CVE-2026-74734

A flaw was found in the Linux kernel's FireWire (IEEE 1394) Open Host Controller Interface (OHCI) driver. During the error handling path of the driver's probe function, a NULL pointer dereference can occur in the ar_context_release() function if the context was not properly initialized. This vulnerability can be triggered by a local attacker under specific hardware conditions, leading to a system crash and resulting in a Denial of Service (DoS).

Red Hat Product Security has rated this issue as having Low security impact. A NULL pointer dereference flaw was found in the Linux kernel's FireWire (IEEE 1394) Open Host Controller Interface (OHCI) driver. If the driver's PCI probe function fails early (for example, when pcim_enable_device() or MMIO mapping fails), the device resource (devres) cleanup path invokes release_ohci(), which unconditionally calls ar_context_release(). When the asynchronous receive context was never initialized, ctx->ohci remains NULL, and ar_context_release() dereferences it before checking whether the context was initialized. A local attacker able to trigger the driver's probe error path under specific hardware conditions could use this flaw to crash the kernel, resulting in a denial of service. The flaw affects only system availability; there is no impact on confidentiality or integrity.

Red Hat Enterprise Linux and Red Hat In-Vehicle OS kernels shipped in currently supported streams are not affected by this flaw because the vulnerable code is not present in those kernels. Red Hat Enterprise Linux 6 Extended Lifecycle Support is out of support scope, so this flaw will not be addressed for that stream.

Red Hat's Low impact rating reflects that, although the CVSS:3.1 base score of 5.5 (Moderate) captures the high availability impact, exploitation requires local privileged access to trigger PCI device probing, depends on specific hardware conditions, and the sole consequence is a system crash (denial of service).

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.