About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

s390/debug: Fix deadlock during unregister

Unregistering an s390dbf debug area while one of the associated debugfs files is being written to can cause a deadlock:

$ echo >…/vmur/level $ rmmod vmur

debugfs write debugfs_file_get() debug_unregister() mutex_lock(debug_mutex) debugfs_remove() wait for debugfs_file_put() debug_file_ops.write() debug_input() mutex_lock(debug_mutex) ==> DEADLOCK

Fix this by splitting debug_unregister() into an s390dbf and debugfs part, and running only the s390dbf part with debug_mutex locked.

Affected product:

AlmaLinux 9.2 ESU , Debian 11 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU

Affected packages:

linux @ 5.10.259 (+3 more)

Live-patch status from KernelCare for each operating system.