SB20260812400 - NULL pointer dereference in Linux kernel mlx5 core driver

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-68139)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a null pointer dereference in mlx5e_devcom_event_mpv in the Linux kernel mlx5 mlx5e multiport devcom handling when replaying affiliation events during PCI error recovery. A local user can trigger a crafted device recovery sequence to cause a denial of service.

The issue occurs because peer private data can become visible before the corresponding devcom backpointer is initialized, allowing a master-up event to reach a peer with a NULL devcom pointer.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/40f9a124ebbe0d60fe165fb3f87515c35b2d72f5
• https://git.kernel.org/stable/c/a60c81f168c9fe4f5d84302d1e32b717f5a8a933
• https://git.kernel.org/stable/c/c698b2735613f1f35c55688bd2252f75f31c49ad
• https://git.kernel.org/stable/c/e32649b4bad90a6216d8e93cd7dd050af8ac9740