SB20260824242 - Race condition in Linux kernel verity

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-74590)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

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.

Remediation

Install update from vendor's website.

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