CVEvulnerability
CVE-2025-68771
- Status
- Deferred
- Published
- 2026-01-13
- Last modified
- 2026-06-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix kernel BUG in ocfs2_find_victim_chain
syzbot reported a kernel BUG in ocfs2_find_victim_chain() because the
`cl_next_free_rec` field of the allocation chain list (next free slot in
the chain list) is 0, triggring the BUG_ON(!cl->cl_next_free_rec)
condition in ocfs2_find_victim_chain() and panicking the kernel.
To fix this, an if condition is introduced in ocfs2_claim_suballoc_bits(),
just before calling ocfs2_find_victim_chain(), the code block in it being
executed when either of the following conditions is true:
1. `cl_next_free_rec` is equal to 0, indicating that there are no free
chains in the allocation chain list
2. `cl_next_free_rec` is greater than `cl_count` (the total number of
chains in the allocation chain list)
Either of them being true is indicative of the fact that there are no
chains left for usage.
This is addressed using ocfs2_error(), which prints
the error log for debugging purposes, rather than panicking the kernel.
References
- https://git.kernel.org/stable/c/039bef30e320827bac8990c9f29d2a68cd8adb5f git.kernel.org
- https://git.kernel.org/stable/c/1f77e5cd563e6387fdf3bb714fcda36cd88ac5e7 git.kernel.org
- https://git.kernel.org/stable/c/7acc0390e0dd7474c4451d05465a677d55ad4268 git.kernel.org
- https://git.kernel.org/stable/c/96f1b074c98c20f55a3b23d2ab44d9fb0f619869 git.kernel.org
- https://git.kernel.org/stable/c/b08a33d5f80efe6979a6e8f905c1a898910c21dd git.kernel.org
- https://git.kernel.org/stable/c/d0fd1f732ea8063cecd07a3879b7d815c7ee71ed git.kernel.org
- https://git.kernel.org/stable/c/e24aedae71652d4119049f1fbef6532ccbe3966d git.kernel.org