[PATCH v4] drm/i915: Fix NULL pointer dereference in capture_engine

[Eugene Kobyak]

When the intel_context structure contains NULL,
it raises a NULL pointer dereference error in drm_info().

Fixes: e8a3319c31a1 ("drm/i915: Allow error capture without a request")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12309
Cc: John Harrison <John.C.Harrison at Intel.com>
Cc: <stable at vger.kernel.org> # v6.3+
Signed-off-by: Eugene Kobyak <eugene.kobyak at intel.com>
---
v2:
  - return drm_info to separate condition
v3:
  - create separate condition which generate string if intel_context exist
v4:
  - rollback and add check intel_context in log condition
 drivers/gpu/drm/i915/i915_gpu_error.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 135ded17334e..56f05a18870c 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1643,7 +1643,7 @@ capture_engine(struct intel_engine_cs *engine,
 		return NULL;
 
 	intel_engine_get_hung_entity(engine, &ce, &rq);
-	if (rq && !i915_request_started(rq))
+	if (rq && !i915_request_started(rq) && ce)
 		drm_info(&engine->gt->i915->drm, "Got hung context on %s with active request %lld:%lld [0x%04X] not yet started\n",
 			 engine->name, rq->fence.context, rq->fence.seqno, ce->guc_id.id);
 
-- 
2.34.1