From: Shuicheng Lin Date: Thu, 9 Apr 2026 00:34:49 +0000 (+0000) Subject: drm/xe: Fix potential NULL deref in xe_exec_queue_tlb_inval_last_fence_put_unlocked X-Git-Tag: v7.1-rc2~7^2^2~10 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f8c4151d50b12923b67819ebf03c1c6782c984c1;p=thirdparty%2Fkernel%2Flinux.git drm/xe: Fix potential NULL deref in xe_exec_queue_tlb_inval_last_fence_put_unlocked xe_exec_queue_tlb_inval_last_fence_put_unlocked() uses q->vm->xe as the first argument to xe_assert(). This function is called unconditionally from xe_exec_queue_destroy() for all queues, including kernel queues that have q->vm == NULL (e.g., queues created during GT init in xe_gt_record_default_lrcs() with vm=NULL). While current compilers optimize away the q->vm->xe dereference (even in CONFIG_DRM_XE_DEBUG=y builds, the compiler pushes the dereference into the WARN branch that is only taken when the assert condition is false), the code is semantically incorrect and constitutes undefined behavior in the C abstract machine for the NULL pointer case. Use gt_to_xe(q->gt) instead, which is always valid for any exec queue. This is consistent with how xe_exec_queue_destroy() itself obtains the xe_device pointer in its own xe_assert at the top of the function. Fixes: b2d7ec41f2a3 ("drm/xe: Attach last fence to TLB invalidation job queues") Assisted-by: Claude:claude-opus-4.6 Reviewed-by: Matthew Brost Link: https://patch.msgid.link/20260409003449.3405767-1-shuicheng.lin@intel.com Signed-off-by: Shuicheng Lin (cherry picked from commit 96078a1c68bf97f17fd1d08c3f58f5c5cc9ccd65) Signed-off-by: Rodrigo Vivi --- diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c index b287d0e0e60a..8de8ec784a03 100644 --- a/drivers/gpu/drm/xe/xe_exec_queue.c +++ b/drivers/gpu/drm/xe/xe_exec_queue.c @@ -1760,7 +1760,7 @@ void xe_exec_queue_tlb_inval_last_fence_put(struct xe_exec_queue *q, void xe_exec_queue_tlb_inval_last_fence_put_unlocked(struct xe_exec_queue *q, unsigned int type) { - xe_assert(q->vm->xe, type == XE_EXEC_QUEUE_TLB_INVAL_MEDIA_GT || + xe_assert(gt_to_xe(q->gt), type == XE_EXEC_QUEUE_TLB_INVAL_MEDIA_GT || type == XE_EXEC_QUEUE_TLB_INVAL_PRIMARY_GT); dma_fence_put(q->tlb_inval[type].last_fence);