CVE-2026-72162 ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
A missing bounds check in the Linux kernel OCFS2 filesystem allows a local attacker to cause a system crash via a crafted disk image.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72162?
CVE-2026-72162 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
[BUG] On-disk corruption setting l_next_free_rec to 0 in an inode's embedded extent list triggers a UBSAN panic on the next write to that file.
[CAUSE] ocfs2_sum_rightmost_rec() computes i = le16_to_cpu(el->l_next_free_rec) - 1 and accesses el->l_recs[i] without validating i. When l_next_free_rec is 0, i becomes -1; when l_next_free_rec exceeds l_count, i falls past the end of the array. Either case violates the __counted_by_le(l_count) annotation on l_recs[] and triggers UBSAN.
[FIX] Validate the inode's embedded extent list when the inode is read, in ocfs2_validate_inode_block(): l_count must be non-zero and no larger than the inode block can hold, and l_next_free_rec must not exceed l_count. A corrupt list is rejected at read time, before the b-tree code can index l_recs[] out of bounds.
Which versions are affected by CVE-2026-72162?
How do I fix CVE-2026-72162?
Apply the vendor's patch.
Is CVE-2026-72162 being exploited?
There is no known exploitation of CVE-2026-72162 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72162, DEBIAN-CVE-2026-72162, GHSA-w4g7-33m6-26g5, UBUNTU-CVE-2026-72162.