CVE-2023-52738

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu/fence: Fix oops due to non-matching drm_sched init/fini

Currently amdgpu calls drm_sched_fini() from the fence driver sw fini

routine - such function is expected to be called only after the

respective init function - drm_sched_init() - was executed successfully.

Happens that we faced a driver probe failure in the Steam Deck

recently, and the function drm_sched_fini() was called even without

its counter-part had been previously called, causing the following oops:

amdgpu: probe of 0000:04:00.0 failed with error -110

BUG: kernel NULL pointer dereference, address: 0000000000000090

PGD 0 P4D 0

Oops: 0002 [#1] PREEMPT SMP NOPTI

CPU: 0 PID: 609 Comm: systemd-udevd Not tainted 6.2.0-rc3-gpiccoli #338

Hardware name: Valve Jupiter/Jupiter, BIOS F7A0113 11/04/2022

RIP: 0010:drm_sched_fini+0x84/0xa0 [gpu_sched]

[...]

Call Trace:

<TASK>

amdgpu_fence_driver_sw_fini+0xc8/0xd0 [amdgpu]

amdgpu_device_fini_sw+0x2b/0x3b

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References