () at vl.c:1924 #17 0x00005558b8198c84 in main (argc=18, argv=0x7ffc355df3f8, envp=0x7ffc355df490) at vl.c:4665 This patch adds a lock to protect tcp_chr_disconnect() and socket_reconnect_timeout() Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Message-Id: <1565625509-404969-3-git-send-email-andrey.shinkevich@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Address Sanitizer shows memory leak in xhci_address_slot hw/usb/hcd-xhci.c:2156 and the stack is as bellow: Direct leak of 64 byte(s) in 4 object(s) allocated from: #0 0xffff91c6f5ab in realloc (/lib64/libasan.so.4+0xd35ab) qemu#1 0xffff91987243 in g_realloc (/lib64/libglib-2.0.so.0+0x57243) qemu#2 0xaaaab0b26a1f in qemu_iovec_add util/iov.c:296 qemu#3 0xaaaab07e5ce3 in xhci_address_slot hw/usb/hcd-xhci.c:2156 qemu#4 0xaaaab07e5ce3 in xhci_process_commands hw/usb/hcd-xhci.c:2493 qemu#5 0xaaaab00058d7 in memory_region_write_accessor qemu/memory.c:507 qemu#6 0xaaaab0000d87 in access_with_adjusted_size memory.c:573 qemu#7 0xaaaab000abcf in memory_region_dispatch_write memory.c:1516 qemu#8 0xaaaaaff59947 in flatview_write_continue exec.c:3367 qemu#9 0xaaaaaff59c33 in flatview_write exec.c:3406 qemu#10 0xaaaaaff63b3b in address_space_write exec.c:3496 qemu#11 0xaaaab002f263 in kvm_cpu_exec accel/kvm/kvm-all.c:2288 qemu#12 0xaaaaaffee427 in qemu_kvm_cpu_thread_fn cpus.c:1290 qemu#13 0xaaaab0b1a943 in qemu_thread_start util/qemu-thread-posix.c:502 qemu#14 0xffff908ce8bb in start_thread (/lib64/libpthread.so.0+0x78bb) qemu#15 0xffff908165cb in thread_start (/lib64/libc.so.6+0xd55cb) Cc: zhanghailiang <zhang.zhanghailiang@huawei.com> Signed-off-by: Ying Fang <fangying1@huawei.com> Reviewed-by: Li Qiang <liq3ea@gmail.com> Message-id: 20190827080209.2365-1-fangying1@huawei.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

When 'system_reset' is called, the main loop clear the memory region cache before the BH has a chance to execute. Later when the deferred function is called, some assumptions that were made when scheduling them are no longer true when they actually execute. This is what happens using a virtio-blk device (fresh RHEL7.8 install): $ (sleep 12.3; echo system_reset; sleep 12.3; echo system_reset; sleep 1; echo q) \ | qemu-system-x86_64 -m 4G -smp 8 -boot menu=on \ -device virtio-blk-pci,id=image1,drive=drive_image1 \ -drive file=/var/lib/libvirt/images/rhel78.qcow2,if=none,id=drive_image1,format=qcow2,cache=none \ -device virtio-net-pci,netdev=net0,id=nic0,mac=52:54:00:c4:e7:84 \ -netdev tap,id=net0,script=/bin/true,downscript=/bin/true,vhost=on \ -monitor stdio -serial null -nographic (qemu) system_reset (qemu) system_reset (qemu) qemu-system-x86_64: hw/virtio/virtio.c:225: vring_get_region_caches: Assertion `caches != NULL' failed. Aborted (gdb) bt Thread 1 (Thread 0x7f109c17b680 (LWP 10939)): #0 0x00005604083296d1 in vring_get_region_caches (vq=0x56040a24bdd0) at hw/virtio/virtio.c:227 #1 0x000056040832972b in vring_avail_flags (vq=0x56040a24bdd0) at hw/virtio/virtio.c:235 #2 0x000056040832d13d in virtio_should_notify (vdev=0x56040a240630, vq=0x56040a24bdd0) at hw/virtio/virtio.c:1648 #3 0x000056040832d1f8 in virtio_notify_irqfd (vdev=0x56040a240630, vq=0x56040a24bdd0) at hw/virtio/virtio.c:1662 #4 0x00005604082d213d in notify_guest_bh (opaque=0x56040a243ec0) at hw/block/dataplane/virtio-blk.c:75 #5 0x000056040883dc35 in aio_bh_call (bh=0x56040a243f10) at util/async.c:90 #6 0x000056040883dccd in aio_bh_poll (ctx=0x560409161980) at util/async.c:118 #7 0x0000560408842af7 in aio_dispatch (ctx=0x560409161980) at util/aio-posix.c:460 #8 0x000056040883e068 in aio_ctx_dispatch (source=0x560409161980, callback=0x0, user_data=0x0) at util/async.c:261 #9 0x00007f10a8fca06d in g_main_context_dispatch () at /lib64/libglib-2.0.so.0 #10 0x0000560408841445 in glib_pollfds_poll () at util/main-loop.c:215 #11 0x00005604088414bf in os_host_main_loop_wait (timeout=0) at util/main-loop.c:238 #12 0x00005604088415c4 in main_loop_wait (nonblocking=0) at util/main-loop.c:514 #13 0x0000560408416b1e in main_loop () at vl.c:1923 #14 0x000056040841e0e8 in main (argc=20, argv=0x7ffc2c3f9c58, envp=0x7ffc2c3f9d00) at vl.c:4578 Fix this by cancelling the BH when the virtio dataplane is stopped. [This is version of the patch was modified as discussed with Philippe on the mailing list thread. --Stefan] Reported-by: Yihuang Yu <yihyu@redhat.com> Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Fixes: https://bugs.launchpad.net/qemu/+bug/1839428 Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20190816171503.24761-1-philmd@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Even for block nodes with bs->drv == NULL, we can't just ignore a bdrv_set_aio_context() call. Leaving the node in its old context can mean that it's still in an iothread context in bdrv_close_all() during shutdown, resulting in an attempted unlock of the AioContext lock which we don't hold. This is an example stack trace of a related crash: #0 0x00007ffff59da57f in raise () at /lib64/libc.so.6 #1 0x00007ffff59c4895 in abort () at /lib64/libc.so.6 #2 0x0000555555b97b1e in error_exit (err=<optimized out>, msg=msg@entry=0x555555d386d0 <__func__.19059> "qemu_mutex_unlock_impl") at util/qemu-thread-posix.c:36 #3 0x0000555555b97f7f in qemu_mutex_unlock_impl (mutex=mutex@entry=0x5555568002f0, file=file@entry=0x555555d378df "util/async.c", line=line@entry=507) at util/qemu-thread-posix.c:97 #4 0x0000555555b92f55 in aio_context_release (ctx=ctx@entry=0x555556800290) at util/async.c:507 #5 0x0000555555b05cf8 in bdrv_prwv_co (child=child@entry=0x7fffc80012f0, offset=offset@entry=131072, qiov=qiov@entry=0x7fffffffd4f0, is_write=is_write@entry=true, flags=flags@entry=0) at block/io.c:833 #6 0x0000555555b060a9 in bdrv_pwritev (qiov=0x7fffffffd4f0, offset=131072, child=0x7fffc80012f0) at block/io.c:990 #7 0x0000555555b060a9 in bdrv_pwrite (child=0x7fffc80012f0, offset=131072, buf=<optimized out>, bytes=<optimized out>) at block/io.c:990 #8 0x0000555555ae172b in qcow2_cache_entry_flush (bs=bs@entry=0x555556810680, c=c@entry=0x5555568cc740, i=i@entry=0) at block/qcow2-cache.c:51 #9 0x0000555555ae18dd in qcow2_cache_write (bs=bs@entry=0x555556810680, c=0x5555568cc740) at block/qcow2-cache.c:248 #10 0x0000555555ae15de in qcow2_cache_flush (bs=0x555556810680, c=<optimized out>) at block/qcow2-cache.c:259 #11 0x0000555555ae16b1 in qcow2_cache_flush_dependency (c=0x5555568a1700, c=0x5555568a1700, bs=0x555556810680) at block/qcow2-cache.c:194 #12 0x0000555555ae16b1 in qcow2_cache_entry_flush (bs=bs@entry=0x555556810680, c=c@entry=0x5555568a1700, i=i@entry=0) at block/qcow2-cache.c:194 #13 0x0000555555ae18dd in qcow2_cache_write (bs=bs@entry=0x555556810680, c=0x5555568a1700) at block/qcow2-cache.c:248 #14 0x0000555555ae15de in qcow2_cache_flush (bs=bs@entry=0x555556810680, c=<optimized out>) at block/qcow2-cache.c:259 #15 0x0000555555ad242c in qcow2_inactivate (bs=bs@entry=0x555556810680) at block/qcow2.c:2124 #16 0x0000555555ad2590 in qcow2_close (bs=0x555556810680) at block/qcow2.c:2153 #17 0x0000555555ab0c62 in bdrv_close (bs=0x555556810680) at block.c:3358 #18 0x0000555555ab0c62 in bdrv_delete (bs=0x555556810680) at block.c:3542 #19 0x0000555555ab0c62 in bdrv_unref (bs=0x555556810680) at block.c:4598 #20 0x0000555555af4d72 in blk_remove_bs (blk=blk@entry=0x5555568103d0) at block/block-backend.c:785 #21 0x0000555555af4dbb in blk_remove_all_bs () at block/block-backend.c:483 #22 0x0000555555aae02f in bdrv_close_all () at block.c:3412 #23 0x00005555557f9796 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4776 The reproducer I used is a qcow2 image on gluster volume, where the virtual disk size (4 GB) is larger than the gluster volume size (64M), so we can easily trigger an ENOSPC. This backend is assigned to a virtio-blk device using an iothread, and then from the guest a 'dd if=/dev/zero of=/dev/vda bs=1G count=1' causes the VM to stop because of an I/O error. qemu_gluster_co_flush_to_disk() sets bs->drv = NULL on error, so when virtio-blk stops the dataplane, the block nodes stay in the iothread AioContext. A 'quit' monitor command issued from this paused state crashes the process. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1631227 Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> (cherry picked from commit 1bffe1a) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

