SB20261022396 - NULL pointer dereference in Linux kernel display amdgpu_dm driver

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-98786)

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 through a kernel NULL pointer dereference.

The vulnerability exists due to unchecked NULL pointer dereferences in the AMD display driver's dm_dp_mst_is_port_support_mode() and get_conv_frl_bw() functions when mode validation races with DisplayPort multi-stream transport (MST) unplug handling. A local user can trigger overlapping mode validation and MST unplug processing to potentially crash the kernel when either function accesses an asynchronously cleared dc_sink pointer.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/217f64f348c90cba62164e7ff38e0ccf78a5ca09
• https://git.kernel.org/stable/c/daa0437fe5e451856aaf8fda602a9fc2105bbd54