CVE Catalog

CVE-2026-99250

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the NBCON console printing kthreads are started very early during boot via early_initcall(). Asynchronously enabling/disabling interrupts during early boot may interfere with early SMP setup on some hardware platforms, causing hangs. The fix postpones kthread startup until after all arch initcalls have completed.

Risk Assessment

On some SMP systems, boot may hang due to missed IPIs. The issue can prevent the system from booting, which is especially disruptive in production environments.

Recommendation

Update the Linux kernel to a version containing the fix that postpones NBCON kthread startup. Higher priority for SMP systems that have reported boot hang issues.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: printk: Postpone kthread startup There have been various bug reports related to SMP systems hanging on boot. The reports vary but seem to have some overlap with regard to missed IPI's during SMP setup. The reports also show that reverting NBCON console usage allows the bugs to disappear. The NBCON kthreads for console printing are started very early during boot using early_initcall(). Since these kthreads are asynchronously enabling/disabling interrupts during early boot, they may be interfering with early SMP setup on some hardware platforms. Starting the console printing kthreads later has shown to avoid the hanging on systems that could previously reproduce the issue. Postpone kthread starting until after all arch initcalls have completed.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS