CVE-2026-90209 in Linux
Sumário
de MITRE • 17/09/2026
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.
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