CVE-2026-93275

A flaw was found in the Linux kernel's Intel Processor Trace (PT) subsystem. A local user could trigger a Denial of Service (DoS) condition by executing performance monitoring operations that cause group event throttling. Due to improper state tracking during event start and stop operations, the auxiliary trace buffer fails to balance open and close requests, leading to internal kernel warnings and potential system instability.

A flaw of low impact was found in the Linux kernel's Intel Processor Trace (PT) performance monitoring subsystem. When an Intel PT event is part of an event group that is throttled, the PMU stop/start callbacks are invoked without the PERF_EF_UPDATE flag. This leaves the auxiliary (AUX) trace buffer in an unbalanced open state, so a subsequent event start calls perf_aux_output_begin() while a previous AUX output context is still open, violating the rule against nesting and triggering a kernel WARNING, which can result in denial of service or system instability. A local user with permission to perform perf-based monitoring (for example, an Intel PT event grouped with a sampling event using AUX area sampling) can trigger this condition.

The kernel in Red Hat Enterprise Linux 7, 8, 9, and 10 (including the kernel-rt Real-Time variant), Red Hat In-Vehicle OS, and the RHEL CoreOS kernels shipped with Red Hat OpenShift Container Platform 4 and 5 are affected. Red Hat Enterprise Linux 6 is not affected because the vulnerable code is not present in that release.

Although the CVSS:3.1 base score is 5.5 (Moderate), Red Hat rates the impact of this flaw as low: exploitation requires hardware with Intel PT support, an Intel PT event grouped with another event, and a throttling condition to occur, and the direct consequence is a kernel WARNING and disruption of tracing rather than memory corruption, information disclosure, or privilege escalation. Because of the low impact, fixes for affected products are deferred to a future release; the residual risk is that a local user able to run perf monitoring with Intel PT could trigger the kernel WARNING and potential system instability.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.