Executive brief
A vulnerability in the Linux kernel's graphics driver for Snapdragon processors could cause the system to freeze or crash. This occurs when the system is low on memory and tries to reclaim resources, leading to a 'deadlock' where different parts of the system are waiting on each other indefinitely. This primarily impacts system availability and could lead to a denial of service.
Technical details
A circular locking dependency was identified in the MSM DRM driver (drivers/gpu/drm/msm) when running under memory pressure. The kswapd process, while holding the 'fs_reclaim' lock, attempts to acquire a reservation lock via the MSM shrinker (msm_gem_shrinker_scan). However, the reservation lock dependency chain already includes 'fs_reclaim', resulting in a deadlock. The fix replaces the blocking dma_resv_lock() call with dma_resv_trylock() within the shrinker path to avoid waiting on a lock that would trigger the circular dependency. This issue was specifically observed on Snapdragon X1 platforms.
Affected products
- Linux Linux Kernel 7.0.0-debug+
Timeline
- 2026-05-08: disclosed: Initial patch submitted by Daniel J Blueman
- 2026-05-15: patched: Patch committed to main tree by Rob Clark
- 2026-07-19: advisory: CVE-2026-64100 published