Commit 40e846bb authored by Michael Niedermayer's avatar Michael Niedermayer
Browse files

avcodec/gif: Fix lzw buffer size


Fixes out of array access
Fixes: aaa479088e6fb40b04837b3119f47b04/asan_heap-oob_e38c68_8576_9d653078b2470700e2834636f12ff557.tga

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: default avatarMichael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 03d83ba3

)
Signed-off-by: default avatarMichael Niedermayer <michael@niedermayer.cc>
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Showing with 5 additions and 2 deletions
+5 -2
......@@ -43,6 +43,7 @@ typedef struct GIFContext {
const AVClass *class;
LZWState *lzw;
uint8_t *buf;
int buf_size;
AVFrame *last_frame;
int flags;
uint32_t palette[AVPALETTE_COUNT]; ///< local reference palette for !pal8
......@@ -174,7 +175,7 @@ static int gif_image_write_image(AVCodecContext *avctx,
bytestream_put_byte(bytestream, 0x08);
ff_lzw_encode_init(s->lzw, s->buf, 2 * width * height,
ff_lzw_encode_init(s->lzw, s->buf, s->buf_size,
12, FF_LZW_GIF, put_bits);
ptr = buf + y_start*linesize + x_start;
......@@ -232,7 +233,8 @@ static av_cold int gif_encode_init(AVCodecContext *avctx)
s->transparent_index = -1;
s->lzw = av_mallocz(ff_lzw_encode_state_size);
s->buf = av_malloc(avctx->width*avctx->height*2);
s->buf_size = avctx->width*avctx->height*2 + 1000;
s->buf = av_malloc(s->buf_size);
s->tmpl = av_malloc(avctx->width);
if (!s->tmpl || !s->buf || !s->lzw)
return AVERROR(ENOMEM);
......@@ -324,6 +326,7 @@ static int gif_encode_close(AVCodecContext *avctx)
av_freep(&s->lzw);
av_freep(&s->buf);
s->buf_size = 0;
av_frame_free(&s->last_frame);
av_freep(&s->tmpl);
return 0;
......
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