[PATCH v4 12/31] accel: ethosu: Validate timeout command offset

["Rob Herring (Arm)" <robh@kernel.org>]

QREAD is supplied by the NPU. Check that its command-stream offset is
word aligned and within the validated command stream before using it to
index the command buffer in the timeout diagnostic.

Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
v4:
 - New patch
---
 drivers/accel/ethosu/ethosu_job.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/accel/ethosu/ethosu_job.c b/drivers/accel/ethosu/ethosu_job.c
index 3976115902e8..77218bb17006 100644
--- a/drivers/accel/ethosu/ethosu_job.c
+++ b/drivers/accel/ethosu/ethosu_job.c
@@ -345,6 +345,8 @@ static enum drm_gpu_sched_stat ethosu_job_timedout(struct drm_sched_job *bad)
 {
 	struct ethosu_job *job = to_ethosu_job(bad);
 	struct ethosu_device *dev = job->dev;
+	struct ethosu_validated_cmdstream_info *cmd_info =
+		to_ethosu_bo(job->cmd_bo)->info;
 	bool running;
 	int ret;
 	u32 *bocmds = to_drm_gem_dma_obj(job->cmd_bo)->vaddr;
@@ -367,9 +369,15 @@ static enum drm_gpu_sched_stat ethosu_job_timedout(struct drm_sched_job *bad)
 			return DRM_GPU_SCHED_STAT_NO_HANG;
 	}
 
-	dev_err(dev->base.dev, "NPU sched timed out: NPU %s, cmdstream offset 0x%x: 0x%x\n",
-		running ? "running" : "stopped",
-		cmdaddr, bocmds[cmdaddr / 4]);
+	if (!(cmdaddr & 3) && cmdaddr < cmd_info->cmd_size)
+		dev_err(dev->base.dev,
+			"NPU sched timed out: NPU %s, cmdstream offset 0x%x: 0x%x\n",
+			running ? "running" : "stopped", cmdaddr,
+			bocmds[cmdaddr / 4]);
+	else
+		dev_err(dev->base.dev,
+			"NPU sched timed out: NPU %s, invalid cmdstream offset 0x%x\n",
+			running ? "running" : "stopped", cmdaddr);
 
 	drm_sched_stop(&dev->sched, bad);
 

-- 
2.53.0