| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
fuse: missing copy_finish in fuse-over-io-uring argument copies
Fix a possible reference count leak of payload pages during
fuse argument copies.
[Joanne: simplified error cleanup] |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid updating zero-sized extent in extent cache
As syzbot reported:
F2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0]
------------[ cut here ]------------
kernel BUG at fs/f2fs/extent_cache.c:678!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678
Call Trace:
<TASK>
f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085
f2fs_do_zero_range fs/f2fs/file.c:1657 [inline]
f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737
f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030
vfs_fallocate+0x669/0x7e0 fs/open.c:342
ioctl_preallocate fs/ioctl.c:289 [inline]
file_ioctl+0x611/0x780 fs/ioctl.c:-1
do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576
__do_sys_ioctl fs/ioctl.c:595 [inline]
__se_sys_ioctl+0x82/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f07bc58eec9
In error path of f2fs_zero_range(), it may add a zero-sized extent
into extent cache, it should be avoided. |
| In the Linux kernel, the following vulnerability has been resolved:
char: applicom: fix NULL pointer dereference in ac_ioctl
Discovered by Atuin - Automated Vulnerability Discovery Engine.
In ac_ioctl, the validation of IndexCard and the check for a valid
RamIO pointer are skipped when cmd is 6. However, the function
unconditionally executes readb(apbs[IndexCard].RamIO + VERS) at the
end.
If cmd is 6, IndexCard may reference a board that does not exist
(where RamIO is NULL), leading to a NULL pointer dereference.
Fix this by skipping the readb access when cmd is 6, as this
command is a global information query and does not target a specific
board context. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Limit num_syncs to prevent oversized allocations
The exec and vm_bind ioctl allow userspace to specify an arbitrary
num_syncs value. Without bounds checking, a very large num_syncs
can force an excessively large allocation, leading to kernel warnings
from the page allocator as below.
Introduce DRM_XE_MAX_SYNCS (set to 1024) and reject any request
exceeding this limit.
"
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1217 at mm/page_alloc.c:5124 __alloc_frozen_pages_noprof+0x2f8/0x2180 mm/page_alloc.c:5124
...
Call Trace:
<TASK>
alloc_pages_mpol+0xe4/0x330 mm/mempolicy.c:2416
___kmalloc_large_node+0xd8/0x110 mm/slub.c:4317
__kmalloc_large_node_noprof+0x18/0xe0 mm/slub.c:4348
__do_kmalloc_node mm/slub.c:4364 [inline]
__kmalloc_noprof+0x3d4/0x4b0 mm/slub.c:4388
kmalloc_noprof include/linux/slab.h:909 [inline]
kmalloc_array_noprof include/linux/slab.h:948 [inline]
xe_exec_ioctl+0xa47/0x1e70 drivers/gpu/drm/xe/xe_exec.c:158
drm_ioctl_kernel+0x1f1/0x3e0 drivers/gpu/drm/drm_ioctl.c:797
drm_ioctl+0x5e7/0xc50 drivers/gpu/drm/drm_ioctl.c:894
xe_drm_ioctl+0x10b/0x170 drivers/gpu/drm/xe/xe_device.c:224
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:598 [inline]
__se_sys_ioctl fs/ioctl.c:584 [inline]
__x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xbb/0x380 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
"
v2: Add "Reported-by" and Cc stable kernels.
v3: Change XE_MAX_SYNCS from 64 to 1024. (Matt & Ashutosh)
v4: s/XE_MAX_SYNCS/DRM_XE_MAX_SYNCS/ (Matt)
v5: Do the check at the top of the exec func. (Matt)
(cherry picked from commit b07bac9bd708ec468cd1b8a5fe70ae2ac9b0a11c) |
| In the Linux kernel, the following vulnerability has been resolved:
platform/chrome: cros_ec_ishtp: Fix UAF after unbinding driver
After unbinding the driver, another kthread `cros_ec_console_log_work`
is still accessing the device, resulting an UAF and crash.
The driver doesn't unregister the EC device in .remove() which should
shutdown sub-devices synchronously. Fix it. |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix race between wbt_enable_default and IO submission
When wbt_enable_default() is moved out of queue freezing in elevator_change(),
it can cause the wbt inflight counter to become negative (-1), leading to hung
tasks in the writeback path. Tasks get stuck in wbt_wait() because the counter
is in an inconsistent state.
