Описание
In the Linux kernel, the following vulnerability has been resolved:
afs: Fix reinitialisation of the inode, in particular ->lock_work
It seems that initalising afs_vnode::lock_work a single time in the slab's
init function isn't sufficient for work_structs. This results in the
DEBUG_OBJECTS debugging stuff producing a warning occasionally when running
the generic/131 xfstest:
ODEBUG: activate not available (active state 0) object: 0000000016d8760f object type: work_struct hint: afs_lock_work+0x0/0x220
WARNING: lib/debugobjects.c:629 at debug_print_object+0x4b/0x90, CPU#3: locktest/7695
...
CPU: 3 UID: 0 PID: 7695 Comm: locktest Tainted: G S 7.1.0-build3+ #2771 PREEMPT
...
RIP: 0010:debug_print_object+0x65/0x90
...
Call Trace:
? __pfx_afs_lock_work+0x10/0x10
debug_object_activate+0x122/0x170
insert_work+0x25/0x60
__queue_work+0x2e0/0x340
queue_delayed_work_on+0x48/0x70
afs_fl_release_private+0x57/0x70
locks_release_private+0x5c/0xa0
locks_free_lock+0xe/0x20
posix_lock_inode+0x55f/0x5b0
locks_lock_inode_wait+0x81/0x140
? file_write_and_wait_range+0x50/0x70
afs_lock+0xcd/0x110
fcntl_setlk+0x10d/0x260
do_fcntl+0x24e/0x5b0
__do_sys_fcntl+0x6a/0x90
do_syscall_64+0x11e/0x310
entry_SYSCALL_64_after_hwframe+0x71/0x79
Fix this by reinitialising ->lock_work after allocating an inode.
Also, flush ->lock_work when the inode is being evicted to make sure it's
not still running.
A flaw was found in the Linux kernel's AFS (Andrew File System) component. This vulnerability arises from improper reinitialization of internal work queue objects, specifically afs_vnode::lock_work. An attacker could potentially exploit this flaw to trigger kernel warnings and lead to system instability, resulting in a denial of service where the system becomes unresponsive.
Отчет
A moderate-impact flaw was found in the Linux kernel AFS (Andrew File System) client shipped in Red Hat Enterprise Linux and Red Hat In-Vehicle OS. The afs_vnode::lock_work delayed work object is initialised only once in the slab constructor instead of being reinitialised each time an inode is allocated, and it is not flushed when an inode is evicted. As a result, the work_struct can be queued in an improper state during file-locking operations on AFS files (for example via fcntl()), which triggers kernel DEBUG_OBJECTS warnings and can lead to system instability. A local user able to perform file-locking operations on an AFS mount could exploit this flaw to cause a denial of service. Red Hat rated the impact as moderate because the demonstrated consequence is limited to availability (CVSS 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H); the higher upstream CVEORG score of 7.8 additionally assumes high confidentiality and integrity impact, which the available evidence does not establish. Red Hat Enterprise Linux 6, 7, and 8 (kernel and kernel-rt) are not affected because the vulnerable code is not present in those streams. For the affected Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 10, and Red Hat In-Vehicle OS streams the fix is deferred: the issue manifests as a debug warning and potential instability under specific local AFS file-locking workloads rather than a demonstrated privilege-escalation or memory-corruption exploit, so it will be addressed in a future planned update. Until then, the residual risk is a local denial of service on systems that actively use AFS filesystems.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: afs: Fix reinitialisation of the inode, in particular ->lock_work It seems that initalising afs_vnode::lock_work a single time in the slab's init function isn't sufficient for work_structs. This results in the DEBUG_OBJECTS debugging stuff producing a warning occasionally when running the generic/131 xfstest: ODEBUG: activate not available (active state 0) object: 0000000016d8760f object type: work_struct hint: afs_lock_work+0x0/0x220 WARNING: lib/debugobjects.c:629 at debug_print_object+0x4b/0x90, CPU#3: locktest/7695 ... CPU: 3 UID: 0 PID: 7695 Comm: locktest Tainted: G S 7.1.0-build3+ #2771 PREEMPT ... RIP: 0010:debug_print_object+0x65/0x90 ... Call Trace: <TASK> ? __pfx_afs_lock_work+0x10/0x10 debug_object_activate+0x122/0x170 insert_work+0x25/0x60 __queue_work+0x2e0/0x340 queue_delayed_work_on+0x48/0x70 afs_fl_release_private+0x57/0x70 locks_release_private+0x5c/0xa0 locks_free_lock+0xe/0x20 posix_lock_inode+0...
In the Linux kernel, the following vulnerability has been resolved: afs: Fix reinitialisation of the inode, in particular ->lock_work It seems that initalising afs_vnode::lock_work a single time in the slab's init function isn't sufficient for work_structs. This results in the DEBUG_OBJECTS debugging stuff producing a warning occasionally when running the generic/131 xfstest: ODEBUG: activate not available (active state 0) object: 0000000016d8760f object type: work_struct hint: afs_lock_work+0x0/0x220 WARNING: lib/debugobjects.c:629 at debug_print_object+0x4b/0x90, CPU#3: locktest/7695 ... CPU: 3 UID: 0 PID: 7695 Comm: locktest Tainted: G S 7.1.0-build3+ #2771 PREEMPT ... RIP: 0010:debug_print_object+0x65/0x90 ... Call Trace: <TASK> ? __pfx_afs_lock_work+0x10/0x10 debug_object_activate+0x122/0x170 insert_work+0x25/0x60 __queue_work+0x2e0/0x340 queue_delayed_work_on+0x48/0x70 afs_fl_release_private+0x57/0x70 locks_release_private+0x5c/0xa0
In the Linux kernel, the following vulnerability has been resolved: a ...
In the Linux kernel, the following vulnerability has been resolved: afs: Fix reinitialisation of the inode, in particular ->lock_work It seems that initalising afs_vnode::lock_work a single time in the slab's init function isn't sufficient for work_structs. This results in the DEBUG_OBJECTS debugging stuff producing a warning occasionally when running the generic/131 xfstest: ODEBUG: activate not available (active state 0) object: 0000000016d8760f object type: work_struct hint: afs_lock_work+0x0/0x220 WARNING: lib/debugobjects.c:629 at debug_print_object+0x4b/0x90, CPU#3: locktest/7695 ... CPU: 3 UID: 0 PID: 7695 Comm: locktest Tainted: G S 7.1.0-build3+ #2771 PREEMPT ... RIP: 0010:debug_print_object+0x65/0x90 ... Call Trace: <TASK> ? __pfx_afs_lock_work+0x10/0x10 debug_object_activate+0x122/0x170 insert_work+0x25/0x60 __queue_work+0x2e0/0x340 queue_delayed_work_on+0x48/0x70 afs_fl_release_private+0x57/0x70 locks_release_private+0x5c/0xa0...
EPSS
5.5 Medium
CVSS3