CVE-2026-53126 blk-cgroup: fix disk reference leak in blkcg_maybe_throttle_current()
A missing disk reference release in the Linux kernel block cgroup throttling code can lead to resource leaks and potential denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53126?
CVE-2026-53126 is a medium-severity memory corruption vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: fix disk reference leak in blkcg_maybe_throttle_current()
Add the missing put_disk() on the error path in blkcg_maybe_throttle_current(). When blkcg lookup, blkg lookup, or blkg_tryget() fails, the function jumps to the out label which only calls rcu_read_unlock() but does not release the disk reference acquired by blkcg_schedule_throttle() via get_device(). Since current->throttle_disk is already set to NULL before the lookup, blkcg_exit() cannot release this reference either, causing the disk to never be freed.
Restore the reference release that was present as blk_put_queue() in the original code but was inadvertently dropped during the conversion from request_queue to gendisk.
Which versions are affected by CVE-2026-53126?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53126?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-53126 being exploited?
There is no known exploitation of CVE-2026-53126 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53126, DEBIAN-CVE-2026-53126, GHSA-2mp2-fxxh-hv2j, UBUNTU-CVE-2026-53126.