CVE-2024-50041: i40e: Fix macvlan leak by synchronizing access to mac_filter_hash

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-10-21 · updated 2026-08-04
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix macvlan leak by synchronizing access to mac_filter_hash This patch addresses a macvlan leak issue in the i40e driver caused by concurrent access to vsi->mac_filter_hash. The leak occurs when multiple threads attempt to modify the mac_filter_hash simultaneously, leading to inconsistent state and potential memory leaks. To fix this, we now wrap the calls to i40e_del_mac_filter() and zeroing vf->default_lan_addr.addr with spin_lock/unlock_bh(&vsi->mac_filter_hash_lock), ensuring atomic operations and preventing concurrent access. Additionally, we add lockdep_assert_held(&vsi->mac_filter_hash_lock) in i40e_add_mac_filter() to help catch similar issues in the future. Reproduction steps: 1. Spawn VFs and configure port vlan on them. 2. Trigger concurrent macvlan operations (e.g., adding and deleting portvlan and/or mac filters). 3. Observe the potential memory leak and inconsistent state in the mac_filter_hash. This synchronization ensures the integrity of the mac_filter_hash and prevents the described leak.

Affected products

Linux kernel: from 5.15.54 before 5.15.168; from 5.18.11 before 5.19; from 5.19 before 6.1.113; from 6.2 before 6.6.57; from 6.7 before 6.11.4; 6.12-rc1, 6.12-rc2 — fixed in 5.15.168, 5.19, 6.1.113, 6.11.4, 6.6.57

How to fix

Upgrade to a fixed version: Linux kernel 5.15.168, 5.19, 6.1.113, 6.11.4. Check the vendor advisory for mitigations.

References

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