CVE-2026-74636

A flaw was found in the Linux kernel. A race condition exists between the update_event_fields and event_define_fields functions within the tracing subsystem. A local user, by loading specific modules, could exploit this unprotected access to kernel fields. This could lead to a kernel panic, resulting in a denial of service.

A low impact race condition flaw was found in the Linux kernel tracing subsystem. When two kernel modules are loaded concurrently, event_define_fields() can add fields to the class->fields list while update_event_fields(), called from trace_event_update_all(), traverses the same list without the protection of event_mutex. A local user with the ability to load kernel modules could exploit this race condition to cause a kernel panic, resulting in a denial of service. There is no impact to confidentiality or integrity. The vulnerable code was introduced into Red Hat Enterprise Linux by a downstream change that first shipped in RHEL 9.9, so Red Hat Enterprise Linux 7, 8, and the earlier Red Hat Enterprise Linux 9 update streams are not affected because the vulnerable code is not present; Red Hat Enterprise Linux 6 is out of support scope. The flaw affects the kernel in Red Hat Enterprise Linux 9.9 and Red Hat Enterprise Linux 10, and the kernel and kernel-ivos-qualcomm components in Red Hat In-Vehicle OS 2. For the affected products, the fix has been deferred to a future update because the flaw is rated low impact and its exploitation requires local access with the ability to load kernel modules; the residual risk is limited to a local denial of service (kernel panic). This differs from the CVSS:3.1 base score of 5.5 (Moderate), as Red Hat rates the impact Low because reliable triggering requires privileged local module-loading activity and only system availability is affected.

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.