CVE-2026-63973 net: mana: Add NULL guards in teardown path to prevent panic on attach failure
A missing NULL check in the Linux kernel's mana network driver can cause a system panic during queue allocation failure, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-63973?
CVE-2026-63973 is a medium-severity vulnerability in Linux kernel, published on 19 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-476
Which versions are affected by CVE-2026-63973?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-63973?
Apply the vendor's patch.
Is CVE-2026-63973 being exploited?
There is no known exploitation of CVE-2026-63973 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-63973, DEBIAN-CVE-2026-63973, GHSA-fcq8-57fg-2mm8, ROOT-OS-UBUNTU-2204-CVE-2026-63973, UBUNTU-CVE-2026-63973.