CVE-2026-63973: net: mana: Add NULL guards in teardown path to prevent panic on attach failure

Vulnerability summary

CVE-2026-63973 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.7% of scored vulnerabilities.

Timeline

1. 19-07-2026
   PublishedVulnerability first disclosed.

Description

In the Linux kernel, the following vulnerability has been resolved: net: mana: Add NULL guards in teardown path to prevent panic on attach failure When queue allocation fails partway through, the error cleanup frees and NULLs apc->tx_qp and apc->rxqs. Multiple teardown paths such as mana_remove(), mana_change_mtu() recovery, and internal error handling in mana_alloc_queues() can subsequently call into functions that dereference these pointers without NULL checks: - mana_chn_setxdp() dereferences apc->rxqs[0], causing a NULL pointer dereference panic (CR2: 0000000000000000 at mana_chn_setxdp+0x26). - mana_destroy_vport() iterates apc->rxqs without a NULL check. - mana_fence_rqs() iterates apc->rxqs without a NULL check. - mana_dealloc_queues() iterates apc->tx_qp without a NULL check. Add NULL guards for apc->rxqs in mana_fence_rqs(), mana_destroy_vport(), and before the mana_chn_setxdp() call. Add a NULL guard for apc->tx_qp in mana_dealloc_queues() to skip TX queue draining when TX queues were never allocated or already freed.

• CWE-476NULL Pointer DereferenceThe product dereferences a pointer that it expects to be valid but is NULL.