| From 13c13109759090b7f7182480d075e13b36ed8edd Mon Sep 17 00:00:00 2001 |
| From: Paul B Mahol <onemda@gmail.com> |
| Date: Sat, 12 Nov 2022 15:19:21 +0100 |
| Subject: [PATCH] avcodec/smcenc: stop accessing out of bounds frame |
| |
| Upstream-Status: Backport [https://github.com/FFmpeg/FFmpeg/commit/13c13109759090b7f7182480d075e13b36ed8edd] |
| |
| Signed-off-by: <narpat.mali@windriver.com> |
| |
| --- |
| libavcodec/smcenc.c | 18 ++++++++++++++---- |
| 1 file changed, 14 insertions(+), 4 deletions(-) |
| |
| diff --git a/libavcodec/smcenc.c b/libavcodec/smcenc.c |
| index f3d26a4e8d..33549b8ab4 100644 |
| --- a/libavcodec/smcenc.c |
| +++ b/libavcodec/smcenc.c |
| @@ -61,6 +61,7 @@ typedef struct SMCContext { |
| { \ |
| row_ptr += stride * 4; \ |
| pixel_ptr = row_ptr; \ |
| + cur_y += 4; \ |
| } \ |
| } \ |
| } |
| @@ -117,6 +118,7 @@ static void smc_encode_stream(SMCContext *s, const AVFrame *frame, |
| const uint8_t *prev_pixels = (const uint8_t *)s->prev_frame->data[0]; |
| uint8_t *distinct_values = s->distinct_values; |
| const uint8_t *pixel_ptr, *row_ptr; |
| + const int height = frame->height; |
| const int width = frame->width; |
| uint8_t block_values[16]; |
| int block_counter = 0; |
| @@ -125,13 +127,14 @@ static void smc_encode_stream(SMCContext *s, const AVFrame *frame, |
| int color_octet_index = 0; |
| int color_table_index; /* indexes to color pair, quad, or octet tables */ |
| int total_blocks; |
| + int cur_y = 0; |
| |
| memset(s->color_pairs, 0, sizeof(s->color_pairs)); |
| memset(s->color_quads, 0, sizeof(s->color_quads)); |
| memset(s->color_octets, 0, sizeof(s->color_octets)); |
| |
| /* Number of 4x4 blocks in frame. */ |
| - total_blocks = ((frame->width + 3) / 4) * ((frame->height + 3) / 4); |
| + total_blocks = ((width + 3) / 4) * ((height + 3) / 4); |
| |
| pixel_ptr = row_ptr = src_pixels; |
| |
| @@ -145,11 +148,13 @@ static void smc_encode_stream(SMCContext *s, const AVFrame *frame, |
| int cache_index; |
| int distinct = 0; |
| int blocks = 0; |
| + int frame_y = cur_y; |
| |
| while (prev_pixels && s->key_frame == 0 && block_counter + inter_skip_blocks < total_blocks) { |
| + const int y_size = FFMIN(4, height - cur_y); |
| int compare = 0; |
| |
| - for (int y = 0; y < 4; y++) { |
| + for (int y = 0; y < y_size; y++) { |
| const ptrdiff_t offset = pixel_ptr - src_pixels; |
| const uint8_t *prev_pixel_ptr = prev_pixels + offset; |
| |
| @@ -170,8 +175,10 @@ static void smc_encode_stream(SMCContext *s, const AVFrame *frame, |
| |
| pixel_ptr = xpixel_ptr; |
| row_ptr = xrow_ptr; |
| + cur_y = frame_y; |
| |
| while (block_counter > 0 && block_counter + intra_skip_blocks < total_blocks) { |
| + const int y_size = FFMIN(4, height - cur_y); |
| const ptrdiff_t offset = pixel_ptr - src_pixels; |
| const int sy = offset / stride; |
| const int sx = offset % stride; |
| @@ -180,7 +187,7 @@ static void smc_encode_stream(SMCContext *s, const AVFrame *frame, |
| const uint8_t *old_pixel_ptr = src_pixels + nx + ny * stride; |
| int compare = 0; |
| |
| - for (int y = 0; y < 4; y++) { |
| + for (int y = 0; y < y_size; y++) { |
| compare |= memcmp(old_pixel_ptr + y * stride, pixel_ptr + y * stride, 4); |
| if (compare) |
| break; |
| @@ -197,9 +204,11 @@ static void smc_encode_stream(SMCContext *s, const AVFrame *frame, |
| |
| pixel_ptr = xpixel_ptr; |
| row_ptr = xrow_ptr; |
| + cur_y = frame_y; |
| |
| while (block_counter + coded_blocks < total_blocks && coded_blocks < 256) { |
| - for (int y = 0; y < 4; y++) |
| + const int y_size = FFMIN(4, height - cur_y); |
| + for (int y = 0; y < y_size; y++) |
| memcpy(block_values + y * 4, pixel_ptr + y * stride, 4); |
| |
| qsort(block_values, 16, sizeof(block_values[0]), smc_cmp_values); |
| @@ -224,6 +233,7 @@ static void smc_encode_stream(SMCContext *s, const AVFrame *frame, |
| |
| pixel_ptr = xpixel_ptr; |
| row_ptr = xrow_ptr; |
| + cur_y = frame_y; |
| |
| blocks = coded_blocks; |
| distinct = coded_distinct; |
| -- |
| 2.34.1 |
| |