The issue occurs because wbt_enable_default() could race with IO submission,
allowing the counter to be decremented before proper initialization. This manifests
as:
rq_wait[0]:
inflight: -1
has_waiters: True
rwb_enabled() checks the state, which can be updated exactly between wbt_wait()
(rq_qos_throttle()) and wbt_track()(rq_qos_track()), then the inflight counter
will become negative.
And results in hung task warnings like:
task:kworker/u24:39 state:D stack:0 pid:14767
Call Trace:
rq_qos_wait+0xb4/0x150
wbt_wait+0xa9/0x100
__rq_qos_throttle+0x24/0x40
blk_mq_submit_bio+0x672/0x7b0
...
Fix this by:
1. Splitting wbt_enable_default() into:
- __wbt_enable_default(): Returns true if wbt_init() should be called
- wbt_enable_default(): Wrapper for existing callers (no init)
- wbt_init_enable_default(): New function that checks and inits WBT
2. Using wbt_init_enable_default() in blk_register_queue() to ensure
proper initialization during queue registration
3. Move wbt_init() out of wbt_enable_default() which is only for enabling
disabled wbt from bfq and iocost, and wbt_init() isn't needed. Then the
original lock warning can be avoided.
4. Removing the ELEVATOR_FLAG_ENABLE_WBT_ON_EXIT flag and its handling
code since it's no longer needed
This ensures WBT is properly initialized before any IO can be submitted,
preventing the counter from going negative. |
| In the Linux kernel, the following vulnerability has been resolved:
fuse: fix readahead reclaim deadlock
Commit e26ee4efbc79 ("fuse: allocate ff->release_args only if release is
needed") skips allocating ff->release_args if the server does not
implement open. However in doing so, fuse_prepare_release() now skips
grabbing the reference on the inode, which makes it possible for an
inode to be evicted from the dcache while there are inflight readahead
requests. This causes a deadlock if the server triggers reclaim while
servicing the readahead request and reclaim attempts to evict the inode
of the file being read ahead. Since the folio is locked during
readahead, when reclaim evicts the fuse inode and fuse_evict_inode()
attempts to remove all folios associated with the inode from the page
cache (truncate_inode_pages_range()), reclaim will block forever waiting
for the lock since readahead cannot relinquish the lock because it is
itself blocked in reclaim:
>>> stack_trace(1504735)
folio_wait_bit_common (mm/filemap.c:1308:4)
folio_lock (./include/linux/pagemap.h:1052:3)
truncate_inode_pages_range (mm/truncate.c:336:10)
fuse_evict_inode (fs/fuse/inode.c:161:2)
evict (fs/inode.c:704:3)
dentry_unlink_inode (fs/dcache.c:412:3)
__dentry_kill (fs/dcache.c:615:3)
shrink_kill (fs/dcache.c:1060:12)
shrink_dentry_list (fs/dcache.c:1087:3)
prune_dcache_sb (fs/dcache.c:1168:2)
super_cache_scan (fs/super.c:221:10)
do_shrink_slab (mm/shrinker.c:435:9)
shrink_slab (mm/shrinker.c:626:10)
shrink_node (mm/vmscan.c:5951:2)
shrink_zones (mm/vmscan.c:6195:3)
do_try_to_free_pages (mm/vmscan.c:6257:3)
do_swap_page (mm/memory.c:4136:11)
handle_pte_fault (mm/memory.c:5562:10)
handle_mm_fault (mm/memory.c:5870:9)
do_user_addr_fault (arch/x86/mm/fault.c:1338:10)
handle_page_fault (arch/x86/mm/fault.c:1481:3)
exc_page_fault (arch/x86/mm/fault.c:1539:2)
asm_exc_page_fault+0x22/0x27
Fix this deadlock by allocating ff->release_args and grabbing the
reference on the inode when preparing the file for release even if the
server does not implement open. The inode reference will be dropped when
the last reference on the fuse file is dropped (see fuse_file_put() ->
fuse_release_end()). |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid potential deadlock
As Jiaming Zhang and syzbot reported, there is potential deadlock in
f2fs as below:
Chain exists of:
&sbi->cp_rwsem --> fs_reclaim --> sb_internal#2
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(sb_internal#2);
lock(fs_reclaim);
lock(sb_internal#2);
rlock(&sbi->cp_rwsem);
*** DEADLOCK ***
3 locks held by kswapd0/73:
#0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline]
#0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389
#1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline]
#1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197
#2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890
stack backtrace:
CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537
f2fs_down_read fs/f2fs/f2fs.h:2278 [inline]
f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline]
f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791
f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867
