CVE-2026-97552 xfs: initialise error in xfs_defer_finish_one()
Uninitialized variable in XFS online repair can cause kernel shutdown, leading to denial of service on systems with CONFIG_XFS_ONLINE_REPAIR enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97552?
CVE-2026-97552 is a denial of service vulnerability in Linux, published on 25 Sep 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:
xfs: initialise error in xfs_defer_finish_one()
xfs_defer_finish_one() declares error without an initialiser and only assigns it inside the loop over dfp->dfp_work. When that list is empty the loop body never runs, control falls through to the "Done with the dfp, free it" path, and the function returns an indeterminate value.
An item-less pending item reaches this through xfs_defer_add_barrier(), which xfs_reap_ag_blocks() uses on any CONFIG_XFS_ONLINE_REPAIR kernel. xfs_defer_finish_noroll() treats any non-EAGAIN return as fatal, so a non-zero stack value turns a successful barrier into a SHUTDOWN_CORRUPT_INCORE in the middle of a repair. Zero is the correct result: reaching the free path means the item loop drained without a non-zero error.
Which versions are affected by CVE-2026-97552?
How do I fix CVE-2026-97552?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-97552 being exploited?
There is no known exploitation of CVE-2026-97552 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-97552, DEBIAN-CVE-2026-97552, GHSA-8vjw-786p-wjm9, UBUNTU-CVE-2026-97552.