Reading the RX_DATA register when the RX_FIFO is empty triggers an abort. This can be easily reproduced: $ qemu-system-arm -M emcraft-sf2 -monitor stdio -S QEMU 4.0.50 monitor - type 'help' for more information (qemu) x 0x40001010 Aborted (core dumped) (gdb) bt #1 0x00007f035874f895 in abort () at /lib64/libc.so.6 #2 0x00005628686591ff in fifo8_pop (fifo=0x56286a9a4c68) at util/fifo8.c:66 #3 0x00005628683e0b8e in fifo32_pop (fifo=0x56286a9a4c68) at include/qemu/fifo32.h:137 #4 0x00005628683e0efb in spi_read (opaque=0x56286a9a4850, addr=4, size=4) at hw/ssi/mss-spi.c:168 #5 0x0000562867f96801 in memory_region_read_accessor (mr=0x56286a9a4b60, addr=16, value=0x7ffeecb0c5c8, size=4, shift=0, mask=4294967295, attrs=...) at memory.c:439 #6 0x0000562867f96cdb in access_with_adjusted_size (addr=16, value=0x7ffeecb0c5c8, size=4, access_size_min=1, access_size_max=4, access_fn=0x562867f967c3 <memory_region_read_accessor>, mr=0x56286a9a4b60, attrs=...) at memory.c:569 #7 0x0000562867f99940 in memory_region_dispatch_read1 (mr=0x56286a9a4b60, addr=16, pval=0x7ffeecb0c5c8, size=4, attrs=...) at memory.c:1420 #8 0x0000562867f99a08 in memory_region_dispatch_read (mr=0x56286a9a4b60, addr=16, pval=0x7ffeecb0c5c8, size=4, attrs=...) at memory.c:1447 #9 0x0000562867f38721 in flatview_read_continue (fv=0x56286aec6360, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, addr1=16, l=4, mr=0x56286a9a4b60) at exec.c:3385 #10 0x0000562867f38874 in flatview_read (fv=0x56286aec6360, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4) at exec.c:3423 #11 0x0000562867f388ea in address_space_read_full (as=0x56286aa3e890, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4) at exec.c:3436 #12 0x0000562867f389c5 in address_space_rw (as=0x56286aa3e890, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, is_write=false) at exec.c:3466 #13 0x0000562867f3bdd7 in cpu_memory_rw_debug (cpu=0x56286aa19d00, addr=1073745936, buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, is_write=0) at exec.c:3976 #14 0x000056286811ed51 in memory_dump (mon=0x56286a8c32d0, count=1, format=120, wsize=4, addr=1073745936, is_physical=0) at monitor/misc.c:730 #15 0x000056286811eff1 in hmp_memory_dump (mon=0x56286a8c32d0, qdict=0x56286b15c400) at monitor/misc.c:785 #16 0x00005628684740ee in handle_hmp_command (mon=0x56286a8c32d0, cmdline=0x56286a8caeb2 "0x40001010") at monitor/hmp.c:1082 From the datasheet "Actel SmartFusion Microcontroller Subsystem User's Guide" Rev.1, Table 13-3 "SPI Register Summary", this register has a reset value of 0. Check the FIFO is not empty before accessing it, else log an error message. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-id: 20190709113715.7761-3-philmd@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org> (cherry picked from commit c0bccee) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

In the previous commit we fixed a crash when the guest read a register that pop from an empty FIFO. By auditing the repository, we found another similar use with an easy way to reproduce: $ qemu-system-aarch64 -M xlnx-zcu102 -monitor stdio -S QEMU 4.0.50 monitor - type 'help' for more information (qemu) xp/b 0xfd4a0134 Aborted (core dumped) (gdb) bt #0 0x00007f6936dea57f in raise () at /lib64/libc.so.6 #1 0x00007f6936dd4895 in abort () at /lib64/libc.so.6 #2 0x0000561ad32975ec in xlnx_dp_aux_pop_rx_fifo (s=0x7f692babee70) at hw/display/xlnx_dp.c:431 #3 0x0000561ad3297dc0 in xlnx_dp_read (opaque=0x7f692babee70, offset=77, size=4) at hw/display/xlnx_dp.c:667 #4 0x0000561ad321b896 in memory_region_read_accessor (mr=0x7f692babf620, addr=308, value=0x7ffe05c1db88, size=4, shift=0, mask=4294967295, attrs=...) at memory.c:439 #5 0x0000561ad321bd70 in access_with_adjusted_size (addr=308, value=0x7ffe05c1db88, size=1, access_size_min=4, access_size_max=4, access_fn=0x561ad321b858 <memory_region_read_accessor>, mr=0x7f692babf620, attrs=...) at memory.c:569 #6 0x0000561ad321e9d5 in memory_region_dispatch_read1 (mr=0x7f692babf620, addr=308, pval=0x7ffe05c1db88, size=1, attrs=...) at memory.c:1420 #7 0x0000561ad321ea9d in memory_region_dispatch_read (mr=0x7f692babf620, addr=308, pval=0x7ffe05c1db88, size=1, attrs=...) at memory.c:1447 #8 0x0000561ad31bd742 in flatview_read_continue (fv=0x561ad69c04f0, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1, addr1=308, l=1, mr=0x7f692babf620) at exec.c:3385 #9 0x0000561ad31bd895 in flatview_read (fv=0x561ad69c04f0, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1) at exec.c:3423 #10 0x0000561ad31bd90b in address_space_read_full (as=0x561ad5bb3020, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1) at exec.c:3436 #11 0x0000561ad33b1c42 in address_space_read (len=1, buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", attrs=..., addr=4249485620, as=0x561ad5bb3020) at include/exec/memory.h:2131 #12 0x0000561ad33b1c42 in memory_dump (mon=0x561ad59c4530, count=1, format=120, wsize=1, addr=4249485620, is_physical=1) at monitor/misc.c:723 #13 0x0000561ad33b1fc1 in hmp_physical_memory_dump (mon=0x561ad59c4530, qdict=0x561ad6c6fd00) at monitor/misc.c:795 #14 0x0000561ad37b4a9f in handle_hmp_command (mon=0x561ad59c4530, cmdline=0x561ad59d0f22 "/b 0x00000000fd4a0134") at monitor/hmp.c:1082 Fix by checking the FIFO is not empty before popping from it. The datasheet is not clear about the reset value of this register, we choose to return '0'. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-id: 20190709113715.7761-4-philmd@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org> (cherry picked from commit a09ef50) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

It fixes heap-use-after-free which was found by clang's ASAN. Control flow of this use-after-free: main_thread: * Got SIGTERM and completes main loop * Calls migration_shutdown - migrate_fd_cancel (so, migration_thread begins to complete) - object_unref(OBJECT(current_migration)); migration_thread: * migration_iteration_finish -> schedule cleanup bh * object_unref(OBJECT(s)); (Now, current_migration is freed) * exits main_thread: * Calls vm_shutdown -> drain bdrvs -> main loop -> cleanup_bh -> use after free If you want to reproduce, these couple of sleeps will help: vl.c:4613: migration_shutdown(); + sleep(2); migration.c:3269: + sleep(1); trace_migration_thread_after_loop(); migration_iteration_finish(s); Original output: qemu-system-x86_64: terminating on signal 15 from pid 31980 (<unknown process>) ================================================================= ==31958==ERROR: AddressSanitizer: heap-use-after-free on address 0x61900001d210 at pc 0x555558a535ca bp 0x7fffffffb190 sp 0x7fffffffb188 READ of size 8 at 0x61900001d210 thread T0 (qemu-vm-0) #0 0x555558a535c9 in migrate_fd_cleanup migration/migration.c:1502:23 #1 0x5555594fde0a in aio_bh_call util/async.c:90:5 #2 0x5555594fe522 in aio_bh_poll util/async.c:118:13 #3 0x555559524783 in aio_poll util/aio-posix.c:725:17 #4 0x555559504fb3 in aio_wait_bh_oneshot util/aio-wait.c:71:5 #5 0x5555573bddf6 in virtio_blk_data_plane_stop hw/block/dataplane/virtio-blk.c:282:5 #6 0x5555589d5c09 in virtio_bus_stop_ioeventfd hw/virtio/virtio-bus.c:246:9 #7 0x5555589e9917 in virtio_pci_stop_ioeventfd hw/virtio/virtio-pci.c:287:5 #8 0x5555589e22bf in virtio_pci_vmstate_change hw/virtio/virtio-pci.c:1072:9 #9 0x555557628931 in virtio_vmstate_change hw/virtio/virtio.c:2257:9 #10 0x555557c36713 in vm_state_notify vl.c:1605:9 #11 0x55555716ef53 in do_vm_stop cpus.c:1074:9 #12 0x55555716eeff in vm_shutdown cpus.c:1092:12 #13 0x555557c4283e in main vl.c:4617:5 #14 0x7fffdfdb482f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f) #15 0x555556ecb118 in _start (x86_64-softmmu/qemu-system-x86_64+0x1977118) 0x61900001d210 is located 144 bytes inside of 952-byte region [0x61900001d180,0x61900001d538) freed by thread T6 (live_migration) here: #0 0x555556f76782 in __interceptor_free /tmp/final/llvm.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:124:3 #1 0x555558d5fa94 in object_finalize qom/object.c:618:9 #2 0x555558d57651 in object_unref qom/object.c:1068:9 #3 0x555558a55588 in migration_thread migration/migration.c:3272:5 #4 0x5555595393f2 in qemu_thread_start util/qemu-thread-posix.c:502:9 #5 0x7fffe057f6b9 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76b9) previously allocated by thread T0 (qemu-vm-0) here: #0 0x555556f76b03 in __interceptor_malloc /tmp/final/llvm.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:146:3 #1 0x7ffff6ee37b8 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x4f7b8) #2 0x555558d58031 in object_new qom/object.c:640:12 #3 0x555558a31f21 in migration_object_init migration/migration.c:139:25 #4 0x555557c41398 in main vl.c:4320:5 #5 0x7fffdfdb482f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f) Thread T6 (live_migration) created by T0 (qemu-vm-0) here: #0 0x555556f5f0dd in pthread_create /tmp/final/llvm.src/projects/compiler-rt/lib/asan/asan_interceptors.cc:210:3 #1 0x555559538cf9 in qemu_thread_create util/qemu-thread-posix.c:539:11 #2 0x555558a53304 in migrate_fd_connect migration/migration.c:3332:5 #3 0x555558a72bd8 in migration_channel_connect migration/channel.c:92:5 #4 0x555558a6ef87 in exec_start_outgoing_migration migration/exec.c:42:5 #5 0x555558a4f3c2 in qmp_migrate migration/migration.c:1922:9 #6 0x555558bb4f6a in qmp_marshal_migrate qapi/qapi-commands-migration.c:607:5 #7 0x555559363738 in do_qmp_dispatch qapi/qmp-dispatch.c:131:5 #8 0x555559362a15 in qmp_dispatch qapi/qmp-dispatch.c:174:11 #9 0x5555571bac15 in monitor_qmp_dispatch monitor.c:4124:11 #10 0x55555719a22d in monitor_qmp_bh_dispatcher monitor.c:4207:9 #11 0x5555594fde0a in aio_bh_call util/async.c:90:5 #12 0x5555594fe522 in aio_bh_poll util/async.c:118:13 #13 0x5555595201e0 in aio_dispatch util/aio-posix.c:460:5 #14 0x555559503553 in aio_ctx_dispatch util/async.c:261:5 #15 0x7ffff6ede196 in g_main_context_dispatch (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x4a196) SUMMARY: AddressSanitizer: heap-use-after-free migration/migration.c:1502:23 in migrate_fd_cleanup Shadow bytes around the buggy address: 0x0c327fffb9f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c327fffba00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c327fffba10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c327fffba20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c327fffba30: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd =>0x0c327fffba40: fd fd[fd]fd fd fd fd fd fd fd fd fd fd fd fd fd 0x0c327fffba50: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x0c327fffba60: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x0c327fffba70: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x0c327fffba80: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x0c327fffba90: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 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 ==31958==ABORTING Signed-off-by: Yury Kotov <yury-kotov@yandex-team.ru> Message-Id: <20190408113343.2370-1-yury-kotov@yandex-team.ru> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Fixed up comment formatting (cherry picked from commit fd392cf) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

