Improper resource shutdown or release in Linux kernel - CVE-2026-64509

Vulnerability details

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

The vulnerability exists due to improper resource shutdown in GenDiskBuilder::build() and GenDisk::drop() in rust/kernel/block/mq/gen_disk.rs when handling gendisk cleanup on error and release paths. A local user can trigger the vulnerable cleanup paths to cause a denial of service.

Exploitation requires interacting with the Rust block layer gendisk functionality so that a temporary gendisk and request_queue remain unreleased or the final gendisk reference is not dropped during teardown.

Affected software

How to mitigate CVE-2026-64509

External References

• https://git.kernel.org/stable/c/2957771379fa335103a4b539db57bb2271e12142
• https://git.kernel.org/stable/c/6822a2685b4da9a87efd1fce4b042678a31ff734
• https://git.kernel.org/stable/c/d1dcaa5229a63a6b6df7e0f673fe576cf3d6e8cb
• https://git.kernel.org/stable/c/e7636f26f77070a529c26d65afd217514ce85ce4

Related Security Bulletins

• Improper resource shutdown or release in Linux kernel block mq
• Debian update for linux