CVE-2025-68779: net/mlx5e: Avoid unregistering PSP twice

Severity: unknown
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: 2026-01-13 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Avoid unregistering PSP twice PSP is unregistered twice in: _mlx5e_remove -> mlx5e_psp_unregister mlx5e_nic_cleanup -> mlx5e_psp_unregister This leads to a refcount underflow in some conditions: ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 1694 at lib/refcount.c:28 refcount_warn_saturate+0xd8/0xe0 [...] mlx5e_psp_unregister+0x26/0x50 [mlx5_core] mlx5e_nic_cleanup+0x26/0x90 [mlx5_core] mlx5e_remove+0xe6/0x1f0 [mlx5_core] auxiliary_bus_remove+0x18/0x30 device_release_driver_internal+0x194/0x1f0 bus_remove_device+0xc6/0x130 device_del+0x159/0x3c0 mlx5_rescan_drivers_locked+0xbc/0x2a0 [mlx5_core] [...] Do not directly remove psp from the _mlx5e_remove path, the PSP cleanup happens as part of profile cleanup.

Affected products

Linux kernel: 6.18 — fixed in 6.19

How to fix

Upgrade to a fixed version: Linux kernel 6.19. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2025-68779 or the next vulnerability affects your stack