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Permissive mode #17

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l0kod opened this issue Jan 29, 2024 · 1 comment
Open

Permissive mode #17

l0kod opened this issue Jan 29, 2024 · 1 comment
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enhancement New feature or request

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@l0kod
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l0kod commented Jan 29, 2024 •
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Before enforcing a sandbox on a fleet with potential different configurations and states, it would be useful to know whether a restriction would have an effect on legitimate use cases. By being able to have a permissive/not-enforcing mode and thanks to #3, telemetry can inform us of all access requests that would have been denied. We can then improve the sandbox configuration and get guarantees that it will not break current workstream.

This should be configurable with a new LANDLOCK_RESTRICT_SELF_PERMISSIVE flag passed to landlock_restrict_self(). Of course, this flag must only apply to the new domain layer, the inherited restrictions and the future nested restrictions will still be enforced.
@l0kod l0kod added the enhancement New feature or request label Jan 29, 2024
@l0kod l0kod added this to Landlock Feb 1, 2024
@l0kod l0kod moved this to Ready in Landlock Feb 1, 2024
@l0kod l0kod moved this from Ready to Backlog in Landlock Feb 1, 2024
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l0kod commented Feb 21, 2024

Related to landlock-lsm/rust-landlock#36, but this would be implemented kernel-side. Both implementation are valuables and complementary for different use cases:

  • user space libraries: debugging, testing and telemetry for (unprivileged) app developers;
  • kernel audit: debugging, testing and telemetry for system administrators.

l0kod pushed a commit that referenced this issue Sep 9, 2024
@superjamie @gregkh
ethtool: check device is present when getting link settings
842a40c 
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
l0kod pushed a commit that referenced this issue Dec 16, 2024
@lategoodbye @gregkh
mailbox: bcm2835: Fix timeout during suspend mode
32ee788 
[ Upstream commit dc09f00 ]

During noirq suspend phase the Raspberry Pi power driver suffer of
firmware property timeouts. The reason is that the IRQ of the underlying
BCM2835 mailbox is disabled and rpi_firmware_property_list() will always
run into a timeout [1].

Since the VideoCore side isn't consider as a wakeup source, set the
IRQF_NO_SUSPEND flag for the mailbox IRQ in order to keep it enabled
during suspend-resume cycle.

[1]
PM: late suspend of devices complete after 1.754 msecs
WARNING: CPU: 0 PID: 438 at drivers/firmware/raspberrypi.c:128
 rpi_firmware_property_list+0x204/0x22c
Firmware transaction 0x00028001 timeout
Modules linked in:
CPU: 0 PID: 438 Comm: bash Tainted: G         C         6.9.3-dirty #17
Hardware name: BCM2835
Call trace:
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x34/0x44
dump_stack_lvl from __warn+0x88/0xec
__warn from warn_slowpath_fmt+0x7c/0xb0
warn_slowpath_fmt from rpi_firmware_property_list+0x204/0x22c
rpi_firmware_property_list from rpi_firmware_property+0x68/0x8c
rpi_firmware_property from rpi_firmware_set_power+0x54/0xc0
rpi_firmware_set_power from _genpd_power_off+0xe4/0x148
_genpd_power_off from genpd_sync_power_off+0x7c/0x11c
genpd_sync_power_off from genpd_finish_suspend+0xcc/0xe0
genpd_finish_suspend from dpm_run_callback+0x78/0xd0
dpm_run_callback from device_suspend_noirq+0xc0/0x238
device_suspend_noirq from dpm_suspend_noirq+0xb0/0x168
dpm_suspend_noirq from suspend_devices_and_enter+0x1b8/0x5ac
suspend_devices_and_enter from pm_suspend+0x254/0x2e4
pm_suspend from state_store+0xa8/0xd4
state_store from kernfs_fop_write_iter+0x154/0x1a0
kernfs_fop_write_iter from vfs_write+0x12c/0x184
vfs_write from ksys_write+0x78/0xc0
ksys_write from ret_fast_syscall+0x0/0x54
Exception stack(0xcc93dfa8 to 0xcc93dff0)
[...]
PM: noirq suspend of devices complete after 3095.584 msecs

Link: raspberrypi/firmware#1894
Fixes: 0bae6af ("mailbox: Enable BCM2835 mailbox support")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
l0kod pushed a commit that referenced this issue Dec 16, 2024
@gregkh
brd: defer automatic disk creation until module initialization succeeds
41219c1 
[ Upstream commit 826cc42 ]

My colleague Wupeng found the following problems during fault injection:

BUG: unable to handle page fault for address: fffffbfff809d073
PGD 6e648067 P4D 123ec8067 PUD 123ec4067 PMD 100e38067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 5 UID: 0 PID: 755 Comm: modprobe Not tainted 6.12.0-rc3+ #17
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:__asan_load8+0x4c/0xa0
...
Call Trace:
 <TASK>
 blkdev_put_whole+0x41/0x70
 bdev_release+0x1a3/0x250
 blkdev_release+0x11/0x20
 __fput+0x1d7/0x4a0
 task_work_run+0xfc/0x180
 syscall_exit_to_user_mode+0x1de/0x1f0
 do_syscall_64+0x6b/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

loop_init() is calling loop_add() after __register_blkdev() succeeds and
is ignoring disk_add() failure from loop_add(), for loop_add() failure
is not fatal and successfully created disks are already visible to
bdev_open().

