CVE Catalog

CVE-2026-74749

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel's rseq mechanism, rseq_grant_timeslice_extension() calls hrtimer_rearm_deferred_tif() with interrupts enabled, while __hrtimer_rearm_deferred() expects interrupts disabled. This can lead to a livelock and is caught by lockdep.

Risk Assessment

The vulnerability may cause system hang (livelock) or improper timer operation, potentially leading to system crash or unresponsiveness.

Recommendation

Install a Linux kernel patch that disables interrupts around the invocation of hrtimer_rearm_deferred_tif() in rseq_grant_timeslice_extension().

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: rseq: Prevent hard lockup on granted time slice extension __exit_to_user_mode_loop() invokes rseq_grant_timeslice_extension() with interrupts enabled. If the extension is granted it invokes hrtimer_rearm_deferred_tif() to ensure that a pending deferred hrtimer rearm is handled before exiting to user space. Though this invokes __hrtimer_rearm_deferred() which expects to be invoked with interrupts disabled as it takes hrtimer_cpu_base::lock with raw_spin_lock(). That's a livelock waiting to happen and caught by lockdep: WARNING: ./include/linux/hrtimer_rearm.h:17 at irqentry_exit, CPU#1: slice_test WARNING: inconsistent lock state inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. Prevent this by disabling interrupts around the invocation of hrtimer_rearm_deferred_tif() in rseq_grant_timeslice_extension(). [ tglx: Massaged change log ]

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