| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: ac97: fix a double free in snd_ac97_controller_register()
If ac97_add_adapter() fails, put_device() is the correct way to drop
the device reference. kfree() is not required.
Add kfree() if idr_alloc() fails and in ac97_adapter_release() to do
the cleanup.
Found by code review. |
| In the Linux kernel, the following vulnerability has been resolved:
ublk: clean up user copy references on ublk server exit
If a ublk server process releases a ublk char device file, any requests
dispatched to the ublk server but not yet completed will retain a ref
value of UBLK_REFCOUNT_INIT. Before commit e63d2228ef83 ("ublk: simplify
aborting ublk request"), __ublk_fail_req() would decrement the reference
count before completing the failed request. However, that commit
optimized __ublk_fail_req() to call __ublk_complete_rq() directly
without decrementing the request reference count.
The leaked reference count incorrectly allows user copy and zero copy
operations on the completed ublk request. It also triggers the
WARN_ON_ONCE(refcount_read(&io->ref)) warnings in ublk_queue_reinit()
and ublk_deinit_queue().
Commit c5c5eb24ed61 ("ublk: avoid ublk_io_release() called after ublk
char dev is closed") already fixed the issue for ublk devices using
UBLK_F_SUPPORT_ZERO_COPY or UBLK_F_AUTO_BUF_REG. However, the reference
count leak also affects UBLK_F_USER_COPY, the other reference-counted
data copy mode. Fix the condition in ublk_check_and_reset_active_ref()
to include all reference-counted data copy modes. This ensures that any
ublk requests still owned by the ublk server when it exits have their
reference counts reset to 0. |
| 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:
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: 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:
media: tuner: xc5000: Fix use-after-free in xc5000_release
The original code uses cancel_delayed_work() in xc5000_release(), which
does not guarantee that the delayed work item timer_sleep has fully
completed if it was already running. This leads to use-after-free scenarios
where xc5000_release() may free the xc5000_priv while timer_sleep is still
active and attempts to dereference the xc5000_priv.
A typical race condition is illustrated below:
CPU 0 (release thread) | CPU 1 (delayed work callback)
xc5000_release() | xc5000_do_timer_sleep()
cancel_delayed_work() |
hybrid_tuner_release_state(priv) |
kfree(priv) |
| priv = container_of() // UAF
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the timer_sleep is properly canceled before the xc5000_priv memory
is deallocated.
A deadlock concern was considered: xc5000_release() is called in a process
context and is not holding any locks that the timer_sleep work item might
also need. Therefore, the use of the _sync() variant is safe here.
This bug was initially identified through static analysis.
[hverkuil: fix typo in Subject: tunner -> tuner] |
| In the Linux kernel, the following vulnerability has been resolved:
media: i2c: tc358743: Fix use-after-free bugs caused by orphan timer in probe
The state->timer is a cyclic timer that schedules work_i2c_poll and
delayed_work_enable_hotplug, while rearming itself. Using timer_delete()
fails to guarantee the timer isn't still running when destroyed, similarly
cancel_delayed_work() cannot ensure delayed_work_enable_hotplug has
terminated if already executing. During probe failure after timer
initialization, these may continue running as orphans and reference the
already-freed tc358743_state object through tc358743_irq_poll_timer.
The following is the trace captured by KASAN.
BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0
Write of size 8 at addr ffff88800ded83c8 by task swapper/1/0
...
Call Trace:
<IRQ>
dump_stack_lvl+0x55/0x70
print_report+0xcf/0x610
? __pfx_sched_balance_find_src_group+0x10/0x10
? __run_timer_base.part.0+0x7d7/0x8c0
kasan_report+0xb8/0xf0
? __run_timer_base.part.0+0x7d7/0x8c0
__run_timer_base.part.0+0x7d7/0x8c0
? rcu_sched_clock_irq+0xb06/0x27d0
? __pfx___run_timer_base.part.0+0x10/0x10
? try_to_wake_up+0xb15/0x1960
? tmigr_update_events+0x280/0x740
? _raw_spin_lock_irq+0x80/0xe0
? __pfx__raw_spin_lock_irq+0x10/0x10
tmigr_handle_remote_up+0x603/0x7e0
? __pfx_tmigr_handle_remote_up+0x10/0x10
? sched_balance_trigger+0x98/0x9f0
? sched_tick+0x221/0x5a0
? _raw_spin_lock_irq+0x80/0xe0
? __pfx__raw_spin_lock_irq+0x10/0x10
? tick_nohz_handler+0x339/0x440
? __pfx_tmigr_handle_remote_up+0x10/0x10
__walk_groups.isra.0+0x42/0x150
tmigr_handle_remote+0x1f4/0x2e0
? __pfx_tmigr_handle_remote+0x10/0x10
? ktime_get+0x60/0x140
? lapic_next_event+0x11/0x20
? clockevents_program_event+0x1d4/0x2a0
? hrtimer_interrupt+0x322/0x780
handle_softirqs+0x16a/0x550
irq_exit_rcu+0xaf/0xe0
sysvec_apic_timer_interrupt+0x70/0x80
</IRQ>
...
