CVE-2023-54209

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.

For the CVSS the PR is set to L because triggering the issue requires local access and the ability to open a block device and issue ioctls to enable blktrace. On many systems that capability is available to unprivileged users only for some devices or is restricted by device permissions. The primary impact is a resource leak in debugfs which can accumulate and contribute to memory or namespace exhaustion.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.