[PATCH v4 22/31] accel: ethosu: Validate convolution parameter

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

The U65 NPU_OP_CONV command has no parameter fields, but the
validator interpreted bit zero as the U85 weights_ifm2 field. A crafted
U65 stream could consequently make validation skip the weight buffer
that hardware accesses.

Require a zero parameter on U65 and reject the reserved U85 parameter
bits.

Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
v2:
 - new patch
---
 drivers/accel/ethosu/ethosu_device.h | 1 +
 drivers/accel/ethosu/ethosu_gem.c    | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/accel/ethosu/ethosu_device.h b/drivers/accel/ethosu/ethosu_device.h
index 86412c152f4e..61dec8ec23ea 100644
--- a/drivers/accel/ethosu/ethosu_device.h
+++ b/drivers/accel/ethosu/ethosu_device.h
@@ -89,6 +89,7 @@ struct gen_pool;
 #define PMU_EV_TYPE_IDLE	0x20
 
 #define NPU_DMA_REGION_INDEX_MODE	BIT(11)
+#define NPU_OP_CONV_WEIGHTS_IFM2	BIT(0)
 
 #define NPU_CMD_CTRL_CMD1		BIT(14)
 
diff --git a/drivers/accel/ethosu/ethosu_gem.c b/drivers/accel/ethosu/ethosu_gem.c
index bf1489734769..143021a3f9ed 100644
--- a/drivers/accel/ethosu/ethosu_gem.c
+++ b/drivers/accel/ethosu/ethosu_gem.c
@@ -776,7 +776,10 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 				st.dma.dst.region, st.dma.dst.offset, dstlen);
 			break;
 		case NPU_OP_CONV:
-			use_ifm2 = param & 0x1;  // weights_ifm2
+			if ((ethosu_is_u65(edev) && param) || (param & ~NPU_OP_CONV_WEIGHTS_IFM2))
+				return -EINVAL;
+
+			use_ifm2 = param & NPU_OP_CONV_WEIGHTS_IFM2;
 			if (!cmd_state_reg_is_set(&st, NPU_SET_OFM_PRECISION))
 				return -EINVAL;
 			use_scale = !(st.ofm.precision & 0x100);

-- 
2.53.0