Allocated by task 141:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x7f/0x90
__kmalloc_node_track_caller_noprof+0x198/0x430
devm_kmalloc+0x7b/0x1e0
tc358743_probe+0xb7/0x610 i2c_device_probe+0x51d/0x880
really_probe+0x1ca/0x5c0
__driver_probe_device+0x248/0x310
driver_probe_device+0x44/0x120
__device_attach_driver+0x174/0x220
bus_for_each_drv+0x100/0x190
__device_attach+0x206/0x370
bus_probe_device+0x123/0x170
device_add+0xd25/0x1470
i2c_new_client_device+0x7a0/0xcd0
do_one_initcall+0x89/0x300
do_init_module+0x29d/0x7f0
load_module+0x4f48/0x69e0
init_module_from_file+0xe4/0x150
idempotent_init_module+0x320/0x670
__x64_sys_finit_module+0xbd/0x120
do_syscall_64+0xac/0x280
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 141:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3a/0x60
__kasan_slab_free+0x3f/0x50
kfree+0x137/0x370
release_nodes+0xa4/0x100
devres_release_group+0x1b2/0x380
i2c_device_probe+0x694/0x880
really_probe+0x1ca/0x5c0
__driver_probe_device+0x248/0x310
driver_probe_device+0x44/0x120
__device_attach_driver+0x174/0x220
bus_for_each_drv+0x100/0x190
__device_attach+0x206/0x370
bus_probe_device+0x123/0x170
device_add+0xd25/0x1470
i2c_new_client_device+0x7a0/0xcd0
do_one_initcall+0x89/0x300
do_init_module+0x29d/0x7f0
load_module+0x4f48/0x69e0
init_module_from_file+0xe4/0x150
idempotent_init_module+0x320/0x670
__x64_sys_finit_module+0xbd/0x120
do_syscall_64+0xac/0x280
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
Replace timer_delete() with timer_delete_sync() and cancel_delayed_work()
with cancel_delayed_work_sync() to ensure proper termination of timer and
work items before resource cleanup.
This bug was initially identified through static analysis. For reproduction
and testing, I created a functional emulation of the tc358743 device via a
kernel module and introduced faults through the debugfs interface. |
| In the Linux kernel, the following vulnerability has been resolved:
media: b2c2: Fix use-after-free causing by irq_check_work in flexcop_pci_remove
The original code uses cancel_delayed_work() in flexcop_pci_remove(), which
does not guarantee that the delayed work item irq_check_work has fully
completed if it was already running. This leads to use-after-free scenarios
where flexcop_pci_remove() may free the flexcop_device while irq_check_work
is still active and attempts to dereference the device.
A typical race condition is illustrated below:
CPU 0 (remove) | CPU 1 (delayed work callback)
flexcop_pci_remove() | flexcop_pci_irq_check_work()
cancel_delayed_work() |
flexcop_device_kfree(fc_pci->fc_dev) |
| fc = fc_pci->fc_dev; // UAF
This is confirmed by a KASAN report:
==================================================================
BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0
Write of size 8 at addr ffff8880093aa8c8 by task bash/135
...
Call Trace:
<IRQ>
dump_stack_lvl+0x55/0x70
print_report+0xcf/0x610
? __run_timer_base.part.0+0x7d7/0x8c0
kasan_report+0xb8/0xf0
? __run_timer_base.part.0+0x7d7/0x8c0
__run_timer_base.part.0+0x7d7/0x8c0
? __pfx___run_timer_base.part.0+0x10/0x10
? __pfx_read_tsc+0x10/0x10
? ktime_get+0x60/0x140
? lapic_next_event+0x11/0x20
? clockevents_program_event+0x1d4/0x2a0
run_timer_softirq+0xd1/0x190
handle_softirqs+0x16a/0x550
irq_exit_rcu+0xaf/0xe0
sysvec_apic_timer_interrupt+0x70/0x80
</IRQ>
...
