SB20260720253 - NULL pointer dereference in Linux kernel ethtool

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-63986)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/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 improper handling of an error pointer in net/ethtool/tsinfo.c when processing ethtool tsinfo dump requests. A local user can trigger the vulnerable code path to cause a denial of service.

The issue occurs because a failed prepare operation can leave no generic netlink message to cancel, leading to a kernel crash when an error pointer is passed to genlmsg_cancel().

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/2008f9bb1ede9b688624a241228b8e54fc74f0f6
• https://git.kernel.org/stable/c/c3fc9976f686f9a95baf87db9d387f218fd65394
• https://git.kernel.org/stable/c/d0d2c5ccd1de28368cebeef74d9c530a60eff9a5