Race condition in Linux kernel - CVE-2026-74590

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to concurrent modification handling in bpf_get_fsverity_digest() when processing a dynptr-backed fsverity digest buffer. A local user can trigger the kfunc with a concurrently modified digest_size field to cause a denial of service.

The issue arises because the dynptr abstraction ensures memory validity but not stability of its contents during concurrent access.

Affected software

How to mitigate CVE-2026-74590

External References

• https://git.kernel.org/stable/c/1344b632cb5043e32939a84568125719111c5af3
• https://git.kernel.org/stable/c/2a5cfcad1d56e26d645b7887b0ed24c371851525
• https://git.kernel.org/stable/c/3e8ec7c0387273329374f5c7bd61f5f38af71fe1
• https://git.kernel.org/stable/c/5bd63cad9df4328a184c409fbdad4f17944bcdb8

Related Security Bulletins

• Race condition in Linux kernel verity
• Debian update for linux