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drm/mediatek: Fix coverity issue with unintentional integer overflow

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[ Upstream commit b0b0d811eac6b4c52cb9ad632fa6384cf48869e7 ]

1. Instead of multiplying 2 variable of different types. Change to
assign a value of one variable and then multiply the other variable.

2. Add a int variable for multiplier calculation instead of calculating
different types multiplier with dma_addr_t variable directly.

Fixes: 1a64a7aff8da ("drm/mediatek: Fix cursor plane no update")
Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230907091425.9526-1-jason-jh.lin@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jason-JH.Lin 2023-09-07 17:14:25 +08:00 committed by Greg Kroah-Hartman
parent 7684d956d7
commit 96312a251d
2 changed files with 38 additions and 10 deletions
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9
drivers/gpu/drm/mediatek/mtk_drm_gem.c
View File

@ -121,7 +121,14 @@ int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
int ret;
args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
args->size = args->pitch * args->height;
/*
* Multiply 2 variables of different types,
* for example: args->size = args->spacing * args->height;
* may cause coverity issue with unintentional overflow.
*/
args->size = args->pitch;
args->size *= args->height;
mtk_gem = mtk_drm_gem_create(dev, args->size, false);
if (IS_ERR(mtk_gem))

39
drivers/gpu/drm/mediatek/mtk_drm_plane.c
View File

@ -141,6 +141,7 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
dma_addr_t addr;
dma_addr_t hdr_addr = 0;
unsigned int hdr_pitch = 0;
int offset;
gem = fb->obj[0];
mtk_gem = to_mtk_gem_obj(gem);
@ -150,8 +151,15 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
modifier = fb->modifier;
if (modifier == DRM_FORMAT_MOD_LINEAR) {
addr += (new_state->src.x1 >> 16) * fb->format->cpp[0];
addr += (new_state->src.y1 >> 16) * pitch;
/*
* Using dma_addr_t variable to calculate with multiplier of different types,
* for example: addr += (new_state->src.x1 >> 16) * fb->format->cpp[0];
* may cause coverity issue with unintentional overflow.
*/
offset = (new_state->src.x1 >> 16) * fb->format->cpp[0];
addr += offset;
offset = (new_state->src.y1 >> 16) * pitch;
addr += offset;
} else {
int width_in_blocks = ALIGN(fb->width, AFBC_DATA_BLOCK_WIDTH)
/ AFBC_DATA_BLOCK_WIDTH;
@ -159,21 +167,34 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
/ AFBC_DATA_BLOCK_HEIGHT;
int x_offset_in_blocks = (new_state->src.x1 >> 16) / AFBC_DATA_BLOCK_WIDTH;
int y_offset_in_blocks = (new_state->src.y1 >> 16) / AFBC_DATA_BLOCK_HEIGHT;
int hdr_size;
int hdr_size, hdr_offset;
hdr_pitch = width_in_blocks * AFBC_HEADER_BLOCK_SIZE;
pitch = width_in_blocks * AFBC_DATA_BLOCK_WIDTH *
AFBC_DATA_BLOCK_HEIGHT * fb->format->cpp[0];
hdr_size = ALIGN(hdr_pitch * height_in_blocks, AFBC_HEADER_ALIGNMENT);
hdr_offset = hdr_pitch * y_offset_in_blocks +
AFBC_HEADER_BLOCK_SIZE * x_offset_in_blocks;
/*
* Using dma_addr_t variable to calculate with multiplier of different types,
* for example: addr += hdr_pitch * y_offset_in_blocks;
* may cause coverity issue with unintentional overflow.
*/
hdr_addr = addr + hdr_offset;
hdr_addr = addr + hdr_pitch * y_offset_in_blocks +
AFBC_HEADER_BLOCK_SIZE * x_offset_in_blocks;
/* The data plane is offset by 1 additional block. */
addr = addr + hdr_size +
pitch * y_offset_in_blocks +
AFBC_DATA_BLOCK_WIDTH * AFBC_DATA_BLOCK_HEIGHT *
fb->format->cpp[0] * (x_offset_in_blocks + 1);
offset = pitch * y_offset_in_blocks +
AFBC_DATA_BLOCK_WIDTH * AFBC_DATA_BLOCK_HEIGHT *
fb->format->cpp[0] * (x_offset_in_blocks + 1);
/*
* Using dma_addr_t variable to calculate with multiplier of different types,
* for example: addr += pitch * y_offset_in_blocks;
* may cause coverity issue with unintentional overflow.
*/
addr = addr + hdr_size + offset;
}
mtk_plane_state->pending.enable = true;