Allocated by task 1:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x7f/0x90
__kmalloc_noprof+0x1be/0x460
flexcop_device_kmalloc+0x54/0xe0
flexcop_pci_probe+0x1f/0x9d0
local_pci_probe+0xdc/0x190
pci_device_probe+0x2fe/0x470
really_probe+0x1ca/0x5c0
__driver_probe_device+0x248/0x310
driver_probe_device+0x44/0x120
__driver_attach+0xd2/0x310
bus_for_each_dev+0xed/0x170
bus_add_driver+0x208/0x500
driver_register+0x132/0x460
do_one_initcall+0x89/0x300
kernel_init_freeable+0x40d/0x720
kernel_init+0x1a/0x150
ret_from_fork+0x10c/0x1a0
ret_from_fork_asm+0x1a/0x30
Freed by task 135:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3a/0x60
__kasan_slab_free+0x3f/0x50
kfree+0x137/0x370
flexcop_device_kfree+0x32/0x50
pci_device_remove+0xa6/0x1d0
device_release_driver_internal+0xf8/0x210
pci_stop_bus_device+0x105/0x150
pci_stop_and_remove_bus_device_locked+0x15/0x30
remove_store+0xcc/0xe0
kernfs_fop_write_iter+0x2c3/0x440
vfs_write+0x871/0xd70
ksys_write+0xee/0x1c0
do_syscall_64+0xac/0x280
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the delayed work item is properly canceled and any executing delayed
work has finished before the device memory is deallocated.
This bug was initially identified through static analysis. To reproduce
and test it, I simulated the B2C2 FlexCop PCI device in QEMU and introduced
artificial delays within the flexcop_pci_irq_check_work() function to
increase the likelihood of triggering the bug. |
| In the Linux kernel, the following vulnerability has been resolved:
blk-mq: fix blk_mq_tags double free while nr_requests grown
In the case user trigger tags grow by queue sysfs attribute nr_requests,
hctx->sched_tags will be freed directly and replaced with a new
allocated tags, see blk_mq_tag_update_depth().
The problem is that hctx->sched_tags is from elevator->et->tags, while
et->tags is still the freed tags, hence later elevator exit will try to
free the tags again, causing kernel panic.
Fix this problem by replacing et->tags with new allocated tags as well.
Noted there are still some long term problems that will require some
refactor to be fixed thoroughly[1].
[1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/ |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: mvsas: Fix use-after-free bugs in mvs_work_queue
During the detaching of Marvell's SAS/SATA controller, the original code
calls cancel_delayed_work() in mvs_free() to cancel the delayed work
item mwq->work_q. However, if mwq->work_q is already running, the
cancel_delayed_work() may fail to cancel it. This can lead to
use-after-free scenarios where mvs_free() frees the mvs_info while
mvs_work_queue() is still executing and attempts to access the
already-freed mvs_info.
A typical race condition is illustrated below:
CPU 0 (remove) | CPU 1 (delayed work callback)
mvs_pci_remove() |
mvs_free() | mvs_work_queue()
cancel_delayed_work() |
kfree(mvi) |
| mvi-> // UAF
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the delayed work item is properly canceled and any executing
delayed work item completes before the mvs_info is deallocated.
This bug was found by static analysis. |
| In the Linux kernel, the following vulnerability has been resolved:
net: mscc: ocelot: Fix use-after-free caused by cyclic delayed work
The origin code calls cancel_delayed_work() in ocelot_stats_deinit()
to cancel the cyclic delayed work item ocelot->stats_work. However,
cancel_delayed_work() may fail to cancel the work item if it is already
executing. While destroy_workqueue() does wait for all pending work items
in the work queue to complete before destroying the work queue, it cannot
prevent the delayed work item from being rescheduled within the
ocelot_check_stats_work() function. This limitation exists because the
delayed work item is only enqueued into the work queue after its timer
expires. Before the timer expiration, destroy_workqueue() has no visibility
of this pending work item. Once the work queue appears empty,
destroy_workqueue() proceeds with destruction. When the timer eventually
expires, the delayed work item gets queued again, leading to the following
warning:
workqueue: cannot queue ocelot_check_stats_work on wq ocelot-switch-stats
WARNING: CPU: 2 PID: 0 at kernel/workqueue.c:2255 __queue_work+0x875/0xaf0
...
