CVE-2026-72307

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

mlxsw: fix refcount leak in mlxsw_sp_vrs_lpm_tree_replace()

When mlxsw_sp_vrs_lpm_tree_replace() fails after replacing some VRs,

the error rollback loop does not correctly revert the preceding

replacements. The loop decrements the index but fails to update the

vr pointer, which still points to the VR that caused the failure. As

a result, the condition and the rollback call always operate on the

same VR, potentially calling mlxsw_sp_vr_lpm_tree_replace() multiple

times on it while never rolling back the earlier VRs. Those VRs

continue to hold a reference to new_tree acquired via

mlxsw_sp_lpm_tree_hold(), leaking the reference count of new_tree.

Fix by reinitializing vr inside the error loop with the updated index:

vr = &mlxsw_sp->router->vrs[i];

so that the loop correctly iterates over all VRs that were actually

replaced.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References