CVE-2026-53261
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
In the Linux kernel, a vulnerability in the devlink mechanism causes a nested relation to not be released when a devlink instance fails before registration. This results in a memory leak of the devlink->rel structure.
Risk Assessment
Memory leak may lead to gradual resource exhaustion, especially in environments heavily using SF (Sub-Function) features, potentially causing performance degradation or system crashes.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit that releases the relation in devlink_free()). Prioritize production systems using devlink and SF.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: devlink: Release nested relation on devlink free devlink relation state is normally released from devl_unregister(), which calls devlink_rel_put(). This misses devlink instances that get a nested relation before registration and then fail probe before devl_register() is reached. That flow can happen for SFs. The child devlink gets linked to its parent before registration, then a later probe error calls devlink_free() directly. Since the instance was never registered, devl_unregister() is not called and devlink->rel is leaked. Release any pending relation from devlink_free() as well. The registered path is unchanged because devl_unregister() already clears devlink->rel before devlink_free() runs.