RIP: 0010:__queue_work+0x875/0xaf0
...
RSP: 0018:ffff88806d108b10 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000101 RCX: 0000000000000027
RDX: 0000000000000027 RSI: 0000000000000004 RDI: ffff88806d123e88
RBP: ffffffff813c3170 R08: 0000000000000000 R09: ffffed100da247d2
R10: ffffed100da247d1 R11: ffff88806d123e8b R12: ffff88800c00f000
R13: ffff88800d7285c0 R14: ffff88806d0a5580 R15: ffff88800d7285a0
FS: 0000000000000000(0000) GS:ffff8880e5725000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe18e45ea10 CR3: 0000000005e6c000 CR4: 00000000000006f0
Call Trace:
<IRQ>
? kasan_report+0xc6/0xf0
? __pfx_delayed_work_timer_fn+0x10/0x10
? __pfx_delayed_work_timer_fn+0x10/0x10
call_timer_fn+0x25/0x1c0
__run_timer_base.part.0+0x3be/0x8c0
? __pfx_delayed_work_timer_fn+0x10/0x10
? rcu_sched_clock_irq+0xb06/0x27d0
? __pfx___run_timer_base.part.0+0x10/0x10
? try_to_wake_up+0xb15/0x1960
? _raw_spin_lock_irq+0x80/0xe0
? __pfx__raw_spin_lock_irq+0x10/0x10
tmigr_handle_remote_up+0x603/0x7e0
? __pfx_tmigr_handle_remote_up+0x10/0x10
? sched_balance_trigger+0x1c0/0x9f0
? sched_tick+0x221/0x5a0
? _raw_spin_lock_irq+0x80/0xe0
? __pfx__raw_spin_lock_irq+0x10/0x10
? tick_nohz_handler+0x339/0x440
? __pfx_tmigr_handle_remote_up+0x10/0x10
__walk_groups.isra.0+0x42/0x150
tmigr_handle_remote+0x1f4/0x2e0
? __pfx_tmigr_handle_remote+0x10/0x10
? ktime_get+0x60/0x140
? lapic_next_event+0x11/0x20
? clockevents_program_event+0x1d4/0x2a0
? hrtimer_interrupt+0x322/0x780
handle_softirqs+0x16a/0x550
irq_exit_rcu+0xaf/0xe0
sysvec_apic_timer_interrupt+0x70/0x80
</IRQ>
...
The following diagram reveals the cause of the above warning:
CPU 0 (remove) | CPU 1 (delayed work callback)
mscc_ocelot_remove() |
ocelot_deinit() | ocelot_check_stats_work()
ocelot_stats_deinit() |
cancel_delayed_work()| ...
| queue_delayed_work()
destroy_workqueue() | (wait a time)
| __queue_work() //UAF
The above scenario actually constitutes a UAF vulnerability.
The ocelot_stats_deinit() is only invoked when initialization
failure or resource destruction, so we must ensure that any
delayed work items cannot be rescheduled.
Replace cancel_delayed_work() with disable_delayed_work_sync()
to guarantee proper cancellation of the delayed work item and
ensure completion of any currently executing work before the
workqueue is deallocated.
A deadlock concern was considered: ocelot_stats_deinit() is called
in a process context and is not holding any locks that the delayed
work item might also need. Therefore, the use of the _sync() variant
is safe here.
This bug was identified through static analysis. To reproduce the
issue and validate the fix, I simulated ocelot-swit
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
Input: alps - fix use-after-free bugs caused by dev3_register_work
The dev3_register_work delayed work item is initialized within
alps_reconnect() and scheduled upon receipt of the first bare
PS/2 packet from an external PS/2 device connected to the ALPS
touchpad. During device detachment, the original implementation
calls flush_workqueue() in psmouse_disconnect() to ensure
completion of dev3_register_work. However, the flush_workqueue()
in psmouse_disconnect() only blocks and waits for work items that
were already queued to the workqueue prior to its invocation. Any
work items submitted after flush_workqueue() is called are not
included in the set of tasks that the flush operation awaits.
This means that after flush_workqueue() has finished executing,
the dev3_register_work could still be scheduled. Although the
psmouse state is set to PSMOUSE_CMD_MODE in psmouse_disconnect(),
the scheduling of dev3_register_work remains unaffected.
