From 967feea5ebb744dce97ab327d33502b43fca0c7f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 12 Mar 2017 03:04:06 +0100 Subject: [PATCH] avcodec/vp6: clear dimensions on failed resolution change in vp6_parse_header() Fixes: 807/clusterfuzz-testcase-6470061042696192 Fixes null pointer dereference Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/vp6.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/libavcodec/vp6.c b/libavcodec/vp6.c index f0e60a3822..4afd67b3a4 100644 --- a/libavcodec/vp6.c +++ b/libavcodec/vp6.c @@ -108,7 +108,7 @@ static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size) ret = ff_vp56_init_range_decoder(c, buf+6, buf_size-6); if (ret < 0) - return ret; + goto fail; vp56_rac_gets(c, 2); parse_filter_info = s->filter_header; @@ -162,9 +162,8 @@ static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size) buf += coeff_offset; buf_size -= coeff_offset; if (buf_size < 0) { - if (s->frames[VP56_FRAME_CURRENT]->key_frame) - ff_set_dimensions(s->avctx, 0, 0); - return AVERROR_INVALIDDATA; + ret = AVERROR_INVALIDDATA; + goto fail; } if (s->use_huffman) { s->parse_coeff = vp6_parse_coeff_huffman; @@ -172,7 +171,7 @@ static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size) } else { ret = ff_vp56_init_range_decoder(&s->cc, buf, buf_size); if (ret < 0) - return ret; + goto fail; s->ccp = &s->cc; } } else { @@ -180,6 +179,10 @@ static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size) } return res; +fail: + if (res == VP56_SIZE_CHANGE) + ff_set_dimensions(s->avctx, 0, 0); + return ret; } static void vp6_coeff_order_table_init(VP56Context *s)