SB20261022411 - NULL pointer dereference in Linux kernel broadcom genet driver

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-98798)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to cause a denial of service by leaving networking unresponsive until a reboot.

The vulnerability exists due to a null pointer dereference in the Linux kernel bcmgenet driver's receive coalescing handling when setting receive coalescing parameters on an interface that has never been opened. A local privileged user can run a command such as "ethtool -C eth0 rx-usecs 50" to dereference an uninitialized receive ring private pointer and trigger a kernel fault while the RTNL lock is held, leaving networking stuck.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0d867b91598b6ed2f75998c34f4e2869631da31e
• https://git.kernel.org/stable/c/19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1
• https://git.kernel.org/stable/c/213ff02ab26a4543ef02b4db393bbdd5fa5679a7
• https://git.kernel.org/stable/c/2294b62eaec6fd3c76a261d287f66641eeafd5f0
• https://git.kernel.org/stable/c/d870102b5425390cab42eebbf3d19ec6a43c6734