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.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
||||||||||||||||||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
No advisories yet.
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | s390/debug: Fix deadlock during unregister | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:07:24.126Z
Reserved: 2026-09-11T19:38:34.793Z
Link: CVE-2026-90209
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:17:16.060
Modified: 2026-09-17T17:17:16.060
Link: CVE-2026-90209
Redhat
No data.
OpenCVE Enrichment
No data.
No weakness.