When 'system_reset' is called, the main loop clear the memory region cache before the BH has a chance to execute. Later when the deferred function is called, some assumptions that were made when scheduling them are no longer true when they actually execute. This is what happens using a virtio-blk device (fresh RHEL7.8 install): $ (sleep 12.3; echo system_reset; sleep 12.3; echo system_reset; sleep 1; echo q) \ | qemu-system-x86_64 -m 4G -smp 8 -boot menu=on \ -device virtio-blk-pci,id=image1,drive=drive_image1 \ -drive file=/var/lib/libvirt/images/rhel78.qcow2,if=none,id=drive_image1,format=qcow2,cache=none \ -device virtio-net-pci,netdev=net0,id=nic0,mac=52:54:00:c4:e7:84 \ -netdev tap,id=net0,script=/bin/true,downscript=/bin/true,vhost=on \ -monitor stdio -serial null -nographic (qemu) system_reset (qemu) system_reset (qemu) qemu-system-x86_64: hw/virtio/virtio.c:225: vring_get_region_caches: Assertion `caches != NULL' failed. Aborted (gdb) bt Thread 1 (Thread 0x7f109c17b680 (LWP 10939)): #0 0x00005604083296d1 in vring_get_region_caches (vq=0x56040a24bdd0) at hw/virtio/virtio.c:227 #1 0x000056040832972b in vring_avail_flags (vq=0x56040a24bdd0) at hw/virtio/virtio.c:235 #2 0x000056040832d13d in virtio_should_notify (vdev=0x56040a240630, vq=0x56040a24bdd0) at hw/virtio/virtio.c:1648 #3 0x000056040832d1f8 in virtio_notify_irqfd (vdev=0x56040a240630, vq=0x56040a24bdd0) at hw/virtio/virtio.c:1662 #4 0x00005604082d213d in notify_guest_bh (opaque=0x56040a243ec0) at hw/block/dataplane/virtio-blk.c:75 #5 0x000056040883dc35 in aio_bh_call (bh=0x56040a243f10) at util/async.c:90 #6 0x000056040883dccd in aio_bh_poll (ctx=0x560409161980) at util/async.c:118 #7 0x0000560408842af7 in aio_dispatch (ctx=0x560409161980) at util/aio-posix.c:460 #8 0x000056040883e068 in aio_ctx_dispatch (source=0x560409161980, callback=0x0, user_data=0x0) at util/async.c:261 #9 0x00007f10a8fca06d in g_main_context_dispatch () at /lib64/libglib-2.0.so.0 #10 0x0000560408841445 in glib_pollfds_poll () at util/main-loop.c:215 #11 0x00005604088414bf in os_host_main_loop_wait (timeout=0) at util/main-loop.c:238 #12 0x00005604088415c4 in main_loop_wait (nonblocking=0) at util/main-loop.c:514 #13 0x0000560408416b1e in main_loop () at vl.c:1923 #14 0x000056040841e0e8 in main (argc=20, argv=0x7ffc2c3f9c58, envp=0x7ffc2c3f9d00) at vl.c:4578 Fix this by cancelling the BH when the virtio dataplane is stopped. [This is version of the patch was modified as discussed with Philippe on the mailing list thread. --Stefan] Reported-by: Yihuang Yu <yihyu@redhat.com> Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Fixes: https://bugs.launchpad.net/qemu/+bug/1839428 Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20190816171503.24761-1-philmd@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> (cherry picked from commit ebb6ff2) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

Currently the SLOF firmware for pseries guests will disable/re-enable a PCI device multiple times via IO/MEM/MASTER bits of PCI_COMMAND register after the initial probe/feature negotiation, as it tends to work with a single device at a time at various stages like probing and running block/network bootloaders without doing a full reset in-between. In QEMU, when PCI_COMMAND_MASTER is disabled we disable the corresponding IOMMU memory region, so DMA accesses (including to vring fields like idx/flags) will no longer undergo the necessary translation. Normally we wouldn't expect this to happen since it would be misbehavior on the driver side to continue driving DMA requests. However, in the case of pseries, with iommu_platform=on, we trigger the following sequence when tearing down the virtio-blk dataplane ioeventfd in response to the guest unsetting PCI_COMMAND_MASTER: #2 0x0000555555922651 in virtqueue_map_desc (vdev=vdev@entry=0x555556dbcfb0, p_num_sg=p_num_sg@entry=0x7fffe657e1a8, addr=addr@entry=0x7fffe657e240, iov=iov@entry=0x7fffe6580240, max_num_sg=max_num_sg@entry=1024, is_write=is_write@entry=false, pa=0, sz=0) at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:757 #3 0x0000555555922a89 in virtqueue_pop (vq=vq@entry=0x555556dc8660, sz=sz@entry=184) at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:950 #4 0x00005555558d3eca in virtio_blk_get_request (vq=0x555556dc8660, s=0x555556dbcfb0) at /home/mdroth/w/qemu.git/hw/block/virtio-blk.c:255 #5 0x00005555558d3eca in virtio_blk_handle_vq (s=0x555556dbcfb0, vq=0x555556dc8660) at /home/mdroth/w/qemu.git/hw/block/virtio-blk.c:776 #6 0x000055555591dd66 in virtio_queue_notify_aio_vq (vq=vq@entry=0x555556dc8660) at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:1550 #7 0x000055555591ecef in virtio_queue_notify_aio_vq (vq=0x555556dc8660) at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:1546 #8 0x000055555591ecef in virtio_queue_host_notifier_aio_poll (opaque=0x555556dc86c8) at /home/mdroth/w/qemu.git/hw/virtio/virtio.c:2527 #9 0x0000555555d02164 in run_poll_handlers_once (ctx=ctx@entry=0x55555688bfc0, timeout=timeout@entry=0x7fffe65844a8) at /home/mdroth/w/qemu.git/util/aio-posix.c:520 #10 0x0000555555d02d1b in try_poll_mode (timeout=0x7fffe65844a8, ctx=0x55555688bfc0) at /home/mdroth/w/qemu.git/util/aio-posix.c:607 #11 0x0000555555d02d1b in aio_poll (ctx=ctx@entry=0x55555688bfc0, blocking=blocking@entry=true) at /home/mdroth/w/qemu.git/util/aio-posix.c:639 #12 0x0000555555d0004d in aio_wait_bh_oneshot (ctx=0x55555688bfc0, cb=cb@entry=0x5555558d5130 <virtio_blk_data_plane_stop_bh>, opaque=opaque@entry=0x555556de86f0) at /home/mdroth/w/qemu.git/util/aio-wait.c:71 #13 0x00005555558d59bf in virtio_blk_data_plane_stop (vdev=<optimized out>) at /home/mdroth/w/qemu.git/hw/block/dataplane/virtio-blk.c:288 #14 0x0000555555b906a1 in virtio_bus_stop_ioeventfd (bus=bus@entry=0x555556dbcf38) at /home/mdroth/w/qemu.git/hw/virtio/virtio-bus.c:245 #15 0x0000555555b90dbb in virtio_bus_stop_ioeventfd (bus=bus@entry=0x555556dbcf38) at /home/mdroth/w/qemu.git/hw/virtio/virtio-bus.c:237 #16 0x0000555555b92a8e in virtio_pci_stop_ioeventfd (proxy=0x555556db4e40) at /home/mdroth/w/qemu.git/hw/virtio/virtio-pci.c:292 #17 0x0000555555b92a8e in virtio_write_config (pci_dev=0x555556db4e40, address=<optimized out>, val=1048832, len=<optimized out>) at /home/mdroth/w/qemu.git/hw/virtio/virtio-pci.c:613 I.e. the calling code is only scheduling a one-shot BH for virtio_blk_data_plane_stop_bh, but somehow we end up trying to process an additional virtqueue entry before we get there. This is likely due to the following check in virtio_queue_host_notifier_aio_poll: static bool virtio_queue_host_notifier_aio_poll(void *opaque) { EventNotifier *n = opaque; VirtQueue *vq = container_of(n, VirtQueue, host_notifier); bool progress; if (!vq->vring.desc || virtio_queue_empty(vq)) { return false; } progress = virtio_queue_notify_aio_vq(vq); namely the call to virtio_queue_empty(). In this case, since no new requests have actually been issued, shadow_avail_idx == last_avail_idx, so we actually try to access the vring via vring_avail_idx() to get the latest non-shadowed idx: int virtio_queue_empty(VirtQueue *vq) { bool empty; ... if (vq->shadow_avail_idx != vq->last_avail_idx) { return 0; } rcu_read_lock(); empty = vring_avail_idx(vq) == vq->last_avail_idx; rcu_read_unlock(); return empty; but since the IOMMU region has been disabled we get a bogus value (0 usually), which causes virtio_queue_empty() to falsely report that there are entries to be processed, which causes errors such as: "virtio: zero sized buffers are not allowed" or "virtio-blk missing headers" and puts the device in an error state. This patch works around the issue by introducing virtio_set_disabled(), which sets a 'disabled' flag to bypass checks like virtio_queue_empty() when bus-mastering is disabled. Since we'd check this flag at all the same sites as vdev->broken, we replace those checks with an inline function which checks for either vdev->broken or vdev->disabled. The 'disabled' flag is only migrated when set, which should be fairly rare, but to maintain migration compatibility we disable it's use for older machine types. Users requiring the use of the flag in conjunction with older machine types can set it explicitly as a virtio-device option. NOTES: - This leaves some other oddities in play, like the fact that DRIVER_OK also gets unset in response to bus-mastering being disabled, but not restored (however the device seems to continue working) - Similarly, we disable the host notifier via virtio_bus_stop_ioeventfd(), which seems to move the handling out of virtio-blk dataplane and back into the main IO thread, and it ends up staying there till a reset (but otherwise continues working normally) Cc: David Gibson <david@gibson.dropbear.id.au>, Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Message-Id: <20191120005003.27035-1-mdroth@linux.vnet.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