The race condition can occur as follows:
CPU 0 (cleanup path) | CPU 1 (delayed work)
psmouse_disconnect() |
psmouse_set_state() |
flush_workqueue() | alps_report_bare_ps2_packet()
alps_disconnect() | psmouse_queue_work()
kfree(priv); // FREE | alps_register_bare_ps2_mouse()
| priv = container_of(work...); // USE
| priv->dev3 // USE
Add disable_delayed_work_sync() in alps_disconnect() to ensure
that dev3_register_work is properly canceled and prevented from
executing after the alps_data structure has been deallocated.
This bug is identified by static analysis. |
| In the Linux kernel, the following vulnerability has been resolved:
net/9p: Fix buffer overflow in USB transport layer
A buffer overflow vulnerability exists in the USB 9pfs transport layer
where inconsistent size validation between packet header parsing and
actual data copying allows a malicious USB host to overflow heap buffers.
The issue occurs because:
- usb9pfs_rx_header() validates only the declared size in packet header
- usb9pfs_rx_complete() uses req->actual (actual received bytes) for
memcpy
This allows an attacker to craft packets with small declared size
(bypassing validation) but large actual payload (triggering overflow
in memcpy).
Add validation in usb9pfs_rx_complete() to ensure req->actual does not
exceed the buffer capacity before copying data. |
| 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:
scsi: Revert "scsi: qla2xxx: Perform lockless command completion in abort path"
This reverts commit 0367076b0817d5c75dfb83001ce7ce5c64d803a9.
The commit being reverted added code to __qla2x00_abort_all_cmds() to
call sp->done() without holding a spinlock. But unlike the older code
below it, this new code failed to check sp->cmd_type and just assumed
TYPE_SRB, which results in a jump to an invalid pointer in target-mode
with TYPE_TGT_CMD:
qla2xxx [0000:65:00.0]-d034:8: qla24xx_do_nack_work create sess success
0000000009f7a79b
qla2xxx [0000:65:00.0]-5003:8: ISP System Error - mbx1=1ff5h mbx2=10h
mbx3=0h mbx4=0h mbx5=191h mbx6=0h mbx7=0h.
qla2xxx [0000:65:00.0]-d01e:8: -> fwdump no buffer
qla2xxx [0000:65:00.0]-f03a:8: qla_target(0): System error async event
0x8002 occurred
qla2xxx [0000:65:00.0]-00af:8: Performing ISP error recovery -
ha=0000000058183fda.
BUG: kernel NULL pointer dereference, address: 0000000000000000
PF: supervisor instruction fetch in kernel mode
PF: error_code(0x0010) - not-present page
PGD 0 P4D 0
Oops: 0010 [#1] SMP
CPU: 2 PID: 9446 Comm: qla2xxx_8_dpc Tainted: G O 6.1.133 #1
Hardware name: Supermicro Super Server/X11SPL-F, BIOS 4.2 12/15/2023
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90001f93dc8 EFLAGS: 00010206
RAX: 0000000000000282 RBX: 0000000000000355 RCX: ffff88810d16a000
RDX: ffff88810dbadaa8 RSI: 0000000000080000 RDI: ffff888169dc38c0
RBP: ffff888169dc38c0 R08: 0000000000000001 R09: 0000000000000045
R10: ffffffffa034bdf0 R11: 0000000000000000 R12: ffff88810800bb40
R13: 0000000000001aa8 R14: ffff888100136610 R15: ffff8881070f7400
FS: 0000000000000000(0000) GS:ffff88bf80080000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000010c8ff006 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
? __die+0x4d/0x8b
? page_fault_oops+0x91/0x180
? trace_buffer_unlock_commit_regs+0x38/0x1a0
? exc_page_fault+0x391/0x5e0
? asm_exc_page_fault+0x22/0x30
__qla2x00_abort_all_cmds+0xcb/0x3e0 [qla2xxx_scst]
qla2x00_abort_all_cmds+0x50/0x70 [qla2xxx_scst]
qla2x00_abort_isp_cleanup+0x3b7/0x4b0 [qla2xxx_scst]
qla2x00_abort_isp+0xfd/0x860 [qla2xxx_scst]
qla2x00_do_dpc+0x581/0xa40 [qla2xxx_scst]
kthread+0xa8/0xd0
</TASK>
Then commit 4475afa2646d ("scsi: qla2xxx: Complete command early within
lock") added the spinlock back, because not having the lock caused a
race and a crash. But qla2x00_abort_srb() in the switch below already
checks for qla2x00_chip_is_down() and handles it the same way, so the
code above the switch is now redundant and still buggy in target-mode.