f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925
f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897
evict+0x504/0x9c0 fs/inode.c:810
f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853
evict+0x504/0x9c0 fs/inode.c:810
dispose_list fs/inode.c:852 [inline]
prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000
super_cache_scan+0x39b/0x4b0 fs/super.c:224
do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437
shrink_slab_memcg mm/shrinker.c:550 [inline]
shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628
shrink_one+0x28a/0x7c0 mm/vmscan.c:4955
shrink_many mm/vmscan.c:5016 [inline]
lru_gen_shrink_node mm/vmscan.c:5094 [inline]
shrink_node+0x315d/0x3780 mm/vmscan.c:6081
kswapd_shrink_node mm/vmscan.c:6941 [inline]
balance_pgdat mm/vmscan.c:7124 [inline]
kswapd+0x147c/0x2800 mm/vmscan.c:7389
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
The root cause is deadlock among four locks as below:
kswapd
- fs_reclaim --- Lock A
- shrink_one
- evict
- f2fs_evict_inode
- sb_start_intwrite --- Lock B
- iput
- evict
- f2fs_evict_inode
- sb_start_intwrite --- Lock B
- f2fs_truncate
- f2fs_truncate_blocks
- f2fs_do_truncate_blocks
- f2fs_lock_op --- Lock C
ioctl
- f2fs_ioc_commit_atomic_write
- f2fs_lock_op --- Lock C
- __f2fs_commit_atomic_write
- __replace_atomic_write_block
- f2fs_get_dnode_of_data
- __get_node_folio
- f2fs_check_nid_range
- f2fs_handle_error
- f2fs_record_errors
- f2fs_down_write --- Lock D
open
- do_open
- do_truncate
- security_inode_need_killpriv
- f2fs_getxattr
- lookup_all_xattrs
- f2fs_handle_error
- f2fs_record_errors
- f2fs_down_write --- Lock D
- f2fs_commit_super
- read_mapping_folio
- filemap_alloc_folio_noprof
- prepare_alloc_pages
- fs_reclaim_acquire --- Lock A
In order to a
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: set dummy blocksize to read boot_block when mounting
When mounting, sb->s_blocksize is used to read the boot_block without
being defined or validated. Set a dummy blocksize before attempting to
read the boot_block.
The issue can be triggered with the following syz reproducer:
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./file1\x00', 0x0)
r4 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x121403, 0x0)
ioctl$FS_IOC_SETFLAGS(r4, 0x40081271, &(0x7f0000000980)=0x4000)
mount(&(0x7f0000000140)=@nullb, &(0x7f0000000040)='./cgroup\x00',
&(0x7f0000000000)='ntfs3\x00', 0x2208004, 0x0)
syz_clone(0x88200200, 0x0, 0x0, 0x0, 0x0, 0x0)
Here, the ioctl sets the bdev block size to 16384. During mount,
get_tree_bdev_flags() calls sb_set_blocksize(sb, block_size(bdev)),
but since block_size(bdev) > PAGE_SIZE, sb_set_blocksize() leaves
sb->s_blocksize at zero.
Later, ntfs_init_from_boot() attempts to read the boot_block while
sb->s_blocksize is still zero, which triggers the bug.
[almaz.alexandrovich@paragon-software.com: changed comment style, added
return value handling] |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: invalidate dentry cache on failed whiteout creation
F2FS can mount filesystems with corrupted directory depth values that
get runtime-clamped to MAX_DIR_HASH_DEPTH. When RENAME_WHITEOUT
operations are performed on such directories, f2fs_rename performs
directory modifications (updating target entry and deleting source
entry) before attempting to add the whiteout entry via f2fs_add_link.
If f2fs_add_link fails due to the corrupted directory structure, the
function returns an error to VFS, but the partial directory
modifications have already been committed to disk. VFS assumes the
entire rename operation failed and does not update the dentry cache,
leaving stale mappings.
In the error path, VFS does not call d_move() to update the dentry
cache. This results in new_dentry still pointing to the old inode
(new_inode) which has already had its i_nlink decremented to zero.
The stale cache causes subsequent operations to incorrectly reference
the freed inode.
This causes subsequent operations to use cached dentry information that
no longer matches the on-disk state. When a second rename targets the
same entry, VFS attempts to decrement i_nlink on the stale inode, which
may already have i_nlink=0, triggering a WARNING in drop_nlink().
Example sequence:
1. First rename (RENAME_WHITEOUT): file2 → file1
- f2fs updates file1 entry on disk (points to inode 8)
- f2fs deletes file2 entry on disk
- f2fs_add_link(whiteout) fails (corrupted directory)
- Returns error to VFS
- VFS does not call d_move() due to error
- VFS cache still has: file1 → inode 7 (stale!)