All paths that lead to bdrv_backup_top_drop(), except for the call from backup_clean(), imply that the BDS AioContext has already been acquired, so doing it there too can potentially lead to QEMU hanging on AIO_WAIT_WHILE(). An easy way to trigger this situation is by issuing a two actions transaction, with a proper and a bogus blockdev-backup, so the second one will trigger a rollback. This will trigger a hang with an stack trace like this one: #0 0x00007fb680c75016 in __GI_ppoll (fds=0x55e74580f7c0, nfds=1, timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39 qemu#1 0x000055e743386e09 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77 qemu#2 0x000055e743386e09 in qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at util/qemu-timer.c:336 qemu#3 0x000055e743388dc4 in aio_poll (ctx=0x55e7458925d0, blocking=blocking@entry=true) at util/aio-posix.c:669 qemu#4 0x000055e743305dea in bdrv_flush (bs=bs@entry=0x55e74593c0d0) at block/io.c:2878 qemu#5 0x000055e7432be58e in bdrv_close (bs=0x55e74593c0d0) at block.c:4017 qemu#6 0x000055e7432be58e in bdrv_delete (bs=<optimized out>) at block.c:4262 qemu#7 0x000055e7432be58e in bdrv_unref (bs=bs@entry=0x55e74593c0d0) at block.c:5644 qemu#8 0x000055e743316b9b in bdrv_backup_top_drop (bs=bs@entry=0x55e74593c0d0) at block/backup-top.c:273 qemu#9 0x000055e74331461f in backup_job_create (job_id=0x0, bs=bs@entry=0x55e7458d5820, target=target@entry=0x55e74589f640, speed=0, sync_mode=MIRROR_SYNC_MODE_FULL, sync_bitmap=sync_bitmap@entry=0x0, bitmap_mode=BITMAP_SYNC_MODE_ON_SUCCESS, compress=false, filter_node_name=0x0, on_source_error=BLOCKDEV_ON_ERROR_REPORT, on_target_error=BLOCKDEV_ON_ERROR_REPORT, creation_flags=0, cb=0x0, opaque=0x0, txn=0x0, errp=0x7ffddfd1efb0) at block/backup.c:478 qemu#10 0x000055e74315bc52 in do_backup_common (backup=backup@entry=0x55e746c066d0, bs=bs@entry=0x55e7458d5820, target_bs=target_bs@entry=0x55e74589f640, aio_context=aio_context@entry=0x55e7458a91e0, txn=txn@entry=0x0, errp=errp@entry=0x7ffddfd1efb0) at blockdev.c:3580 qemu#11 0x000055e74315c37c in do_blockdev_backup (backup=backup@entry=0x55e746c066d0, txn=0x0, errp=errp@entry=0x7ffddfd1efb0) at /usr/src/debug/qemu-kvm-4.2.0-2.module+el8.2.0+5135+ed3b2489.x86_64/./qapi/qapi-types-block-core.h:1492 qemu#12 0x000055e74315c449 in blockdev_backup_prepare (common=0x55e746a8de90, errp=0x7ffddfd1f018) at blockdev.c:1885 qemu#13 0x000055e743160152 in qmp_transaction (dev_list=<optimized out>, has_props=<optimized out>, props=0x55e7467fe2c0, errp=errp@entry=0x7ffddfd1f088) at blockdev.c:2340 qemu#14 0x000055e743287ff5 in qmp_marshal_transaction (args=<optimized out>, ret=<optimized out>, errp=0x7ffddfd1f0f8) at qapi/qapi-commands-transaction.c:44 qemu#15 0x000055e74333de6c in do_qmp_dispatch (errp=0x7ffddfd1f0f0, allow_oob=<optimized out>, request=<optimized out>, cmds=0x55e743c28d60 <qmp_commands>) at qapi/qmp-dispatch.c:132 qemu#16 0x000055e74333de6c in qmp_dispatch (cmds=0x55e743c28d60 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175 qemu#17 0x000055e74325c061 in monitor_qmp_dispatch (mon=0x55e745908030, req=<optimized out>) at monitor/qmp.c:145 qemu#18 0x000055e74325c6fa in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:234 qemu#19 0x000055e743385866 in aio_bh_call (bh=0x55e745807ae0) at util/async.c:117 qemu#20 0x000055e743385866 in aio_bh_poll (ctx=ctx@entry=0x55e7458067a0) at util/async.c:117 qemu#21 0x000055e743388c54 in aio_dispatch (ctx=0x55e7458067a0) at util/aio-posix.c:459 qemu#22 0x000055e743385742 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260 qemu#23 0x00007fb68543e67d in g_main_dispatch (context=0x55e745893a40) at gmain.c:3176 qemu#24 0x00007fb68543e67d in g_main_context_dispatch (context=context@entry=0x55e745893a40) at gmain.c:3829 qemu#25 0x000055e743387d08 in glib_pollfds_poll () at util/main-loop.c:219 qemu#26 0x000055e743387d08 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242 qemu#27 0x000055e743387d08 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518 qemu#28 0x000055e74316a3c1 in main_loop () at vl.c:1828 qemu#29 0x000055e743016a72 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504 Fix this by not acquiring the AioContext there, and ensuring all paths leading to it have it already acquired (backup_clean()). RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1782111 Signed-off-by: Sergio Lopez <slp@redhat.com>

Dirty map addition and removal functions are not acquiring to BDS AioContext, while they may call to code that expects it to be acquired. This may trigger a crash with a stack trace like this one: #0 0x00007f0ef146370f in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 qemu#1 0x00007f0ef144db25 in __GI_abort () at abort.c:79 qemu#2 0x0000565022294dce in error_exit (err=<optimized out>, msg=msg@entry=0x56502243a730 <__func__.16350> "qemu_mutex_unlock_impl") at util/qemu-thread-posix.c:36 qemu#3 0x00005650222950ba in qemu_mutex_unlock_impl (mutex=mutex@entry=0x5650244b0240, file=file@entry=0x565022439adf "util/async.c", line=line@entry=526) at util/qemu-thread-posix.c:108 qemu#4 0x0000565022290029 in aio_context_release (ctx=ctx@entry=0x5650244b01e0) at util/async.c:526 qemu#5 0x000056502221cd08 in bdrv_can_store_new_dirty_bitmap (bs=bs@entry=0x5650244dc820, name=name@entry=0x56502481d360 "bitmap1", granularity=granularity@entry=65536, errp=errp@entry=0x7fff22831718) at block/dirty-bitmap.c:542 qemu#6 0x000056502206ae53 in qmp_block_dirty_bitmap_add (errp=0x7fff22831718, disabled=false, has_disabled=<optimized out>, persistent=<optimized out>, has_persistent=true, granularity=65536, has_granularity=<optimized out>, name=0x56502481d360 "bitmap1", node=<optimized out>) at blockdev.c:2894 qemu#7 0x000056502206ae53 in qmp_block_dirty_bitmap_add (node=<optimized out>, name=0x56502481d360 "bitmap1", has_granularity=<optimized out>, granularity=<optimized out>, has_persistent=true, persistent=<optimized out>, has_disabled=false, disabled=false, errp=0x7fff22831718) at blockdev.c:2856 qemu#8 0x00005650221847a3 in qmp_marshal_block_dirty_bitmap_add (args=<optimized out>, ret=<optimized out>, errp=0x7fff22831798) at qapi/qapi-commands-block-core.c:651 qemu#9 0x0000565022247e6c in do_qmp_dispatch (errp=0x7fff22831790, allow_oob=<optimized out>, request=<optimized out>, cmds=0x565022b32d60 <qmp_commands>) at qapi/qmp-dispatch.c:132 qemu#10 0x0000565022247e6c in qmp_dispatch (cmds=0x565022b32d60 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175 qemu#11 0x0000565022166061 in monitor_qmp_dispatch (mon=0x56502450faa0, req=<optimized out>) at monitor/qmp.c:145 qemu#12 0x00005650221666fa in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:234 qemu#13 0x000056502228f866 in aio_bh_call (bh=0x56502440eae0) at util/async.c:117 qemu#14 0x000056502228f866 in aio_bh_poll (ctx=ctx@entry=0x56502440d7a0) at util/async.c:117 qemu#15 0x0000565022292c54 in aio_dispatch (ctx=0x56502440d7a0) at util/aio-posix.c:459 qemu#16 0x000056502228f742 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260 qemu#17 0x00007f0ef5ce667d in g_main_dispatch (context=0x56502449aa40) at gmain.c:3176 qemu#18 0x00007f0ef5ce667d in g_main_context_dispatch (context=context@entry=0x56502449aa40) at gmain.c:3829 qemu#19 0x0000565022291d08 in glib_pollfds_poll () at util/main-loop.c:219 qemu#20 0x0000565022291d08 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242 qemu#21 0x0000565022291d08 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518 qemu#22 0x00005650220743c1 in main_loop () at vl.c:1828 qemu#23 0x0000565021f20a72 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504 Fix this by acquiring the AioContext at qmp_block_dirty_bitmap_add() and qmp_block_dirty_bitmap_add(). RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1782175 Signed-off-by: Sergio Lopez <slp@redhat.com>

