CVE-2026-43013: net/mlx5: lag: Check for LAG device before creating debugfs

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-01 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: lag: Check for LAG device before creating debugfs __mlx5_lag_dev_add_mdev() may return 0 (success) even when an error occurs that is handled gracefully. Consequently, the initialization flow proceeds to call mlx5_ldev_add_debugfs() even when there is no valid LAG context. mlx5_ldev_add_debugfs() blindly created the debugfs directory and attributes. This exposed interfaces (like the members file) that rely on a valid ldev pointer, leading to potential NULL pointer dereferences if accessed when ldev is NULL. Add a check to verify that mlx5_lag_dev(dev) returns a valid pointer before attempting to create the debugfs entries.

Affected products

Linux kernel: from 5.19 before 6.1.168; from 6.2 before 6.6.134; from 6.7 before 6.12.81; from 6.13 before 6.18.22; from 6.19 before 6.19.12; 7.0-rc1, 7.0-rc2, 7.0-rc3, 7.0-rc4, 7.0-rc5, 7.0-rc6 — fixed in 6.1.168, 6.12.81, 6.18.22, 6.19.12, 6.6.134

How to fix

Upgrade to a fixed version: Linux kernel 6.1.168, 6.12.81, 6.18.22, 6.19.12. Check the vendor advisory for mitigations.

References

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