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Fencer Vulns
no cvss —

CVE-2026-74749 json

rseq: Prevent hard lockup on granted time slice extension

published 2026-08-26 2 mo ago modified 2026-08-26 2 mo ago also EUVD-2026-66579

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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 ]

Patch / fix

  • Linux Linux 7.1.10, 7.2
  • linux Debian 14 7.1.10-1

debian advisories DEBIAN-CVE-2026-74749

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-74749 updated cvss 5.5

kernel: rseq: Prevent hard lockup on granted time slice extension

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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