Remove it. |
| In the Linux kernel, the following vulnerability has been resolved:
media: dvb-usb: dtv5100: fix out-of-bounds in dtv5100_i2c_msg()
rlen value is a user-controlled value, but dtv5100_i2c_msg() does not
check the size of the rlen value. Therefore, if it is set to a value
larger than sizeof(st->data), an out-of-bounds vuln occurs for st->data.
Therefore, we need to add proper range checking to prevent this vuln. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: ets: Remove drr class from the active list if it changes to strict
Whenever a user issues an ets qdisc change command, transforming a
drr class into a strict one, the ets code isn't checking whether that
class was in the active list and removing it. This means that, if a
user changes a strict class (which was in the active list) back to a drr
one, that class will be added twice to the active list [1].
Doing so with the following commands:
tc qdisc add dev lo root handle 1: ets bands 2 strict 1
tc qdisc add dev lo parent 1:2 handle 20: \
tbf rate 8bit burst 100b latency 1s
tc filter add dev lo parent 1: basic classid 1:2
ping -c1 -W0.01 -s 56 127.0.0.1
tc qdisc change dev lo root handle 1: ets bands 2 strict 2
tc qdisc change dev lo root handle 1: ets bands 2 strict 1
ping -c1 -W0.01 -s 56 127.0.0.1
Will trigger the following splat with list debug turned on:
[ 59.279014][ T365] ------------[ cut here ]------------
[ 59.279452][ T365] list_add double add: new=ffff88801d60e350, prev=ffff88801d60e350, next=ffff88801d60e2c0.
[ 59.280153][ T365] WARNING: CPU: 3 PID: 365 at lib/list_debug.c:35 __list_add_valid_or_report+0x17f/0x220
[ 59.280860][ T365] Modules linked in:
[ 59.281165][ T365] CPU: 3 UID: 0 PID: 365 Comm: tc Not tainted 6.18.0-rc7-00105-g7e9f13163c13-dirty #239 PREEMPT(voluntary)
[ 59.281977][ T365] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 59.282391][ T365] RIP: 0010:__list_add_valid_or_report+0x17f/0x220
[ 59.282842][ T365] Code: 89 c6 e8 d4 b7 0d ff 90 0f 0b 90 90 31 c0 e9 31 ff ff ff 90 48 c7 c7 e0 a0 22 9f 48 89 f2 48 89 c1 4c 89 c6 e8 b2 b7 0d ff 90 <0f> 0b 90 90 31 c0 e9 0f ff ff ff 48 89 f7 48 89 44 24 10 4c 89 44
...
[ 59.288812][ T365] Call Trace:
[ 59.289056][ T365] <TASK>
[ 59.289224][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.289546][ T365] ets_qdisc_change+0xd2b/0x1e80
[ 59.289891][ T365] ? __lock_acquire+0x7e7/0x1be0
[ 59.290223][ T365] ? __pfx_ets_qdisc_change+0x10/0x10
[ 59.290546][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.290898][ T365] ? __mutex_trylock_common+0xda/0x240
[ 59.291228][ T365] ? __pfx___mutex_trylock_common+0x10/0x10
[ 59.291655][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.291993][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.292313][ T365] ? trace_contention_end+0xc8/0x110
[ 59.292656][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.293022][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.293351][ T365] tc_modify_qdisc+0x63a/0x1cf0
Fix this by always checking and removing an ets class from the active list
when changing it to strict.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/tree/net/sched/sch_ets.c?id=ce052b9402e461a9aded599f5b47e76bc727f7de#n663 |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot
Reject attempts to disable KVM_MEM_GUEST_MEMFD on a memslot that was
initially created with a guest_memfd binding, as KVM doesn't support
toggling KVM_MEM_GUEST_MEMFD on existing memslots. KVM prevents enabling
KVM_MEM_GUEST_MEMFD, but doesn't prevent clearing the flag.
Failure to reject the new memslot results in a use-after-free due to KVM
not unbinding from the guest_memfd instance. Unbinding on a FLAGS_ONLY
change is easy enough, and can/will be done as a hardening measure (in
anticipation of KVM supporting dirty logging on guest_memfd at some point),
but fixing the use-after-free would only address the immediate symptom.
