perf/x86: Fix NULL event access and potential PEBS record loss
When intel_pmu_drain_pebs_icl() is called to drain PEBS records, the
perf_event_overflow() could be called to process the last PEBS record.
While perf_event_overflow() could trigger the interrupt throttle and
stop all events of the group, like what the below call-chain shows.
perf_event_overflow()
-> __perf_event_overflow()
->__perf_event_account_interrupt()
-> perf_event_throttle_group()
-> perf_event_throttle()
-> event->pmu->stop()
-> x86_pmu_stop()
The side effect of stopping the events is that all corresponding event
pointers in cpuc->events[] array are cleared to NULL.
Assume there are two PEBS events (event a and event b) in a group. When
intel_pmu_drain_pebs_icl() calls perf_event_overflow() to process the
last PEBS record of PEBS event a, interrupt throttle is triggered and
all pointers of event a and event b are cleared to NULL. Then
intel_pmu_drain_pebs_icl() tries to process the last PEBS record of
event b and encounters NULL pointer access.
To avoid this issue, move cpuc->events[] clearing from x86_pmu_stop()
to x86_pmu_del(). It's safe since cpuc->active_mask or
cpuc->pebs_enabled is always checked before access the event pointer
from cpuc->events[].
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
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Tracking
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| Source | ID | Title |
|---|---|---|
Ubuntu USN |
USN-8094-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8094-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8094-3 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-8094-4 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8094-5 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-8152-1 | Linux kernel (OEM) vulnerabilities |
Fri, 26 Dec 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Wed, 24 Dec 2025 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: perf/x86: Fix NULL event access and potential PEBS record loss When intel_pmu_drain_pebs_icl() is called to drain PEBS records, the perf_event_overflow() could be called to process the last PEBS record. While perf_event_overflow() could trigger the interrupt throttle and stop all events of the group, like what the below call-chain shows. perf_event_overflow() -> __perf_event_overflow() ->__perf_event_account_interrupt() -> perf_event_throttle_group() -> perf_event_throttle() -> event->pmu->stop() -> x86_pmu_stop() The side effect of stopping the events is that all corresponding event pointers in cpuc->events[] array are cleared to NULL. Assume there are two PEBS events (event a and event b) in a group. When intel_pmu_drain_pebs_icl() calls perf_event_overflow() to process the last PEBS record of PEBS event a, interrupt throttle is triggered and all pointers of event a and event b are cleared to NULL. Then intel_pmu_drain_pebs_icl() tries to process the last PEBS record of event b and encounters NULL pointer access. To avoid this issue, move cpuc->events[] clearing from x86_pmu_stop() to x86_pmu_del(). It's safe since cpuc->active_mask or cpuc->pebs_enabled is always checked before access the event pointer from cpuc->events[]. | |
| Title | perf/x86: Fix NULL event access and potential PEBS record loss | |
| 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: 2026-05-11T21:51:59.533Z
Reserved: 2025-12-16T14:48:05.310Z
Link: CVE-2025-68375
No data.
Status : Deferred
Published: 2025-12-24T11:16:01.097
Modified: 2026-04-15T00:35:42.020
Link: CVE-2025-68375
OpenCVE Enrichment
No data.
No weakness.
Ubuntu USN