CVE-2026-99051 fsverity: RCU-delay the freeing of struct fsverity_info
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-99051?
CVE-2026-99051 is a high-severity vulnerability in Linux, published on 23 Oct 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
fsverity: RCU-delay the freeing of struct fsverity_info
__fsverity_get_info() calls rhashtable_lookup_fast(), which just uses rcu_read_lock() and doesn't directly synchronize with fsverity_remove_info().
For the same inode this isn't a problem: its fsverity_info is removed only at inode eviction time or upon failure to enable verity, when the inode no longer needs its fsverity_info and it will no longer be accessed via that inode.
However, this is broken and can cause a use-after-free for concurrent __fsverity_get_info() for *different* inodes. Those rely on following fsverity_info::rhash_head in the rhashtable under rcu_read_lock() only. They also use fsverity_info::inode to do the key comparison.
Fix this by RCU-delaying the freeing of 'struct fsverity_info' after it's been removed from the rhashtable.
Which versions are affected by CVE-2026-99051?
How do I fix CVE-2026-99051?
Upgrade to a fixed version.
Is CVE-2026-99051 being exploited?
There is no known exploitation of CVE-2026-99051 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-99051, GHSA-7hq4-c7jg-2h9h, UBUNTU-CVE-2026-99051.