From e248522d1b0d6dd8641f382cd5c4338d0ecd98e5 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 6 Feb 2017 11:17:10 +0100 Subject: [PATCH] avcodec/movtextdec: Fix decode_styl() cleanup Fixes: null pointer dereference Fixes: 555/clusterfuzz-testcase-5986646595993600 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/movtextdec.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/libavcodec/movtextdec.c b/libavcodec/movtextdec.c index 7b5b161561..81fd1d6deb 100644 --- a/libavcodec/movtextdec.c +++ b/libavcodec/movtextdec.c @@ -116,6 +116,8 @@ static void mov_text_cleanup(MovTextContext *m) av_freep(&m->s[i]); } av_freep(&m->s); + m->count_s = 0; + m->style_entries = 0; } } @@ -279,12 +281,14 @@ static int decode_hclr(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) static int decode_styl(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) { int i; - m->style_entries = AV_RB16(tsmb); + int style_entries = AV_RB16(tsmb); tsmb += 2; // A single style record is of length 12 bytes. - if (m->tracksize + m->size_var + 2 + m->style_entries * 12 > avpkt->size) + if (m->tracksize + m->size_var + 2 + style_entries * 12 > avpkt->size) return -1; + m->style_entries = style_entries; + m->box_flags |= STYL_BOX; for(i = 0; i < m->style_entries; i++) { m->s_temp = av_malloc(sizeof(*m->s_temp));