In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()
The finalization of nilfs_segctor_thread() can race with
nilfs_segctor_kill_thread() which terminates that thread, potentially
causing a use-after-free BUG as KASAN detected.
At the end of nilfs_segctor_thread(), it assigns NULL to "sc_task" member
of "struct nilfs_sc_info" to indicate the thread has finished, and then
notifies nilfs_segctor_kill_thread() of this using waitqueue
"sc_wait_task" on the struct nilfs_sc_info.
However, here, immediately after the NULL assignment to "sc_task", it is
possible that nilfs_segctor_kill_thread() will detect it and return to
continue the deallocation, freeing the nilfs_sc_info structure before the
thread does the notification.
This fixes the issue by protecting the NULL assignment to "sc_task" and
its notification, with spinlock "sc_state_lock" of the struct
nilfs_sc_info. Since nilfs_segctor_kill_thread() does a final check to
see if "sc_task" is NULL with "sc_state_lock" locked, this can eliminate
the race.
Metrics
Affected Vendors & Products
References
History
Sat, 04 Oct 2025 16:00:00 +0000
Type | Values Removed | Values Added |
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Description | In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread() The finalization of nilfs_segctor_thread() can race with nilfs_segctor_kill_thread() which terminates that thread, potentially causing a use-after-free BUG as KASAN detected. At the end of nilfs_segctor_thread(), it assigns NULL to "sc_task" member of "struct nilfs_sc_info" to indicate the thread has finished, and then notifies nilfs_segctor_kill_thread() of this using waitqueue "sc_wait_task" on the struct nilfs_sc_info. However, here, immediately after the NULL assignment to "sc_task", it is possible that nilfs_segctor_kill_thread() will detect it and return to continue the deallocation, freeing the nilfs_sc_info structure before the thread does the notification. This fixes the issue by protecting the NULL assignment to "sc_task" and its notification, with spinlock "sc_state_lock" of the struct nilfs_sc_info. Since nilfs_segctor_kill_thread() does a final check to see if "sc_task" is NULL with "sc_state_lock" locked, this can eliminate the race. | |
Title | nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread() | |
References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-04T15:44:17.302Z
Reserved: 2025-10-04T15:40:38.480Z
Link: CVE-2023-53608

No data.

Status : Received
Published: 2025-10-04T16:15:57.527
Modified: 2025-10-04T16:15:57.527
Link: CVE-2023-53608

No data.

No data.