external_snapshot_abort() calls to bdrv_set_backing_hd(), which returns state->old_bs to the main AioContext, as it's intended to be used then the BDS is going to be released. As that's not the case when aborting an external snapshot, return it to the AioContext it was before the call. This issue can be triggered by issuing a transaction with two actions, a proper blockdev-snapshot-sync and a bogus one, so the second will trigger a transaction abort. This results in a crash with an stack trace like this one: #0 0x00007fa1048b28df in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 qemu#1 0x00007fa10489ccf5 in __GI_abort () at abort.c:79 qemu#2 0x00007fa10489cbc9 in __assert_fail_base (fmt=0x7fa104a03300 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5572240b44d8 "bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)", file=0x557224014d30 "block.c", line=2240, function=<optimized out>) at assert.c:92 qemu#3 0x00007fa1048aae96 in __GI___assert_fail (assertion=assertion@entry=0x5572240b44d8 "bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)", file=file@entry=0x557224014d30 "block.c", line=line@entry=2240, function=function@entry=0x5572240b5d60 <__PRETTY_FUNCTION__.31620> "bdrv_replace_child_noperm") at assert.c:101 qemu#4 0x0000557223e631f8 in bdrv_replace_child_noperm (child=0x557225b9c980, new_bs=new_bs@entry=0x557225c42e40) at block.c:2240 qemu#5 0x0000557223e68be7 in bdrv_replace_node (from=0x557226951a60, to=0x557225c42e40, errp=0x5572247d6138 <error_abort>) at block.c:4196 qemu#6 0x0000557223d069c4 in external_snapshot_abort (common=0x557225d7e170) at blockdev.c:1731 qemu#7 0x0000557223d069c4 in external_snapshot_abort (common=0x557225d7e170) at blockdev.c:1717 qemu#8 0x0000557223d09013 in qmp_transaction (dev_list=<optimized out>, has_props=<optimized out>, props=0x557225cc7d70, errp=errp@entry=0x7ffe704c0c98) at blockdev.c:2360 qemu#9 0x0000557223e32085 in qmp_marshal_transaction (args=<optimized out>, ret=<optimized out>, errp=0x7ffe704c0d08) at qapi/qapi-commands-transaction.c:44 qemu#10 0x0000557223ee798c in do_qmp_dispatch (errp=0x7ffe704c0d00, allow_oob=<optimized out>, request=<optimized out>, cmds=0x5572247d3cc0 <qmp_commands>) at qapi/qmp-dispatch.c:132 qemu#11 0x0000557223ee798c in qmp_dispatch (cmds=0x5572247d3cc0 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175 qemu#12 0x0000557223e06141 in monitor_qmp_dispatch (mon=0x557225c69ff0, req=<optimized out>) at monitor/qmp.c:120 qemu#13 0x0000557223e0678a in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:209 qemu#14 0x0000557223f2f366 in aio_bh_call (bh=0x557225b9dc60) at util/async.c:117 qemu#15 0x0000557223f2f366 in aio_bh_poll (ctx=ctx@entry=0x557225b9c840) at util/async.c:117 qemu#16 0x0000557223f32754 in aio_dispatch (ctx=0x557225b9c840) at util/aio-posix.c:459 qemu#17 0x0000557223f2f242 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260 qemu#18 0x00007fa10913467d in g_main_dispatch (context=0x557225c28e80) at gmain.c:3176 qemu#19 0x00007fa10913467d in g_main_context_dispatch (context=context@entry=0x557225c28e80) at gmain.c:3829 qemu#20 0x0000557223f31808 in glib_pollfds_poll () at util/main-loop.c:219 qemu#21 0x0000557223f31808 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242 qemu#22 0x0000557223f31808 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518 qemu#23 0x0000557223d13201 in main_loop () at vl.c:1828 qemu#24 0x0000557223bbfb82 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504 RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1779036 Signed-off-by: Sergio Lopez <slp@redhat.com>

start vm with libvirt, when GuestOS running, enter poweroff command using the xhci keyboard, then ASAN shows memory leak stack： Direct leak of 80 byte(s) in 5 object(s) allocated from: #0 0xfffd1e6431cb in __interceptor_malloc (/lib64/libasan.so.4+0xd31cb) #1 0xfffd1e107163 in g_malloc (/lib64/libglib-2.0.so.0+0x57163) #2 0xaaad39051367 in qemu_sglist_init /qemu/dma-helpers.c:43 #3 0xaaad3947c407 in pci_dma_sglist_init /qemu/include/hw/pci/pci.h:842 #4 0xaaad3947c407 in xhci_xfer_create_sgl /qemu/hw/usb/hcd-xhci.c:1446 #5 0xaaad3947c407 in xhci_setup_packet /qemu/hw/usb/hcd-xhci.c:1618 #6 0xaaad3948625f in xhci_submit /qemu/hw/usb/hcd-xhci.c:1827 #7 0xaaad3948625f in xhci_fire_transfer /qemu/hw/usb/hcd-xhci.c:1839 #8 0xaaad3948625f in xhci_kick_epctx /qemu/hw/usb/hcd-xhci.c:1991 #9 0xaaad3948f537 in xhci_doorbell_write /qemu/hw/usb/hcd-xhci.c:3158 #10 0xaaad38bcbfc7 in memory_region_write_accessor /qemu/memory.c:483 #11 0xaaad38bc654f in access_with_adjusted_size /qemu/memory.c:544 #12 0xaaad38bd1877 in memory_region_dispatch_write /qemu/memory.c:1482 #13 0xaaad38b1c77f in flatview_write_continue /qemu/exec.c:3167 #14 0xaaad38b1ca83 in flatview_write /qemu/exec.c:3207 #15 0xaaad38b268db in address_space_write /qemu/exec.c:3297 #16 0xaaad38bf909b in kvm_cpu_exec /qemu/accel/kvm/kvm-all.c:2383 #17 0xaaad38bb063f in qemu_kvm_cpu_thread_fn /qemu/cpus.c:1246 #18 0xaaad39821c93 in qemu_thread_start /qemu/util/qemu-thread-posix.c:519 #19 0xfffd1c8378bb (/lib64/libpthread.so.0+0x78bb) #20 0xfffd1c77616b (/lib64/libc.so.6+0xd616b) Reported-by: Euler Robot <euler.robot@huawei.com> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com> Message-id: 20200110105855.81144-1-kuhn.chenqun@huawei.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