==================================================================
BUG: KASAN: slab-use-after-free in kvm_gmem_release+0x362/0x400 [kvm]
Write of size 8 at addr ffff8881111ae908 by task repro/745
CPU: 7 UID: 1000 PID: 745 Comm: repro Not tainted 6.18.0-rc6-115d5de2eef3-next-kasan #3 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x51/0x60
print_report+0xcb/0x5c0
kasan_report+0xb4/0xe0
kvm_gmem_release+0x362/0x400 [kvm]
__fput+0x2fa/0x9d0
task_work_run+0x12c/0x200
do_exit+0x6ae/0x2100
do_group_exit+0xa8/0x230
__x64_sys_exit_group+0x3a/0x50
x64_sys_call+0x737/0x740
do_syscall_64+0x5b/0x900
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f581f2eac31
</TASK>
Allocated by task 745 on cpu 6 at 9.746971s:
kasan_save_stack+0x20/0x40
kasan_save_track+0x13/0x50
__kasan_kmalloc+0x77/0x90
kvm_set_memory_region.part.0+0x652/0x1110 [kvm]
kvm_vm_ioctl+0x14b0/0x3290 [kvm]
__x64_sys_ioctl+0x129/0x1a0
do_syscall_64+0x5b/0x900
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Freed by task 745 on cpu 6 at 9.747467s:
kasan_save_stack+0x20/0x40
kasan_save_track+0x13/0x50
__kasan_save_free_info+0x37/0x50
__kasan_slab_free+0x3b/0x60
kfree+0xf5/0x440
kvm_set_memslot+0x3c2/0x1160 [kvm]
kvm_set_memory_region.part.0+0x86a/0x1110 [kvm]
kvm_vm_ioctl+0x14b0/0x3290 [kvm]
__x64_sys_ioctl+0x129/0x1a0
do_syscall_64+0x5b/0x900
entry_SYSCALL_64_after_hwframe+0x4b/0x53 |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: vfs: fix race on m_flags in vfs_cache
ksmbd maintains delete-on-close and pending-delete state in
ksmbd_inode->m_flags. In vfs_cache.c this field is accessed under
inconsistent locking: some paths read and modify m_flags under
ci->m_lock while others do so without taking the lock at all.
Examples:
- ksmbd_query_inode_status() and __ksmbd_inode_close() use
ci->m_lock when checking or updating m_flags.
- ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(),
ksmbd_clear_inode_pending_delete() and ksmbd_fd_set_delete_on_close()
used to read and modify m_flags without ci->m_lock.
This creates a potential data race on m_flags when multiple threads
open, close and delete the same file concurrently. In the worst case
delete-on-close and pending-delete bits can be lost or observed in an
inconsistent state, leading to confusing delete semantics (files that
stay on disk after delete-on-close, or files that disappear while still
in use).
Fix it by:
- Making ksmbd_query_inode_status() look at m_flags under ci->m_lock
after dropping inode_hash_lock.
- Adding ci->m_lock protection to all helpers that read or modify
m_flags (ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(),
ksmbd_clear_inode_pending_delete(), ksmbd_fd_set_delete_on_close()).
- Keeping the existing ci->m_lock protection in __ksmbd_inode_close(),
and moving the actual unlink/xattr removal outside the lock.
This unifies the locking around m_flags and removes the data race while
preserving the existing delete-on-close behaviour. |
| In the Linux kernel, the following vulnerability has been resolved:
media: vidtv: initialize local pointers upon transfer of memory ownership
vidtv_channel_si_init() creates a temporary list (program, service, event)
and ownership of the memory itself is transferred to the PAT/SDT/EIT
tables through vidtv_psi_pat_program_assign(),
vidtv_psi_sdt_service_assign(), vidtv_psi_eit_event_assign().
The problem here is that the local pointer where the memory ownership
transfer was completed is not initialized to NULL. This causes the
vidtv_psi_pmt_create_sec_for_each_pat_entry() function to fail, and
in the flow that jumps to free_eit, the memory that was freed by
vidtv_psi_*_table_destroy() can be accessed again by
vidtv_psi_*_event_destroy() due to the uninitialized local pointer, so it
is freed once again.
Therefore, to prevent use-after-free and double-free vulnerability,
local pointers must be initialized to NULL when transferring memory
ownership. |
