[PATCH v4 29/31] accel: ethosu: Ensure cmd stream is multiple of 4 bytes

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

The command-stream validator consumes 32-bit words, so reject empty or
unaligned streams at that boundary. This also prevents QSIZE from
receiving an unvalidated trailing byte.

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_gem.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/accel/ethosu/ethosu_gem.c b/drivers/accel/ethosu/ethosu_gem.c
index 0b227664afc7..1935440fb815 100644
--- a/drivers/accel/ethosu/ethosu_gem.c
+++ b/drivers/accel/ethosu/ethosu_gem.c
@@ -965,6 +965,8 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 
 	if (!info)
 		return -ENOMEM;
+	if (!size || size & 3)
+		return -EINVAL;
 	info->cmd_size = size;
 
 	cmd_state_init(&st);

-- 
2.53.0