Description

In the Linux kernel, the following vulnerability has been resolved: drm/xe/guc: Add devm release action to safely tear down CT When a buffer object (BO) is allocated with the XE_BO_FLAG_GGTT_INVALIDATE flag, the driver initiates TLB invalidation requests via the CTB mechanism while releasing the BO. However a premature release of the CTB BO can lead to system crashes, as observed in: Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:h2g_write+0x2f3/0x7c0 [xe] Call Trace: guc_ct_send_locked+0x8b/0x670 [xe] xe_guc_ct_send_locked+0x19/0x60 [xe] send_tlb_invalidation+0xb4/0x460 [xe] xe_gt_tlb_invalidation_ggtt+0x15e/0x2e0 [xe] ggtt_invalidate_gt_tlb.part.0+0x16/0x90 [xe] ggtt_node_remove+0x110/0x140 [xe] xe_ggtt_node_remove+0x40/0xa0 [xe] xe_ggtt_remove_bo+0x87/0x250 [xe] Introduce a devm-managed release action during xe_guc_ct_init() and xe_guc_ct_init_post_hwconfig() to ensure proper CTB disablement before resource deallocation, preventing the use-after-free scenario.

References 2

• git.kernel.org https://git.kernel.org/stable/c/52faa05fcd9f78af99abebe30a4b7b444744c991
• git.kernel.org https://git.kernel.org/stable/c/ee4b32220a6b41e71512e8804585325e685456ba

Remediation