Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider: - [High] accel: ethosu: off-by-one in OFM block size for resize_axis_size() - [High] accel: ethosu: off-by-one IFM coordinate bound in resize_axis_size() --
commit 97ac650ca88e247fea2055f1c004d98774087255 Author: Rob Herring (Arm) <[email protected]> accel: ethosu: Validate resize operations This commit adds command stream validation for Ethos-U85 NPU_OP_RESIZE operations by tracking the resize scale, offset, step, and OFM block size registers and validating the input feature map bounds. > diff --git a/drivers/accel/ethosu/ethosu_gem.c > b/drivers/accel/ethosu/ethosu_gem.c > index fe6bf1a2f8cb2..0b227664afc7b 100644 > --- a/drivers/accel/ethosu/ethosu_gem.c > +++ b/drivers/accel/ethosu/ethosu_gem.c [ ... ] > @@ -663,6 +675,98 @@ calc_acc_input_size(struct drm_device *ddev, > return ret; > } > > +static int resize_axis_size(struct cmd_state *st, int axis, u16 ofm_size, > + u16 ofm_blk_size, u32 *size) > +{ > + struct resize_axis *resize = &st->resize[axis]; > + u64 one_step, blk_step, coord; > + > + if (resize->offset < -(s16)resize->scale_n || > + resize->offset >= resize->scale_n || > + resize->one_step_mod >= resize->scale_n || > + resize->blk_step_mod >= resize->scale_n) > + return -EINVAL; > + > + one_step = resize->one_step_int * resize->scale_n + > + resize->one_step_mod; > + blk_step = resize->blk_step_int * resize->scale_n + > + resize->blk_step_mod; > + if (check_mul_overflow((u64)ofm_blk_size, one_step, &coord) || > + blk_step != coord) > + return -EINVAL; > + > + if (check_mul_overflow((u64)ofm_size, one_step, &coord) || > + check_add_overflow(coord, (u64)resize->scale_n - 1, &coord)) > + return -EINVAL; > + > + coord = div_u64(coord, resize->scale_n); > + if (coord >= U32_MAX) > + return -EINVAL; > + > + *size = coord + 1; > + return 0; > +} > + > + > +static int calc_sizes_resize(struct drm_device *ddev, > + struct ethosu_validated_cmdstream_info *info, > + struct cmd_state *st) > +{ > + struct ethosu_device *edev = to_ethosu_device(ddev); > + u32 ifm_width, ifm_height; > + u64 len; > + int ret; > + > + if (!cmd_state_reg_is_set(st, NPU_SET_KERNEL_WIDTH_M1) || > + !cmd_state_reg_is_set(st, NPU_SET_KERNEL_HEIGHT_M1) || > + !cmd_state_reg_is_set(st, NPU_SET_OFM_BLK_WIDTH_M1) || > + !cmd_state_reg_is_set(st, NPU_SET_OFM_BLK_HEIGHT_M1) || > + !cmd_state_reg_is_set(st, NPU_SET_RESIZE_X_SCALE_N_M1) || > + !cmd_state_reg_is_set(st, NPU_SET_RESIZE_Y_SCALE_N_M1) || > + !cmd_state_reg_is_set(st, NPU_SET_RESIZE_X_OFFSET) || > + !cmd_state_reg_is_set(st, NPU_SET_RESIZE_Y_OFFSET) || > + !cmd_state_reg_is_set(st, NPU_SET_RESIZE_X) || > + !cmd_state_reg_is_set(st, NPU_SET_RESIZE_Y)) > + return -EINVAL; > + > + ret = resize_axis_size(st, 0, st->ofm.width, st->ofm_blk_width, > + &ifm_width); > + if (ret) > + return ret; > + ret = resize_axis_size(st, 1, st->ofm.height[2], st->ofm_blk_height, > + &ifm_height); > + if (ret) > + return ret; > + > + if (check_add_overflow(ifm_width, (u32)st->ifm.width, &ifm_width) || > + check_add_overflow(ifm_height, (u32)st->ifm.height[2], &ifm_height)) > + return -EINVAL; > + > + ret = feat_matrix_size(edev, info, st, &st->ifm, FEAT_MATRIX_IFM, > + ifm_width, ifm_height, st->ifm.depth, false, > &len); [Severity: High] Does this overestimate ifm_width and ifm_height when passing them to feat_matrix_size()? In resize_axis_size(), ofm_size is already the 0-based maximum OFM coordinate (st->ofm.width or st->ofm.height[2]), so coord after dividing by resize->scale_n is a 0-based IFM coordinate. Setting *size = coord + 1 converts it to a 1-based size, and calc_sizes_resize() then adds st->ifm.width (NPU_SET_KERNEL_WIDTH_M1) and st->ifm.height[2] (NPU_SET_KERNEL_HEIGHT_M1) on top of that. In addition, resize_axis_size() adds resize->scale_n - 1 rather than accounting for resize->offset, which can increase coord by another 1 when resize->offset < resize->scale_n - 1. However, feat_matrix_size() -> feat_matrix_check_location() -> feat_matrix_length() expects 0-based maximum coordinates (x, y, c), matching how st->ofm.width, st->ofm.height[2], and st->ifm.depth are passed: drivers/accel/ethosu/ethosu_gem.c:feat_matrix_length() { ... switch (storage) { case 0: if (x >= fm->width0 + 1) { x -= fm->width0 + 1; tile += 1; } if (y >= fm->height[tile] + 1) { y -= fm->height[tile] + 1; tile += 2; } break; ... } When ifm_width or ifm_height exceeds the actual 0-based maximum coordinate by 1 or 2 on a single-tile IFM (where fm->width0 and fm->height[0] are set to the IFM dimensions minus 1 and only NPU_SET_IFM_BASE0 is programmed), wouldn't feat_matrix_length() advance to tiles 1..3 and fail validation with -EINVAL, or require a larger IFM buffer than the tensor size? [ ... ] > @@ -1069,6 +1178,12 @@ static int > ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev, > } > st.ofm.precision = param; > break; > + case NPU_SET_OFM_BLK_WIDTH_M1: > + st.ofm_blk_width = param & 0x7f; > + break; > + case NPU_SET_OFM_BLK_HEIGHT_M1: > + st.ofm_blk_height = param & 0x7f; > + break; [Severity: High] Should st.ofm_blk_width and st.ofm_blk_height store (param & 0x7f) + 1 (or should resize_axis_size() add 1 to ofm_blk_size)? NPU_SET_OFM_BLK_WIDTH_M1 and NPU_SET_OFM_BLK_HEIGHT_M1 encode the block dimensions minus 1, similar to NPU_SET_RESIZE_X_SCALE_N_M1 and NPU_SET_RESIZE_Y_SCALE_N_M1 where param + 1 is stored. In ethosu_gem_cmdstream_copy_and_validate() -> calc_sizes_resize() -> resize_axis_size(), ofm_blk_size is multiplied directly by one_step: if (check_mul_overflow((u64)ofm_blk_size, one_step, &coord) || blk_step != coord) return -EINVAL; With the unadjusted _M1 value, resize_axis_size() checks that blk_step equals (block_size - 1) * one_step instead of block_size * one_step, which rejects valid NPU_OP_RESIZE command streams with -EINVAL whenever one_step is non-zero. -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=28
