Use-after-free in Linux kernel - CVE-2026-74518

Vulnerability details

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

The vulnerability exists due to use-after-free in allocate_file_region_entries() when handling concurrent region cache operations on a shared resv_map. A local user can trigger concurrent region_chg()/region_add()/region_del() activity on the same shared mapping to cause a denial of service.

The issue occurs in shared hugetlbfs mappings and was observed when multiple mappers accessed the same hugetlbfs inode concurrently.

Affected software

How to mitigate CVE-2026-74518

External References

• https://git.kernel.org/stable/c/126a70bf1a08ddc9d79c471ebdaa2b08cfbab8df
• https://git.kernel.org/stable/c/587a0accc2b4fccc5cf7baf0fe34e50efde51f9c
• https://git.kernel.org/stable/c/62e1c2741a4d923d9854efd5927a6212aad7a187
• https://git.kernel.org/stable/c/ac1bb7fd45088d0db57a22ce7729f258ebd63cf5
• https://git.kernel.org/stable/c/dd9623f58ec702a07b2d67179d6fcea79c52231a

Related Security Bulletins

• Use-after-free in Linux kernel mm
• Debian update for linux