Description
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 ]
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 ]
Published:
2026-08-26
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis and contextual insights are available on OpenCVE Cloud.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
No advisories yet.
References
History
Wed, 26 Aug 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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 ] | |
| Title | rseq: Prevent hard lockup on granted time slice extension | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-26T14:36:57.763Z
Reserved: 2026-08-15T05:44:03.931Z
Link: CVE-2026-74749
No data.
Status : Received
Published: 2026-08-26T15:16:53.933
Modified: 2026-08-26T15:16:53.933
Link: CVE-2026-74749
No data.
OpenCVE Enrichment
Updated: 2026-08-26T16:00:07Z
Weaknesses
No weakness.