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.

References 4

• git.kernel.org https://git.kernel.org/stable/c/7149e57cf01184fba175589f8fbe9fbf33be02e1
• git.kernel.org https://git.kernel.org/stable/c/942e81650b81b4ca62f1d8c61de455c9e7c7e6ca
• git.kernel.org https://git.kernel.org/stable/c/aa07e56c6a9c7558165690d14eed4fe8babf34fb
• git.kernel.org https://git.kernel.org/stable/c/dd7de3704af9989b780693d51eaea49a665bd9c2

Remediation