- inode 7 has i_nlink=0 (already decremented)
2. Second rename: file3 → file1
- VFS uses stale cache: file1 → inode 7
- Tries to drop_nlink on inode 7 (i_nlink already 0)
- WARNING in drop_nlink()
Fix this by explicitly invalidating old_dentry and new_dentry when
f2fs_add_link fails during whiteout creation. This forces VFS to
refresh from disk on subsequent operations, ensuring cache consistency
even when the rename partially succeeds.
Reproducer:
1. Mount F2FS image with corrupted i_current_depth
2. renameat2(file2, file1, RENAME_WHITEOUT)
3. renameat2(file3, file1, 0)
4. System triggers WARNING in drop_nlink() |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Add preempt_count_{sub,add} into btf id deny list
The recursion check in __bpf_prog_enter* and __bpf_prog_exit*
leave preempt_count_{sub,add} unprotected. When attaching trampoline to
them we get panic as follows,
[ 867.843050] BUG: TASK stack guard page was hit at 0000000009d325cf (stack is 0000000046a46a15..00000000537e7b28)
[ 867.843064] stack guard page: 0000 [#1] PREEMPT SMP NOPTI
[ 867.843067] CPU: 8 PID: 11009 Comm: trace Kdump: loaded Not tainted 6.2.0+ #4
[ 867.843100] Call Trace:
[ 867.843101] <TASK>
[ 867.843104] asm_exc_int3+0x3a/0x40
[ 867.843108] RIP: 0010:preempt_count_sub+0x1/0xa0
[ 867.843135] __bpf_prog_enter_recur+0x17/0x90
[ 867.843148] bpf_trampoline_6442468108_0+0x2e/0x1000
[ 867.843154] ? preempt_count_sub+0x1/0xa0
[ 867.843157] preempt_count_sub+0x5/0xa0
[ 867.843159] ? migrate_enable+0xac/0xf0
[ 867.843164] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843168] bpf_trampoline_6442468108_0+0x55/0x1000
...
[ 867.843788] preempt_count_sub+0x5/0xa0
[ 867.843793] ? migrate_enable+0xac/0xf0
[ 867.843829] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843837] BUG: IRQ stack guard page was hit at 0000000099bd8228 (stack is 00000000b23e2bc4..000000006d95af35)
[ 867.843841] BUG: IRQ stack guard page was hit at 000000005ae07924 (stack is 00000000ffd69623..0000000014eb594c)
[ 867.843843] BUG: IRQ stack guard page was hit at 00000000028320f0 (stack is 00000000034b6438..0000000078d1bcec)
[ 867.843842] bpf_trampoline_6442468108_0+0x55/0x1000
...
That is because in __bpf_prog_exit_recur, the preempt_count_{sub,add} are
called after prog->active is decreased.
Fixing this by adding these two functions into btf ids deny list. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: storage: Fix memory leak in USB bulk transport
A kernel memory leak was identified by the 'ioctl_sg01' test from Linux
Test Project (LTP). The following bytes were mainly observed: 0x53425355.
When USB storage devices incorrectly skip the data phase with status data,
the code extracts/validates the CSW from the sg buffer, but fails to clear
it afterwards. This leaves status protocol data in srb's transfer buffer,
such as the US_BULK_CS_SIGN 'USBS' signature observed here. Thus, this can
lead to USB protocols leaks to user space through SCSI generic (/dev/sg*)
interfaces, such as the one seen here when the LTP test requested 512 KiB.
Fix the leak by zeroing the CSW data in srb's transfer buffer immediately
after the validation of devices that skip data phase.
Note: Differently from CVE-2018-1000204, which fixed a big leak by zero-
ing pages at allocation time, this leak occurs after allocation, when USB
protocol data is written to already-allocated sg pages. |
| In the Linux kernel, the following vulnerability has been resolved:
backlight: led-bl: Add devlink to supplier LEDs
LED Backlight is a consumer of one or multiple LED class devices, but
devlink is currently unable to create correct supplier-producer links when
the supplier is a class device. It creates instead a link where the
supplier is the parent of the expected device.
One consequence is that removal order is not correctly enforced.
