SB20261103130 - Race condition in Linux kernel printk

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-99250)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 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]

The vulnerability allows a local user to potentially cause a denial of service by triggering a system hang during boot.

The vulnerability exists due to improper synchronization in the Linux kernel printk subsystem when console-printing kernel threads asynchronously enable and disable interrupts during early SMP initialization. A local user can potentially trigger the affected startup sequence to cause a boot-time hang on susceptible hardware using NBCON consoles.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/5f339c46f153184570f16c8e789c9709b14cbe8b
• https://git.kernel.org/stable/c/7595bacee48bc30b5021eccf199d704d4e5e5374
• https://git.kernel.org/stable/c/792acd173da0884f0172c68cb473f42cf93c647e
• https://git.kernel.org/stable/c/a86bcdd84c8fe7a45f73e12d53fe06fea07d1ceb