CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's Direct Rendering Manager (DRM) subsystem, specifically in the framebuffer helper where it improperly synchronizes output to the vertical blanking interval (vblank) of inactive CRTCs. This can lead to warnings and potential display issues, particularly in systems using multiple CRTCs. Linux system administrators and developers working with graphics drivers should prioritize this fix to ensure stable and reliable graphics performance.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: drm/fb-helper: Only consider active CRTCs for vblank sync Only synchronize fbdev output to the vblank of an active CRTC. Go over the list of CRTCs and pick the first that matches. Fixes warnings as the one shown below [ 77.201354] WARNING: drivers/gpu/drm/drm_vblank.c:1320 at drm_crtc_wait_one_vblank+0x194/0x1cc [drm], CPU#1: kworker/1:7/1867 [ 77.201354] omapdrm omapdrm.0: [drm] vblank wait timed out on crtc 0 This currently happens if the fbdev output is not on CRTC 0. Atomic and non-atomic drivers require distinct code paths. As for other fbdev operations, implement both and select the correct one at runtime. Not finding an active CRTC is not a bug. Do not wait in this case, but flush the display update as before. v4: - avoid possible deadlocks with locking context (Sashiko) v3: - drop excessive state validation (Jani) - acquire plane and CRTC mutices (Sashiko) v2: - move look-up code into separate helper - support drivers with legacy modesetting v1: - see https://lore.kernel.org/dri-devel/1c9e0e24-9c4a-4259-8700-cf9e5fd60ca3@suse.de/