Описание
In the Linux kernel, the following vulnerability has been resolved:
fs: quota: create dedicated workqueue for quota_release_work
There is a kernel panic due to WARN_ONCE when panic_on_warn is set.
This issue occurs when writeback is triggered due to sync call for an
opened file(ie, writeback reason is WB_REASON_SYNC). When f2fs balance
is needed at sync path, flush for quota_release_work is triggered.
By default quota_release_work is queued to "events_unbound" queue which
does not have WQ_MEM_RECLAIM flag. During f2fs balance "writeback"
workqueue tries to flush quota_release_work causing kernel panic due to
MEM_RECLAIM flag mismatch errors.
This patch creates dedicated workqueue with WQ_MEM_RECLAIM flag
for work quota_release_work.
------------[ cut here ]------------
WARNING: CPU: 4 PID: 14867 at kernel/workqueue.c:3721 check_flush_dependency+0x13c/0x148
Call trace:
check_flush_dependency+0x13c/0x148
__flush_work+0xd0/0x398
flush_delayed_work+0x44/0x5c
dquot_writeback_dquots+0x54/0x318
f2fs_do_quota_sync+0xb8/0x1a8
f2fs_write_checkpoint+0x3cc/0x99c
f2fs_gc+0x190/0x750
f2fs_balance_fs+0x110/0x168
f2fs_write_single_data_page+0x474/0x7dc
f2fs_write_data_pages+0x7d0/0xd0c
do_writepages+0xe0/0x2f4
__writeback_single_inode+0x44/0x4ac
writeback_sb_inodes+0x30c/0x538
wb_writeback+0xf4/0x440
wb_workfn+0x128/0x5d4
process_scheduled_works+0x1c4/0x45c
worker_thread+0x32c/0x3e8
kthread+0x11c/0x1b0
ret_from_fork+0x10/0x20
Kernel panic - not syncing: kernel: panic_on_warn set ...
A workqueue configuration mismatch was found in the Linux kernel's filesystem quota subsystem during writeback operations. A local user can trigger this issue when f2fs filesystem balancing initiates quota writeback during sync operations, causing the writeback workqueue to flush quota_release_work from the events_unbound queue. Since events_unbound lacks the WQ_MEM_RECLAIM flag while the writeback queue has it, this flag mismatch triggers workqueue dependency warnings and causes kernel panic when panic_on_warn is enabled, resulting in denial of service.
Отчет
Quota release work is queued to events_unbound (no WQ_MEM_RECLAIM flag) but gets flushed during f2fs writeback from a WQ_MEM_RECLAIM context. This flag mismatch triggers workqueue dependency checks that warn about potential deadlocks—if memory reclaim needs the work to complete but the work needs memory, deadlock could occur. Systems with panic_on_warn turn this warning into a hard panic. The fix creates a dedicated quota workqueue with the proper WQ_MEM_RECLAIM flag.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| 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 | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected |
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Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: fs: quota: create dedicated workqueue for quota_release_work There is a kernel panic due to WARN_ONCE when panic_on_warn is set. This issue occurs when writeback is triggered due to sync call for an opened file(ie, writeback reason is WB_REASON_SYNC). When f2fs balance is needed at sync path, flush for quota_release_work is triggered. By default quota_release_work is queued to "events_unbound" queue which does not have WQ_MEM_RECLAIM flag. During f2fs balance "writeback" workqueue tries to flush quota_release_work causing kernel panic due to MEM_RECLAIM flag mismatch errors. This patch creates dedicated workqueue with WQ_MEM_RECLAIM flag for work quota_release_work. ------------[ cut here ]------------ WARNING: CPU: 4 PID: 14867 at kernel/workqueue.c:3721 check_flush_dependency+0x13c/0x148 Call trace: check_flush_dependency+0x13c/0x148 __flush_work+0xd0/0x398 flush_delayed_work+0x44/0x5c dquot_writeback_dquots+0x54/...
In the Linux kernel, the following vulnerability has been resolved: fs: quota: create dedicated workqueue for quota_release_work There is a kernel panic due to WARN_ONCE when panic_on_warn is set. This issue occurs when writeback is triggered due to sync call for an opened file(ie, writeback reason is WB_REASON_SYNC). When f2fs balance is needed at sync path, flush for quota_release_work is triggered. By default quota_release_work is queued to "events_unbound" queue which does not have WQ_MEM_RECLAIM flag. During f2fs balance "writeback" workqueue tries to flush quota_release_work causing kernel panic due to MEM_RECLAIM flag mismatch errors. This patch creates dedicated workqueue with WQ_MEM_RECLAIM flag for work quota_release_work. ------------[ cut here ]------------ WARNING: CPU: 4 PID: 14867 at kernel/workqueue.c:3721 check_flush_dependency+0x13c/0x148 Call trace: check_flush_dependency+0x13c/0x148 __flush_work+0xd0/0x398 flush_delayed_work+0x44/0x5c dquot_writeback_dquots
In the Linux kernel, the following vulnerability has been resolved: f ...
In the Linux kernel, the following vulnerability has been resolved: fs: quota: create dedicated workqueue for quota_release_work There is a kernel panic due to WARN_ONCE when panic_on_warn is set. This issue occurs when writeback is triggered due to sync call for an opened file(ie, writeback reason is WB_REASON_SYNC). When f2fs balance is needed at sync path, flush for quota_release_work is triggered. By default quota_release_work is queued to "events_unbound" queue which does not have WQ_MEM_RECLAIM flag. During f2fs balance "writeback" workqueue tries to flush quota_release_work causing kernel panic due to MEM_RECLAIM flag mismatch errors. This patch creates dedicated workqueue with WQ_MEM_RECLAIM flag for work quota_release_work. ------------[ cut here ]------------ WARNING: CPU: 4 PID: 14867 at kernel/workqueue.c:3721 check_flush_dependency+0x13c/0x148 Call trace: check_flush_dependency+0x13c/0x148 __flush_work+0xd0/0x398 flush_delayed_work+0x44/0x5c dquot_writeback_dqu...
Уязвимость функций dqput() и dquot_init() ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании
5.5 Medium
CVSS3