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[].
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[].
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
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 |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-12-24T10:33:04.819Z
Reserved: 2025-12-16T14:48:05.310Z
Link: CVE-2025-68375
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-12-24T11:16:01.097
Modified: 2025-12-24T11:16:01.097
Link: CVE-2025-68375
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.