All paths that lead to bdrv_backup_top_drop(), except for the call from backup_clean(), imply that the BDS AioContext has already been acquired, so doing it there too can potentially lead to QEMU hanging on AIO_WAIT_WHILE(). An easy way to trigger this situation is by issuing a two actions transaction, with a proper and a bogus blockdev-backup, so the second one will trigger a rollback. This will trigger a hang with an stack trace like this one: #0 0x00007fb680c75016 in __GI_ppoll (fds=0x55e74580f7c0, nfds=1, timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39 qemu#1 0x000055e743386e09 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77 qemu#2 0x000055e743386e09 in qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at util/qemu-timer.c:336 qemu#3 0x000055e743388dc4 in aio_poll (ctx=0x55e7458925d0, blocking=blocking@entry=true) at util/aio-posix.c:669 qemu#4 0x000055e743305dea in bdrv_flush (bs=bs@entry=0x55e74593c0d0) at block/io.c:2878 qemu#5 0x000055e7432be58e in bdrv_close (bs=0x55e74593c0d0) at block.c:4017 qemu#6 0x000055e7432be58e in bdrv_delete (bs=<optimized out>) at block.c:4262 qemu#7 0x000055e7432be58e in bdrv_unref (bs=bs@entry=0x55e74593c0d0) at block.c:5644 qemu#8 0x000055e743316b9b in bdrv_backup_top_drop (bs=bs@entry=0x55e74593c0d0) at block/backup-top.c:273 qemu#9 0x000055e74331461f in backup_job_create (job_id=0x0, bs=bs@entry=0x55e7458d5820, target=target@entry=0x55e74589f640, speed=0, sync_mode=MIRROR_SYNC_MODE_FULL, sync_bitmap=sync_bitmap@entry=0x0, bitmap_mode=BITMAP_SYNC_MODE_ON_SUCCESS, compress=false, filter_node_name=0x0, on_source_error=BLOCKDEV_ON_ERROR_REPORT, on_target_error=BLOCKDEV_ON_ERROR_REPORT, creation_flags=0, cb=0x0, opaque=0x0, txn=0x0, errp=0x7ffddfd1efb0) at block/backup.c:478 qemu#10 0x000055e74315bc52 in do_backup_common (backup=backup@entry=0x55e746c066d0, bs=bs@entry=0x55e7458d5820, target_bs=target_bs@entry=0x55e74589f640, aio_context=aio_context@entry=0x55e7458a91e0, txn=txn@entry=0x0, errp=errp@entry=0x7ffddfd1efb0) at blockdev.c:3580 qemu#11 0x000055e74315c37c in do_blockdev_backup (backup=backup@entry=0x55e746c066d0, txn=0x0, errp=errp@entry=0x7ffddfd1efb0) at /usr/src/debug/qemu-kvm-4.2.0-2.module+el8.2.0+5135+ed3b2489.x86_64/./qapi/qapi-types-block-core.h:1492 qemu#12 0x000055e74315c449 in blockdev_backup_prepare (common=0x55e746a8de90, errp=0x7ffddfd1f018) at blockdev.c:1885 qemu#13 0x000055e743160152 in qmp_transaction (dev_list=<optimized out>, has_props=<optimized out>, props=0x55e7467fe2c0, errp=errp@entry=0x7ffddfd1f088) at blockdev.c:2340 qemu#14 0x000055e743287ff5 in qmp_marshal_transaction (args=<optimized out>, ret=<optimized out>, errp=0x7ffddfd1f0f8) at qapi/qapi-commands-transaction.c:44 qemu#15 0x000055e74333de6c in do_qmp_dispatch (errp=0x7ffddfd1f0f0, allow_oob=<optimized out>, request=<optimized out>, cmds=0x55e743c28d60 <qmp_commands>) at qapi/qmp-dispatch.c:132 qemu#16 0x000055e74333de6c in qmp_dispatch (cmds=0x55e743c28d60 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175 qemu#17 0x000055e74325c061 in monitor_qmp_dispatch (mon=0x55e745908030, req=<optimized out>) at monitor/qmp.c:145 qemu#18 0x000055e74325c6fa in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:234 qemu#19 0x000055e743385866 in aio_bh_call (bh=0x55e745807ae0) at util/async.c:117 qemu#20 0x000055e743385866 in aio_bh_poll (ctx=ctx@entry=0x55e7458067a0) at util/async.c:117 qemu#21 0x000055e743388c54 in aio_dispatch (ctx=0x55e7458067a0) at util/aio-posix.c:459 qemu#22 0x000055e743385742 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260 qemu#23 0x00007fb68543e67d in g_main_dispatch (context=0x55e745893a40) at gmain.c:3176 qemu#24 0x00007fb68543e67d in g_main_context_dispatch (context=context@entry=0x55e745893a40) at gmain.c:3829 qemu#25 0x000055e743387d08 in glib_pollfds_poll () at util/main-loop.c:219 qemu#26 0x000055e743387d08 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242 qemu#27 0x000055e743387d08 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518 qemu#28 0x000055e74316a3c1 in main_loop () at vl.c:1828 qemu#29 0x000055e743016a72 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504 Fix this by not acquiring the AioContext there, and ensuring all paths leading to it have it already acquired (backup_clean()). RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1782111 Signed-off-by: Sergio Lopez <slp@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Dirty map addition and removal functions are not acquiring to BDS AioContext, while they may call to code that expects it to be acquired. This may trigger a crash with a stack trace like this one: #0 0x00007f0ef146370f in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 qemu#1 0x00007f0ef144db25 in __GI_abort () at abort.c:79 qemu#2 0x0000565022294dce in error_exit (err=<optimized out>, msg=msg@entry=0x56502243a730 <__func__.16350> "qemu_mutex_unlock_impl") at util/qemu-thread-posix.c:36 qemu#3 0x00005650222950ba in qemu_mutex_unlock_impl (mutex=mutex@entry=0x5650244b0240, file=file@entry=0x565022439adf "util/async.c", line=line@entry=526) at util/qemu-thread-posix.c:108 qemu#4 0x0000565022290029 in aio_context_release (ctx=ctx@entry=0x5650244b01e0) at util/async.c:526 qemu#5 0x000056502221cd08 in bdrv_can_store_new_dirty_bitmap (bs=bs@entry=0x5650244dc820, name=name@entry=0x56502481d360 "bitmap1", granularity=granularity@entry=65536, errp=errp@entry=0x7fff22831718) at block/dirty-bitmap.c:542 qemu#6 0x000056502206ae53 in qmp_block_dirty_bitmap_add (errp=0x7fff22831718, disabled=false, has_disabled=<optimized out>, persistent=<optimized out>, has_persistent=true, granularity=65536, has_granularity=<optimized out>, name=0x56502481d360 "bitmap1", node=<optimized out>) at blockdev.c:2894 qemu#7 0x000056502206ae53 in qmp_block_dirty_bitmap_add (node=<optimized out>, name=0x56502481d360 "bitmap1", has_granularity=<optimized out>, granularity=<optimized out>, has_persistent=true, persistent=<optimized out>, has_disabled=false, disabled=false, errp=0x7fff22831718) at blockdev.c:2856 qemu#8 0x00005650221847a3 in qmp_marshal_block_dirty_bitmap_add (args=<optimized out>, ret=<optimized out>, errp=0x7fff22831798) at qapi/qapi-commands-block-core.c:651 qemu#9 0x0000565022247e6c in do_qmp_dispatch (errp=0x7fff22831790, allow_oob=<optimized out>, request=<optimized out>, cmds=0x565022b32d60 <qmp_commands>) at qapi/qmp-dispatch.c:132 qemu#10 0x0000565022247e6c in qmp_dispatch (cmds=0x565022b32d60 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175 qemu#11 0x0000565022166061 in monitor_qmp_dispatch (mon=0x56502450faa0, req=<optimized out>) at monitor/qmp.c:145 qemu#12 0x00005650221666fa in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:234 qemu#13 0x000056502228f866 in aio_bh_call (bh=0x56502440eae0) at util/async.c:117 qemu#14 0x000056502228f866 in aio_bh_poll (ctx=ctx@entry=0x56502440d7a0) at util/async.c:117 qemu#15 0x0000565022292c54 in aio_dispatch (ctx=0x56502440d7a0) at util/aio-posix.c:459 qemu#16 0x000056502228f742 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260 qemu#17 0x00007f0ef5ce667d in g_main_dispatch (context=0x56502449aa40) at gmain.c:3176 qemu#18 0x00007f0ef5ce667d in g_main_context_dispatch (context=context@entry=0x56502449aa40) at gmain.c:3829 qemu#19 0x0000565022291d08 in glib_pollfds_poll () at util/main-loop.c:219 qemu#20 0x0000565022291d08 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242 qemu#21 0x0000565022291d08 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518 qemu#22 0x00005650220743c1 in main_loop () at vl.c:1828 qemu#23 0x0000565021f20a72 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504 Fix this by acquiring the AioContext at qmp_block_dirty_bitmap_add() and qmp_block_dirty_bitmap_add(). RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1782175 Signed-off-by: Sergio Lopez <slp@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

