CVE-2023-54209 block: fix blktrace debugfs entries leakage
A local attacker can leak debugfs entries by enabling blktrace via ioctl after disk deletion, potentially causing resource exhaustion.
- 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-2023-54209?
CVE-2023-54209 is a denial of service vulnerability in Linux, published on 30 Dec 2025. 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:
block: fix blktrace debugfs entries leakage
Commit 99d055b4fd4b ("block: remove per-disk debugfs files in blk_unregister_queue") moves blk_trace_shutdown() from blk_release_queue() to blk_unregister_queue(), this is safe if blktrace is created through sysfs, however, there is a regression in corner case.
blktrace can still be enabled after del_gendisk() through ioctl if the disk is opened before del_gendisk(), and if blktrace is not shutdown through ioctl before closing the disk, debugfs entries will be leaked.
Fix this problem by shutdown blktrace in disk_release(), this is safe because blk_trace_remove() is reentrant.
Which versions are affected by CVE-2023-54209?
How do I fix CVE-2023-54209?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-54209 being exploited?
There is no known exploitation of CVE-2023-54209 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54209, DEBIAN-CVE-2023-54209, GHSA-mxfp-7rqw-mqhc, UBUNTU-CVE-2023-54209.