SB20260918330 - Improper locking in Linux kernel tty serial driver
Published: September 18, 2026
Security Bulletin ID
SB20260918330
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Partial DoS
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper locking (CVE-ID: CVE-2026-90338)
CWE-ID: CWE-667 - Improper Locking
CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper locking in pl011_console_write_atomic() when processing atomic console writes. A local user can trigger an atomic-context printk while the common-clock enable lock is contended to cause a denial of service.
The condition was reproduced on PREEMPT_RT systems with clock-backed pl011 consoles and may also occur from NMI context.
Remediation
Install update from vendor's website.