CVE-2026-53067

A flaw was found in the Linux kernel's PCI (Peripheral Component Interconnect) endpoint Message Signaled Interrupts (MSI) doorbell allocation. When MSI allocation fails, the system may attempt to free already freed memory, leading to a double-free vulnerability. This issue can result in memory corruption or a denial of service (DoS) condition, making the system unstable or unresponsive. Additionally, improper handling of already allocated doorbells could lead to memory leaks or overwriting existing allocations.

This vulnerability is rated as Moderate severity because triggering the error unwind failure requires local administrative access to configure PCI endpoint functions, restricting the potential blast radius to local denial of service or memory corruption. Supported Red Hat Enterprise Linux distributions are not affected by this issue, as the underlying endpoint MSI doorbell code introduced in upstream kernel 6.17 is not present in Red Hat kernels.

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.