CVE-2023-53608

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.

• linux linux kernel (>= 2.6.30 < 4.14.313) • linux linux kernel (>= 4.15 < 4.19.281) • linux linux kernel (>= 4.20 < 5.4.241) • linux linux kernel (>= 5.5 < 5.10.178) • linux linux kernel (>= 5.11 < 5.15.107) • linux linux kernel (>= 5.16 < 6.1.24) • linux linux kernel (>= 6.2 < 6.2.11) • linux linux kernel 6.3