external_snapshot_abort() calls to bdrv_set_backing_hd(), which returns state->old_bs to the main AioContext, as it's intended to be used then the BDS is going to be released. As that's not the case when aborting an external snapshot, return it to the AioContext it was before the call. This issue can be triggered by issuing a transaction with two actions, a proper blockdev-snapshot-sync and a bogus one, so the second will trigger a transaction abort. This results in a crash with an stack trace like this one: #0 0x00007fa1048b28df in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 qemu#1 0x00007fa10489ccf5 in __GI_abort () at abort.c:79 qemu#2 0x00007fa10489cbc9 in __assert_fail_base (fmt=0x7fa104a03300 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5572240b44d8 "bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)", file=0x557224014d30 "block.c", line=2240, function=<optimized out>) at assert.c:92 qemu#3 0x00007fa1048aae96 in __GI___assert_fail (assertion=assertion@entry=0x5572240b44d8 "bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)", file=file@entry=0x557224014d30 "block.c", line=line@entry=2240, function=function@entry=0x5572240b5d60 <__PRETTY_FUNCTION__.31620> "bdrv_replace_child_noperm") at assert.c:101 qemu#4 0x0000557223e631f8 in bdrv_replace_child_noperm (child=0x557225b9c980, new_bs=new_bs@entry=0x557225c42e40) at block.c:2240 qemu#5 0x0000557223e68be7 in bdrv_replace_node (from=0x557226951a60, to=0x557225c42e40, errp=0x5572247d6138 <error_abort>) at block.c:4196 qemu#6 0x0000557223d069c4 in external_snapshot_abort (common=0x557225d7e170) at blockdev.c:1731 qemu#7 0x0000557223d069c4 in external_snapshot_abort (common=0x557225d7e170) at blockdev.c:1717 qemu#8 0x0000557223d09013 in qmp_transaction (dev_list=<optimized out>, has_props=<optimized out>, props=0x557225cc7d70, errp=errp@entry=0x7ffe704c0c98) at blockdev.c:2360 qemu#9 0x0000557223e32085 in qmp_marshal_transaction (args=<optimized out>, ret=<optimized out>, errp=0x7ffe704c0d08) at qapi/qapi-commands-transaction.c:44 qemu#10 0x0000557223ee798c in do_qmp_dispatch (errp=0x7ffe704c0d00, allow_oob=<optimized out>, request=<optimized out>, cmds=0x5572247d3cc0 <qmp_commands>) at qapi/qmp-dispatch.c:132 qemu#11 0x0000557223ee798c in qmp_dispatch (cmds=0x5572247d3cc0 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175 qemu#12 0x0000557223e06141 in monitor_qmp_dispatch (mon=0x557225c69ff0, req=<optimized out>) at monitor/qmp.c:120 qemu#13 0x0000557223e0678a in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:209 qemu#14 0x0000557223f2f366 in aio_bh_call (bh=0x557225b9dc60) at util/async.c:117 qemu#15 0x0000557223f2f366 in aio_bh_poll (ctx=ctx@entry=0x557225b9c840) at util/async.c:117 qemu#16 0x0000557223f32754 in aio_dispatch (ctx=0x557225b9c840) at util/aio-posix.c:459 qemu#17 0x0000557223f2f242 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260 qemu#18 0x00007fa10913467d in g_main_dispatch (context=0x557225c28e80) at gmain.c:3176 qemu#19 0x00007fa10913467d in g_main_context_dispatch (context=context@entry=0x557225c28e80) at gmain.c:3829 qemu#20 0x0000557223f31808 in glib_pollfds_poll () at util/main-loop.c:219 qemu#21 0x0000557223f31808 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242 qemu#22 0x0000557223f31808 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518 qemu#23 0x0000557223d13201 in main_loop () at vl.c:1828 qemu#24 0x0000557223bbfb82 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504 RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1779036 Signed-off-by: Sergio Lopez <slp@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Coverity reports: *** CID 1419387: Memory - illegal accesses (OVERRUN) /hw/hppa/dino.c: 267 in dino_chip_read_with_attrs() 261 val = s->ilr & s->imr & s->icr; 262 break; 263 case DINO_TOC_ADDR: 264 val = s->toc_addr; 265 break; 266 case DINO_GMASK ... DINO_TLTIM: >>> CID 1419387: Memory - illegal accesses (OVERRUN) >>> Overrunning array "s->reg800" of 12 4-byte elements at element index 12 (byte offset 48) using index "(addr - 2048UL) / 4UL" (which evaluates to 12). 267 val = s->reg800[(addr - DINO_GMASK) / 4]; 268 if (addr == DINO_PAMR) { 269 val &= ~0x01; /* LSB is hardwired to 0 */ 270 } 271 if (addr == DINO_MLTIM) { 272 val &= ~0x07; /* 3 LSB are hardwired to 0 */ *** CID 1419393: Memory - corruptions (OVERRUN) /hw/hppa/dino.c: 363 in dino_chip_write_with_attrs() 357 /* These registers are read-only. */ 358 break; 359 360 case DINO_GMASK ... DINO_TLTIM: 361 i = (addr - DINO_GMASK) / 4; 362 val &= reg800_keep_bits[i]; >>> CID 1419393: Memory - corruptions (OVERRUN) >>> Overrunning array "s->reg800" of 12 4-byte elements at element index 12 (byte offset 48) using index "i" (which evaluates to 12). 363 s->reg800[i] = val; 364 break; 365 366 default: 367 /* Controlled by dino_chip_mem_valid above. */ 368 g_assert_not_reached(); *** CID 1419394: Memory - illegal accesses (OVERRUN) /hw/hppa/dino.c: 362 in dino_chip_write_with_attrs() 356 case DINO_IRR1: 357 /* These registers are read-only. */ 358 break; 359 360 case DINO_GMASK ... DINO_TLTIM: 361 i = (addr - DINO_GMASK) / 4; >>> CID 1419394: Memory - illegal accesses (OVERRUN) >>> Overrunning array "reg800_keep_bits" of 12 4-byte elements at element index 12 (byte offset 48) using index "i" (which evaluates to 12). 362 val &= reg800_keep_bits[i]; 363 s->reg800[i] = val; 364 break; 365 366 default: 367 /* Controlled by dino_chip_mem_valid above. */ Indeed the array should contain 13 entries, the undocumented register 0x82c is missing. Fix by increasing the array size and adding the missing register. CID 1419387 can be verified with: $ echo x 0xfff80830 | hppa-softmmu/qemu-system-hppa -S -monitor stdio -display none QEMU 4.2.50 monitor - type 'help' for more information (qemu) x 0xfff80830 qemu/hw/hppa/dino.c:267:15: runtime error: index 12 out of bounds for type 'uint32_t [12]' SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /home/phil/source/qemu/hw/hppa/dino.c:267:15 in 00000000fff80830: 0x00000000 and CID 1419393/1419394 with: $ echo writeb 0xfff80830 0x69 \ | hppa-softmmu/qemu-system-hppa -S -accel qtest -qtest stdio -display none [I 1581634452.654113] OPENED [R +4.105415] writeb 0xfff80830 0x69 qemu/hw/hppa/dino.c:362:16: runtime error: index 12 out of bounds for type 'const uint32_t [12]' SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior qemu/hw/hppa/dino.c:362:16 in ================================================================= ==29607==ERROR: AddressSanitizer: global-buffer-overflow on address 0x5577dae32f30 at pc 0x5577d93f2463 bp 0x7ffd97ea11b0 sp 0x7ffd97ea11a8 READ of size 4 at 0x5577dae32f30 thread T0 #0 0x5577d93f2462 in dino_chip_write_with_attrs qemu/hw/hppa/dino.c:362:16 #1 0x5577d9025664 in memory_region_write_with_attrs_accessor qemu/memory.c:503:12 #2 0x5577d9024920 in access_with_adjusted_size qemu/memory.c:539:18 #3 0x5577d9023608 in memory_region_dispatch_write qemu/memory.c:1482:13 qemu#4 0x5577d8e3177a in flatview_write_continue qemu/exec.c:3166:23 qemu#5 0x5577d8e20357 in flatview_write qemu/exec.c:3206:14 qemu#6 0x5577d8e1fef4 in address_space_write qemu/exec.c:3296:18 qemu#7 0x5577d8e20693 in address_space_rw qemu/exec.c:3306:16 qemu#8 0x5577d9011595 in qtest_process_command qemu/qtest.c:432:13 qemu#9 0x5577d900d19f in qtest_process_inbuf qemu/qtest.c:705:9 qemu#10 0x5577d900ca22 in qtest_read qemu/qtest.c:717:5 qemu#11 0x5577da8c4254 in qemu_chr_be_write_impl qemu/chardev/char.c:183:9 qemu#12 0x5577da8c430c in qemu_chr_be_write qemu/chardev/char.c:195:9 qemu#13 0x5577da8cf587 in fd_chr_read qemu/chardev/char-fd.c:68:9 qemu#14 0x5577da9836cd in qio_channel_fd_source_dispatch qemu/io/channel-watch.c:84:12 qemu#15 0x7faf44509ecc in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x4fecc) qemu#16 0x5577dab75f96 in glib_pollfds_poll qemu/util/main-loop.c:219:9 qemu#17 0x5577dab74797 in os_host_main_loop_wait qemu/util/main-loop.c:242:5 qemu#18 0x5577dab7435a in main_loop_wait qemu/util/main-loop.c:518:11 qemu#19 0x5577d9514eb3 in main_loop qemu/vl.c:1682:9 qemu#20 0x5577d950699d in main qemu/vl.c:4450:5 qemu#21 0x7faf41a87f42 in __libc_start_main (/lib64/libc.so.6+0x23f42) qemu#22 0x5577d8cd4d4d in _start (qemu/build/sanitizer/hppa-softmmu/qemu-system-hppa+0x1256d4d) 0x5577dae32f30 is located 0 bytes to the right of global variable 'reg800_keep_bits' defined in 'qemu/hw/hppa/dino.c:87:23' (0x5577dae32f00) of size 48 SUMMARY: AddressSanitizer: global-buffer-overflow qemu/hw/hppa/dino.c:362:16 in dino_chip_write_with_attrs Shadow bytes around the buggy address: 0x0aaf7b5be590: 00 f9 f9 f9 f9 f9 f9 f9 00 02 f9 f9 f9 f9 f9 f9 0x0aaf7b5be5a0: 07 f9 f9 f9 f9 f9 f9 f9 07 f9 f9 f9 f9 f9 f9 f9 0x0aaf7b5be5b0: 07 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00 0x0aaf7b5be5c0: 00 00 00 02 f9 f9 f9 f9 00 00 00 00 00 00 00 00 0x0aaf7b5be5d0: 00 00 00 00 00 00 00 00 00 00 00 03 f9 f9 f9 f9 =>0x0aaf7b5be5e0: 00 00 00 00 00 00[f9]f9 f9 f9 f9 f9 00 00 00 00 0x0aaf7b5be5f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0aaf7b5be600: 00 00 01 f9 f9 f9 f9 f9 00 00 00 00 07 f9 f9 f9 0x0aaf7b5be610: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00 0x0aaf7b5be620: 00 00 00 05 f9 f9 f9 f9 00 00 00 00 07 f9 f9 f9 0x0aaf7b5be630: f9 f9 f9 f9 00 00 f9 f9 f9 f9 f9 f9 07 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 ==29607==ABORTING Fixes: Covertiy CID 1419387 / 1419393 / 1419394 (commit 1809259) Acked-by: Helge Deller <deller@gmx.de> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20200218063355.18577-3-f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Similar to other virtio device(https://patchwork.kernel.org/patch/11399237/), virtio queues forgot to delete in unrealize, and aslo error path in realize, this patch fix these memleaks, the leak stack is as follow: Direct leak of 57344 byte(s) in 1 object(s) allocated from: #0 0x7f15784fb970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970) #1 0x7f157790849d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d) #2 0x55587a1bf859 in virtio_add_queue /mnt/sdb/qemu-new/qemu_test/qemu/hw/virtio/virtio.c:2333 #3 0x55587a2071d5 in vuf_device_realize /mnt/sdb/qemu-new/qemu_test/qemu/hw/virtio/vhost-user-fs.c:212 #4 0x55587a1ae360 in virtio_device_realize /mnt/sdb/qemu-new/qemu_test/qemu/hw/virtio/virtio.c:3531 #5 0x55587a63fb7b in device_set_realized /mnt/sdb/qemu-new/qemu_test/qemu/hw/core/qdev.c:891 #6 0x55587acf03f5 in property_set_bool /mnt/sdb/qemu-new/qemu_test/qemu/qom/object.c:2238 #7 0x55587acfce0d in object_property_set_qobject /mnt/sdb/qemu-new/qemu_test/qemu/qom/qom-qobject.c:26 #8 0x55587acf5c8c in object_property_set_bool /mnt/sdb/qemu-new/qemu_test/qemu/qom/object.c:1390 #9 0x55587a8e22a2 in pci_qdev_realize /mnt/sdb/qemu-new/qemu_test/qemu/hw/pci/pci.c:2095 #10 0x55587a63fb7b in device_set_realized /mnt/sdb/qemu-new/qemu_test/qemu/hw/core/qdev.c:891 #11 0x55587acf03f5 in property_set_bool /mnt/sdb/qemu-new/qemu_test/qemu/qom/object.c:2238 #12 0x55587acfce0d in object_property_set_qobject /mnt/sdb/qemu-new/qemu_test/qemu/qom/qom-qobject.c:26 #13 0x55587acf5c8c in object_property_set_bool /mnt/sdb/qemu-new/qemu_test/qemu/qom/object.c:1390 #14 0x55587a496d65 in qdev_device_add /mnt/sdb/qemu-new/qemu_test/qemu/qdev-monitor.c:679 Reported-by: Euler Robot <euler.robot@huawei.com> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200225075554.10835-2-pannengyuan@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