Issues happen for example with the following sections in a device tree
overlay:
// An LED driver chip
pca9632@62 {
compatible = "nxp,pca9632";
reg = <0x62>;
// ...
addon_led_pwm: led-pwm@3 {
reg = <3>;
label = "addon:led:pwm";
};
};
backlight-addon {
compatible = "led-backlight";
leds = <&addon_led_pwm>;
brightness-levels = <255>;
default-brightness-level = <255>;
};
In this example, the devlink should be created between the backlight-addon
(consumer) and the pca9632@62 (supplier). Instead it is created between the
backlight-addon (consumer) and the parent of the pca9632@62, which is
typically the I2C bus adapter.
On removal of the above overlay, the LED driver can be removed before the
backlight device, resulting in:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
...
Call trace:
led_put+0xe0/0x140
devm_led_release+0x6c/0x98
Another way to reproduce the bug without any device tree overlays is
unbinding the LED class device (pca9632@62) before unbinding the consumer
(backlight-addon):
echo 11-0062 >/sys/bus/i2c/drivers/leds-pca963x/unbind
echo ...backlight-dock >/sys/bus/platform/drivers/led-backlight/unbind
Fix by adding a devlink between the consuming led-backlight device and the
supplying LED device, as other drivers and subsystems do as well. |
| In the Linux kernel, the following vulnerability has been resolved:
comedi: multiq3: sanitize config options in multiq3_attach()
Syzbot identified an issue [1] in multiq3_attach() that induces a
task timeout due to open() or COMEDI_DEVCONFIG ioctl operations,
specifically, in the case of multiq3 driver.
This problem arose when syzkaller managed to craft weird configuration
options used to specify the number of channels in encoder subdevice.
If a particularly great number is passed to s->n_chan in
multiq3_attach() via it->options[2], then multiple calls to
multiq3_encoder_reset() at the end of driver-specific attach() method
will be running for minutes, thus blocking tasks and affected devices
as well.
While this issue is most likely not too dangerous for real-life
devices, it still makes sense to sanitize configuration inputs. Enable
a sensible limit on the number of encoder chips (4 chips max, each
with 2 channels) to stop this behaviour from manifesting.
[1] Syzbot crash:
INFO: task syz.2.19:6067 blocked for more than 143 seconds.
...
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5254 [inline]
__schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
__schedule_loop kernel/sched/core.c:6944 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6959
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
do_dentry_open+0x953/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1097
... |
| In the Linux kernel, the following vulnerability has been resolved:
comedi: check device's attached status in compat ioctls
Syzbot identified an issue [1] that crashes kernel, seemingly due to
unexistent callback dev->get_valid_routes(). By all means, this should
not occur as said callback must always be set to
get_zero_valid_routes() in __comedi_device_postconfig().
As the crash seems to appear exclusively in i386 kernels, at least,
judging from [1] reports, the blame lies with compat versions
of standard IOCTL handlers. Several of them are modified and
do not use comedi_unlocked_ioctl(). While functionality of these
ioctls essentially copy their original versions, they do not
have required sanity check for device's attached status. This,
in turn, leads to a possibility of calling select IOCTLs on a
device that has not been properly setup, even via COMEDI_DEVCONFIG.
Doing so on unconfigured devices means that several crucial steps
are missed, for instance, specifying dev->get_valid_routes()
callback.
Fix this somewhat crudely by ensuring device's attached status before
performing any ioctls, improving logic consistency between modern
and compat functions.
[1] Syzbot report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
...
CR2: ffffffffffffffd6 CR3: 000000006c717000 CR4: 0000000000352ef0
Call Trace:
<TASK>
get_valid_routes drivers/comedi/comedi_fops.c:1322 [inline]
parse_insn+0x78c/0x1970 drivers/comedi/comedi_fops.c:1401
do_insnlist_ioctl+0x272/0x700 drivers/comedi/comedi_fops.c:1594
compat_insnlist drivers/comedi/comedi_fops.c:3208 [inline]
comedi_compat_ioctl+0x810/0x990 drivers/comedi/comedi_fops.c:3273
__do_compat_sys_ioctl fs/ioctl.c:695 [inline]
__se_compat_sys_ioctl fs/ioctl.c:638 [inline]
__ia32_compat_sys_ioctl+0x242/0x370 fs/ioctl.c:638
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
... |
| In the Linux kernel, the following vulnerability has been resolved:
comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel()
Syzbot identified an issue [1] in pcl818_ai_cancel(), which stems from
the fact that in case of early device detach via pcl818_detach(),
subdevice dev->read_subdev may not have initialized its pointer to
&struct comedi_async as intended. Thus, any such dereferencing of
&s->async->cmd will lead to general protection fault and kernel crash.
