From 745c40a47f885e57ad97a775bbaa5c9973430276 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 17 Dec 2013 02:32:19 +0100 Subject: [PATCH] avcodec/gifdec: check that the correct number of bytes was decoded Fixes use of uninitialized memory Fixes: msan_uninit-mem_7f084c646637_9261_top_title_green_frog.gif Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libavcodec/gifdec.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libavcodec/gifdec.c b/libavcodec/gifdec.c index c7b9ac8726..78c8900628 100644 --- a/libavcodec/gifdec.c +++ b/libavcodec/gifdec.c @@ -237,8 +237,12 @@ static int gif_read_image(GifState *s, AVFrame *frame) pass = 0; y1 = 0; for (y = 0; y < height; y++) { - if (ff_lzw_decode(s->lzw, s->idx_line, width) == 0) + int count = ff_lzw_decode(s->lzw, s->idx_line, width); + if (count != width) { + if (count) + av_log(s->avctx, AV_LOG_ERROR, "LZW decode failed\n"); goto decode_tail; + } pr = ptr + width;