The virtqueue code sets up MemoryRegionCaches to access the virtqueue guest RAM data structures. The code currently assumes that VRingMemoryRegionCaches is initialized before device emulation code accesses the virtqueue. An assertion will fail in vring_get_region_caches() when this is not true. Device fuzzing found a case where this assumption is false (see below). Virtqueue guest RAM addresses can also be changed from a vCPU thread while an IOThread is accessing the virtqueue. This breaks the same assumption but this time the caches could become invalid partway through the virtqueue code. The code fetches the caches RCU pointer multiple times so we will need to validate the pointer every time it is fetched. Add checks each time we call vring_get_region_caches() and treat invalid caches as a nop: memory stores are ignored and memory reads return 0. The fuzz test failure is as follows: $ qemu -M pc -device virtio-blk-pci,id=drv0,drive=drive0,addr=4.0 \ -drive if=none,id=drive0,file=null-co://,format=raw,auto-read-only=off \ -drive if=none,id=drive1,file=null-co://,file.read-zeroes=on,format=raw \ -display none \ -qtest stdio endianness outl 0xcf8 0x80002020 outl 0xcfc 0xe0000000 outl 0xcf8 0x80002004 outw 0xcfc 0x7 write 0xe0000000 0x24 0x00ffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffab5cffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffab0000000001 inb 0x4 writew 0xe000001c 0x1 write 0xe0000014 0x1 0x0d The following error message is produced: qemu-system-x86_64: /home/stefanha/qemu/hw/virtio/virtio.c:286: vring_get_region_caches: Assertion `caches != NULL' failed. The backtrace looks like this: #0 0x00007ffff5520625 in raise () at /lib64/libc.so.6 #1 0x00007ffff55098d9 in abort () at /lib64/libc.so.6 #2 0x00007ffff55097a9 in _nl_load_domain.cold () at /lib64/libc.so.6 #3 0x00007ffff5518a66 in annobin_assert.c_end () at /lib64/libc.so.6 #4 0x00005555559073da in vring_get_region_caches (vq=<optimized out>) at qemu/hw/virtio/virtio.c:286 #5 vring_get_region_caches (vq=<optimized out>) at qemu/hw/virtio/virtio.c:283 #6 0x000055555590818d in vring_used_flags_set_bit (mask=1, vq=0x5555575ceea0) at qemu/hw/virtio/virtio.c:398 #7 virtio_queue_split_set_notification (enable=0, vq=0x5555575ceea0) at qemu/hw/virtio/virtio.c:398 #8 virtio_queue_set_notification (vq=vq@entry=0x5555575ceea0, enable=enable@entry=0) at qemu/hw/virtio/virtio.c:451 #9 0x0000555555908512 in virtio_queue_set_notification (vq=vq@entry=0x5555575ceea0, enable=enable@entry=0) at qemu/hw/virtio/virtio.c:444 #10 0x00005555558c697a in virtio_blk_handle_vq (s=0x5555575c57e0, vq=0x5555575ceea0) at qemu/hw/block/virtio-blk.c:775 #11 0x0000555555907836 in virtio_queue_notify_aio_vq (vq=0x5555575ceea0) at qemu/hw/virtio/virtio.c:2244 #12 0x0000555555cb5dd7 in aio_dispatch_handlers (ctx=ctx@entry=0x55555671a420) at util/aio-posix.c:429 #13 0x0000555555cb67a8 in aio_dispatch (ctx=0x55555671a420) at util/aio-posix.c:460 #14 0x0000555555cb307e in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260 #15 0x00007ffff7bbc510 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0 #16 0x0000555555cb5848 in glib_pollfds_poll () at util/main-loop.c:219 #17 os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242 #18 main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518 #19 0x00005555559b20c9 in main_loop () at vl.c:1683 #20 0x0000555555838115 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4441 Reported-by: Alexander Bulekov <alxndr@bu.edu> Cc: Michael Tsirkin <mst@redhat.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200207104619.164892-1-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

'crypto_opts' forgot to free in qcow2_close(), this patch fix the bellow leak stack: Direct leak of 24 byte(s) in 1 object(s) allocated from: #0 0x7f0edd81f970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970) #1 0x7f0edc6d149d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d) #2 0x55d7eaede63d in qobject_input_start_struct /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qobject-input-visitor.c:295 #3 0x55d7eaed78b8 in visit_start_struct /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qapi-visit-core.c:49 #4 0x55d7eaf5140b in visit_type_QCryptoBlockOpenOptions qapi/qapi-visit-crypto.c:290 #5 0x55d7eae43af3 in block_crypto_open_opts_init /mnt/sdb/qemu-new/qemu_test/qemu/block/crypto.c:163 #6 0x55d7eacd2924 in qcow2_update_options_prepare /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1148 #7 0x55d7eacd33f7 in qcow2_update_options /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1232 #8 0x55d7eacd9680 in qcow2_do_open /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1512 #9 0x55d7eacdc55e in qcow2_open_entry /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1792 #10 0x55d7eacdc8fe in qcow2_open /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1819 #11 0x55d7eac3742d in bdrv_open_driver /mnt/sdb/qemu-new/qemu_test/qemu/block.c:1317 #12 0x55d7eac3e990 in bdrv_open_common /mnt/sdb/qemu-new/qemu_test/qemu/block.c:1575 #13 0x55d7eac4442c in bdrv_open_inherit /mnt/sdb/qemu-new/qemu_test/qemu/block.c:3126 #14 0x55d7eac45c3f in bdrv_open /mnt/sdb/qemu-new/qemu_test/qemu/block.c:3219 #15 0x55d7ead8e8a4 in blk_new_open /mnt/sdb/qemu-new/qemu_test/qemu/block/block-backend.c:397 #16 0x55d7eacde74c in qcow2_co_create /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:3534 #17 0x55d7eacdfa6d in qcow2_co_create_opts /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:3668 #18 0x55d7eac1c678 in bdrv_create_co_entry /mnt/sdb/qemu-new/qemu_test/qemu/block.c:485 #19 0x55d7eb0024d2 in coroutine_trampoline /mnt/sdb/qemu-new/qemu_test/qemu/util/coroutine-ucontext.c:115 Reported-by: Euler Robot <euler.robot@huawei.com> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200227012950.12256-2-pannengyuan@huawei.com> Signed-off-by: Max Reitz <mreitz@redhat.com>

There is a use-after-free possible: bdrv_unref_child() leaves bs->backing freed but not NULL. bdrv_attach_child may produce nested polling loop due to drain, than access of freed pointer is possible. I've produced the following crash on 30 iotest with modified code. It does not reproduce on master, but still seems possible: #0 __strcmp_avx2 () at /lib64/libc.so.6 #1 bdrv_backing_overridden (bs=0x55c9d3cc2060) at block.c:6350 #2 bdrv_refresh_filename (bs=0x55c9d3cc2060) at block.c:6404 #3 bdrv_backing_attach (c=0x55c9d48e5520) at block.c:1063 #4 bdrv_replace_child_noperm (child=child@entry=0x55c9d48e5520, new_bs=new_bs@entry=0x55c9d3cc2060) at block.c:2290 #5 bdrv_replace_child (child=child@entry=0x55c9d48e5520, new_bs=new_bs@entry=0x55c9d3cc2060) at block.c:2320 #6 bdrv_root_attach_child (child_bs=child_bs@entry=0x55c9d3cc2060, child_name=child_name@entry=0x55c9d241d478 "backing", child_role=child_role@entry=0x55c9d26ecee0 <child_backing>, ctx=<optimized out>, perm=<optimized out>, shared_perm=21, opaque=0x55c9d3c5a3d0, errp=0x7ffd117108e0) at block.c:2424 #7 bdrv_attach_child (parent_bs=parent_bs@entry=0x55c9d3c5a3d0, child_bs=child_bs@entry=0x55c9d3cc2060, child_name=child_name@entry=0x55c9d241d478 "backing", child_role=child_role@entry=0x55c9d26ecee0 <child_backing>, errp=errp@entry=0x7ffd117108e0) at block.c:5876 #8 in bdrv_set_backing_hd (bs=bs@entry=0x55c9d3c5a3d0, backing_hd=backing_hd@entry=0x55c9d3cc2060, errp=errp@entry=0x7ffd117108e0) at block.c:2576 #9 stream_prepare (job=0x55c9d49d84a0) at block/stream.c:150 #10 job_prepare (job=0x55c9d49d84a0) at job.c:761 #11 job_txn_apply (txn=<optimized out>, fn=<optimized out>) at job.c:145 #12 job_do_finalize (job=0x55c9d49d84a0) at job.c:778 #13 job_completed_txn_success (job=0x55c9d49d84a0) at job.c:832 #14 job_completed (job=0x55c9d49d84a0) at job.c:845 #15 job_completed (job=0x55c9d49d84a0) at job.c:836 #16 job_exit (opaque=0x55c9d49d84a0) at job.c:864 #17 aio_bh_call (bh=0x55c9d471a160) at util/async.c:117 #18 aio_bh_poll (ctx=ctx@entry=0x55c9d3c46720) at util/async.c:117 #19 aio_poll (ctx=ctx@entry=0x55c9d3c46720, blocking=blocking@entry=true) at util/aio-posix.c:728 #20 bdrv_parent_drained_begin_single (poll=true, c=0x55c9d3d558f0) at block/io.c:121 #21 bdrv_parent_drained_begin_single (c=c@entry=0x55c9d3d558f0, poll=poll@entry=true) at block/io.c:114 #22 bdrv_replace_child_noperm (child=child@entry=0x55c9d3d558f0, new_bs=new_bs@entry=0x55c9d3d27300) at block.c:2258 #23 bdrv_replace_child (child=child@entry=0x55c9d3d558f0, new_bs=new_bs@entry=0x55c9d3d27300) at block.c:2320 #24 bdrv_root_attach_child (child_bs=child_bs@entry=0x55c9d3d27300, child_name=child_name@entry=0x55c9d241d478 "backing", child_role=child_role@entry=0x55c9d26ecee0 <child_backing>, ctx=<optimized out>, perm=<optimized out>, shared_perm=21, opaque=0x55c9d3cc2060, errp=0x7ffd11710c60) at block.c:2424 #25 bdrv_attach_child (parent_bs=parent_bs@entry=0x55c9d3cc2060, child_bs=child_bs@entry=0x55c9d3d27300, child_name=child_name@entry=0x55c9d241d478 "backing", child_role=child_role@entry=0x55c9d26ecee0 <child_backing>, errp=errp@entry=0x7ffd11710c60) at block.c:5876 #26 bdrv_set_backing_hd (bs=bs@entry=0x55c9d3cc2060, backing_hd=backing_hd@entry=0x55c9d3d27300, errp=errp@entry=0x7ffd11710c60) at block.c:2576 #27 stream_prepare (job=0x55c9d495ead0) at block/stream.c:150 ... Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200316060631.30052-2-vsementsov@virtuozzo.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>

repo-lockdown · 2020-04-08T01:10:46Z

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twocode closed this Aug 26, 2014

lalrae pushed a commit to lalrae/qemu that referenced this pull request Dec 17, 2014

Merge pull request qemu#14 from yongbok/p5600-mips32r5-PRIP3

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emaste pushed a commit to emaste/qemu that referenced this pull request Apr 14, 2016

Merge pull request qemu#14 from cognet/bsd-user

763770c

Revamp the excluvise operation mechanism a bit, taking into account t…

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FPMaxNormal should be returned instead of FPInfinity vcvt[t|b] instructions (to half precision) when roundingMode is round-to-zero. #14

FPMaxNormal should be returned instead of FPInfinity vcvt[t|b] instructions (to half precision) when roundingMode is round-to-zero. #14

twocode commented Aug 26, 2014

twocode commented Aug 26, 2014

repo-lockdown bot commented Apr 8, 2020

FPMaxNormal should be returned instead of FPInfinity vcvt[t|b] instructions (to half precision) when roundingMode is round-to-zero. #14

FPMaxNormal should be returned instead of FPInfinity vcvt[t|b] instructions (to half precision) when roundingMode is round-to-zero. #14

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twocode commented Aug 26, 2014

twocode commented Aug 26, 2014

repo-lockdown bot commented Apr 8, 2020