Commit 021f1b77 authored by Rob Herring (Arm)'s avatar Rob Herring (Arm)
Browse files

accel: ethosu: Handle possible underflow in IFM size calculations 



If the command stream has larger padding sizes than the IFM and OFM
diminsions, then the calculations will underflow to a negative value.
The result is a very large region bounds which is caught on submit, but
it's better to catch it earlier.

Current mesa ethosu driver has a signedness bug which resulted in
padding of 127 (the max) and triggers this issue.

Reviewed-and-Tested-by: default avatarAnders Roxell <anders.roxell@linaro.org>
Link: https://patch.msgid.link/20260218-ethos-fixes-v1-3-be3fa3ea9a30@kernel.org


Signed-off-by: default avatarRob Herring (Arm) <robh@kernel.org>
parent 838ae99f

drivers/accel/ethosu/ethosu_gem.c

+5 −2
Original line number Diff line number Diff line
@@ -245,11 +245,14 @@ static int calc_sizes(struct drm_device *ddev, 
			((st->ifm.stride_kernel >> 1) & 0x1) + 1;

		u32 stride_x = ((st->ifm.stride_kernel >> 5) & 0x2) +

			(st->ifm.stride_kernel & 0x1) + 1;

		u32 ifm_height = st->ofm.height[2] * stride_y +

		s32 ifm_height = st->ofm.height[2] * stride_y +

			st->ifm.height[2] - (st->ifm.pad_top + st->ifm.pad_bottom);

		u32 ifm_width  = st->ofm.width * stride_x +

		s32 ifm_width = st->ofm.width * stride_x +

			st->ifm.width - (st->ifm.pad_left + st->ifm.pad_right);



		if (ifm_height < 0 || ifm_width < 0)

			return -EINVAL;



		len = feat_matrix_length(info, &st->ifm, ifm_width,

					 ifm_height, st->ifm.depth);

		dev_dbg(ddev->dev, "op %d: IFM:%d:0x%llx-0x%llx\n",