Deadlock in Linux kernel - CVE-2026-90209
Published: September 18, 2026
Vulnerability identifier: #VU151267
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-90209
CWE-ID: CWE-833
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper locking in the s390 debug subsystem's debug area unregistration handling when a debugfs file associated with a debug area is written concurrently with debug area unregistration. A local user can write to an associated debugfs file while debug area unregistration occurs to cause a denial of service.
Affected software
Linux kernel
How to mitigate CVE-2026-90209
Install security update from vendor's repository.
External References
- https://git.kernel.org/stable/c/183f8f6d64bb0510070c856b9927618c53014a7b
- https://git.kernel.org/stable/c/445c31ac638fd1af203d79bdf25fc0cb3149fbbc
- https://git.kernel.org/stable/c/45bb341d1b73eb293e0dd43d9b72bbc8b615d0ba
- https://git.kernel.org/stable/c/54e1259b75d6402a1d0cfb822b9bb2c507e53dab
- https://git.kernel.org/stable/c/5d83f3faa3fb7f23f298cfd40382611999de5d1d
- https://git.kernel.org/stable/c/a08b70ed2d1ec907353a72f15163b8e34ff4b2f8
- https://git.kernel.org/stable/c/a214c3dacc779b2afcb0ac9c8001e45ee4ffb2ed