brd_init() is currently calling brd_alloc() before __register_blkdev()
succeeds and is releasing successfully created disks when brd_init()
returns an error. This can cause UAF for the latter two case:

case 1:
    T1:
modprobe brd
  brd_init
    brd_alloc(0) // success
      add_disk
        disk_scan_partitions
          bdev_file_open_by_dev // alloc file
          fput // won't free until back to userspace
    brd_alloc(1) // failed since mem alloc error inject
  // error path for modprobe will release code segment
  // back to userspace
  __fput
    blkdev_release
      bdev_release
        blkdev_put_whole
          bdev->bd_disk->fops->release // fops is freed now, UAF!

case 2:
    T1:                            T2:
modprobe brd
  brd_init
    brd_alloc(0) // success
                                   open(/dev/ram0)
    brd_alloc(1) // fail
  // error path for modprobe

                                   close(/dev/ram0)
                                   ...
                                   /* UAF! */
                                   bdev->bd_disk->fops->release

Fix this problem by following what loop_init() does. Besides,
reintroduce brd_devices_mutex to help serialize modifications to
brd_list.

Fixes: 7f9b348 ("brd: convert to blk_alloc_disk/blk_cleanup_disk")
Reported-by: Wupeng Ma <mawupeng1@huawei.com>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241030034914.907829-1-yangerkun@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
l0kod pushed a commit that referenced this issue Dec 16, 2024
@lategoodbye @gregkh
mailbox: bcm2835: Fix timeout during suspend mode
e65a9af 
[ Upstream commit dc09f00 ]

During noirq suspend phase the Raspberry Pi power driver suffer of
firmware property timeouts. The reason is that the IRQ of the underlying
BCM2835 mailbox is disabled and rpi_firmware_property_list() will always
run into a timeout [1].

Since the VideoCore side isn't consider as a wakeup source, set the
IRQF_NO_SUSPEND flag for the mailbox IRQ in order to keep it enabled
during suspend-resume cycle.

[1]
PM: late suspend of devices complete after 1.754 msecs
WARNING: CPU: 0 PID: 438 at drivers/firmware/raspberrypi.c:128
 rpi_firmware_property_list+0x204/0x22c
Firmware transaction 0x00028001 timeout
Modules linked in:
CPU: 0 PID: 438 Comm: bash Tainted: G         C         6.9.3-dirty #17
Hardware name: BCM2835
Call trace:
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x34/0x44
dump_stack_lvl from __warn+0x88/0xec
__warn from warn_slowpath_fmt+0x7c/0xb0
warn_slowpath_fmt from rpi_firmware_property_list+0x204/0x22c
rpi_firmware_property_list from rpi_firmware_property+0x68/0x8c
rpi_firmware_property from rpi_firmware_set_power+0x54/0xc0
rpi_firmware_set_power from _genpd_power_off+0xe4/0x148
_genpd_power_off from genpd_sync_power_off+0x7c/0x11c
genpd_sync_power_off from genpd_finish_suspend+0xcc/0xe0
genpd_finish_suspend from dpm_run_callback+0x78/0xd0
dpm_run_callback from device_suspend_noirq+0xc0/0x238
device_suspend_noirq from dpm_suspend_noirq+0xb0/0x168
dpm_suspend_noirq from suspend_devices_and_enter+0x1b8/0x5ac
suspend_devices_and_enter from pm_suspend+0x254/0x2e4
pm_suspend from state_store+0xa8/0xd4
state_store from kernfs_fop_write_iter+0x154/0x1a0
kernfs_fop_write_iter from vfs_write+0x12c/0x184
vfs_write from ksys_write+0x78/0xc0
ksys_write from ret_fast_syscall+0x0/0x54
Exception stack(0xcc93dfa8 to 0xcc93dff0)
[...]
PM: noirq suspend of devices complete after 3095.584 msecs

Link: raspberrypi/firmware#1894
Fixes: 0bae6af ("mailbox: Enable BCM2835 mailbox support")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
l0kod pushed a commit that referenced this issue Dec 16, 2024
@namhyung @gregkh
perf report: Fix segfault when 'sym' sort key is not used
e34ddcc 
commit 9af2efe upstream.

The fields in the hist_entry are filled on-demand which means they only
have meaningful values when relevant sort keys are used.

So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in
the hist entry can be garbage.  So it shouldn't access it
unconditionally.

I got a segfault, when I wanted to see cgroup profiles.

  $ sudo perf record -a --all-cgroups --synth=cgroup true

  $ sudo perf report -s cgroup

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  48		return RC_CHK_ACCESS(map)->dso;
  (gdb) bt
  #0  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  #1  0x00005555557aa39b in map__load (map=0x0) at util/map.c:344
  #2  0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385
  #3  0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true)
      at util/hist.c:644
  #4  0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761
  #5  0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779
  #6  0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015
  #7  0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0)
      at util/hist.c:1260
  #8  0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0,
      machine=0x5555560388e8) at builtin-report.c:334
  #9  0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232
  #10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271
  #11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0,
      file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354
  #12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132
  #13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245
  #14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324
  #15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342
  #16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60)
      at util/session.c:780
  #17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688,
      file_path=0x555556038ff0 "perf.data") at util/session.c:1406

As you can see the entry->ms.map was NULL even if he->ms.map has a
value.  This is because 'sym' sort key is not given, so it cannot assume
whether he->ms.sym and entry->ms.sym is the same.  I only checked the
'sym' sort key here as it implies 'dso' behavior (so maps are the same).

Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Matt Fleming <matt@readmodwrite.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240826221045.1202305-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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