Mitigate this problem by removing a call to pcl818_ai_cancel() from
pcl818_detach() altogether. This way, if the subdevice setups its
support for async commands, everything async-related will be
handled via subdevice's own ->cancel() function in
comedi_device_detach_locked() even before pcl818_detach(). If no
support for asynchronous commands is provided, there is no need
to cancel anything either.
[1] Syzbot crash:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 1 UID: 0 PID: 6050 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pcl818_ai_cancel+0x69/0x3f0 drivers/comedi/drivers/pcl818.c:762
...
Call Trace:
<TASK>
pcl818_detach+0x66/0xd0 drivers/comedi/drivers/pcl818.c:1115
comedi_device_detach_locked+0x178/0x750 drivers/comedi/drivers.c:207
do_devconfig_ioctl drivers/comedi/comedi_fops.c:848 [inline]
comedi_unlocked_ioctl+0xcde/0x1020 drivers/comedi/comedi_fops.c:2178
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
... |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log
It's trivial for user to trigger "verifier log line truncated" warning,
as verifier has a fixed-sized buffer of 1024 bytes (as of now), and there are at
least two pieces of user-provided information that can be output through
this buffer, and both can be arbitrarily sized by user:
- BTF names;
- BTF.ext source code lines strings.
Verifier log buffer should be properly sized for typical verifier state
output. But it's sort-of expected that this buffer won't be long enough
in some circumstances. So let's drop the check. In any case code will
work correctly, at worst truncating a part of a single line output. |
| In the Linux kernel, the following vulnerability has been resolved:
blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx
In __blk_mq_update_nr_hw_queues() the return value of
blk_mq_sysfs_register_hctxs() is not checked. If sysfs creation for hctx
fails, later changing the number of hw_queues or removing disk will
trigger the following warning:
kernfs: can not remove 'nr_tags', no directory
WARNING: CPU: 2 PID: 637 at fs/kernfs/dir.c:1707 kernfs_remove_by_name_ns+0x13f/0x160
Call Trace:
remove_files.isra.1+0x38/0xb0
sysfs_remove_group+0x4d/0x100
sysfs_remove_groups+0x31/0x60
__kobject_del+0x23/0xf0
kobject_del+0x17/0x40
blk_mq_unregister_hctx+0x5d/0x80
blk_mq_sysfs_unregister_hctxs+0x94/0xd0
blk_mq_update_nr_hw_queues+0x124/0x760
nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]
nullb_device_submit_queues_store+0x92/0x120 [null_blk]
kobjct_del() was called unconditionally even if sysfs creation failed.
Fix it by checkig the kobject creation statusbefore deleting it. |
| In the Linux kernel, the following vulnerability has been resolved:
posix-timers: Ensure timer ID search-loop limit is valid
posix_timer_add() tries to allocate a posix timer ID by starting from the
cached ID which was stored by the last successful allocation.
This is done in a loop searching the ID space for a free slot one by
one. The loop has to terminate when the search wrapped around to the
starting point.
But that's racy vs. establishing the starting point. That is read out
lockless, which leads to the following problem:
CPU0 CPU1
posix_timer_add()
start = sig->posix_timer_id;
lock(hash_lock);
... posix_timer_add()
if (++sig->posix_timer_id < 0)
start = sig->posix_timer_id;
sig->posix_timer_id = 0;
So CPU1 can observe a negative start value, i.e. -1, and the loop break
never happens because the condition can never be true:
if (sig->posix_timer_id == start)
break;
While this is unlikely to ever turn into an endless loop as the ID space is
huge (INT_MAX), the racy read of the start value caught the attention of
KCSAN and Dmitry unearthed that incorrectness.
Rewrite it so that all id operations are under the hash lock. |
| In the Linux kernel, the following vulnerability has been resolved:
iavf: use internal state to free traffic IRQs
If the system tries to close the netdev while iavf_reset_task() is
running, __LINK_STATE_START will be cleared and netif_running() will
return false in iavf_reinit_interrupt_scheme(). This will result in
iavf_free_traffic_irqs() not being called and a leak as follows:
[7632.489326] remove_proc_entry: removing non-empty directory 'irq/999', leaking at least 'iavf-enp24s0f0v0-TxRx-0'
[7632.490214] WARNING: CPU: 0 PID: 10 at fs/proc/generic.c:718 remove_proc_entry+0x19b/0x1b0
is shown when pci_disable_msix() is later called. Fix by using the
internal adapter state. The traffic IRQs will always exist if
state == __IAVF_RUNNING. |
