In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix NULL pointer dereference in amdgpu_dm_crtc_set_vblank()
amdgpu_dm_crtc_set_vblank() dereferences acrtc_state->stream when
vblank is enabled/queried from DRM_IOCTL_MODE_CRTC_GET_SEQUENCE before
a stream is attached to it.
BUG: kernel NULL pointer dereference, address: 0000000000000008
RIP: amdgpu_dm_crtc_set_vblank+0x6b/0x4d0 [amdgpu]
Call Trace:
drm_vblank_enable
drm_vblank_get
drm_crtc_get_sequence_ioctl
drm_ioctl_kernel
drm_ioctl
Reproduced by running VKCTS with WSI tests enabled on RADV.
Guard the enable path on acrtc_state->stream being non-NULL, matching
the existing checks in this function.
(cherry picked from commit 7b1b31bf6942e6f43509b48da23f8e27269aac39)