CVE-2026-53230: net/mlx5: Fix slab-out-of-bounds in mlx5_query_nic_vport_mac_list
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Fix slab-out-of-bounds in mlx5querynicvportmaclist
mlx5querynicvportmaclist() sizes its firmware command buffer using the PF's logmaxcurrentuc/mclist capabilities. When querying a VF vport with a larger configured max (via devlink), the firmware response can overflow this buffer:
BUG: KASAN: slab-out-of-bounds in mlx5querynicvportmaclist+0x453/0x4c0 [mlx5core] Read of size 4 at addr ff1100013ffc8a12 by task kworker/u96:2/385
CPU: 12 UID: 0 PID: 385 Comm: kworker/u96:2 Not tainted 7.0.0-rc6+ #1 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) Workqueue: mlx5eswwq eswvportchangehandler [mlx5core] Call Trace: <TASK> dumpstacklvl+0x69/0xa0 printreport+0x176/0x4e4 kasanreport+0xc8/0x100 mlx5querynicvportmaclist+0x453/0x4c0 [mlx5core] eswupdatevportaddrlist+0x2e3/0xda0 [mlx5core] eswvportchangehandlelocked+0xa1f/0x1060 [mlx5core] eswvportchangehandler+0x6a/0x90 [mlx5core] processonework+0x87f/0x15e0 workerthread+0x62b/0x1020 kthread+0x375/0x490 retfromfork+0x4dc/0x810 retfromforkasm+0x11/0x20 </TASK>
Fix by querying the vport's own HCA caps to size the buffer correctly. Refactor the function to allocate and return the MAC list internally, removing the caller's dependency on knowing the correct max.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.143.1-1 - Upgrade
Upgrade
mlx5_coreto a version that resolves this vulnerability.Patch net/mlx5: Fix slab-out-of-bounds in mlx5_query_nic_vport_mac_list
Event History
Frequently Asked Questions
What is the severity of CVE-2026-53230?
CVE-2026-53230 has a high severity rating of 8.7.
How do I fix CVE-2026-53230?
To fix CVE-2026-53230, update the Linux kernel to the patched version that addresses the slab-out-of-bounds vulnerability.
What software is affected by CVE-2026-53230?
CVE-2026-53230 affects the Linux kernel and specifically the mlx5_core driver.
What does CVE-2026-53230 exploit?
CVE-2026-53230 exploits a slab-out-of-bounds condition when querying a VF vport's MAC list.
When was CVE-2026-53230 published?
CVE-2026-53230 was published on June 25, 2026.