From e371f031b942d73e02c090170975561fabd5c264 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 23 Jan 2017 01:25:27 +0100 Subject: avcodec/pngdec: Fix off by 1 size in decode_zbuf() Fixes out of array access Fixes: 444/fuzz-2-ffmpeg_VIDEO_AV_CODEC_ID_PNG_fuzzer Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/pngdec.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'libavcodec/pngdec.c') diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c index 2f8d266c27..50a0a296b3 100644 --- a/libavcodec/pngdec.c +++ b/libavcodec/pngdec.c @@ -437,13 +437,13 @@ static int decode_zbuf(AVBPrint *bp, const uint8_t *data, av_bprint_init(bp, 0, -1); while (zstream.avail_in > 0) { - av_bprint_get_buffer(bp, 1, &buf, &buf_size); - if (!buf_size) { + av_bprint_get_buffer(bp, 2, &buf, &buf_size); + if (buf_size < 2) { ret = AVERROR(ENOMEM); goto fail; } zstream.next_out = buf; - zstream.avail_out = buf_size; + zstream.avail_out = buf_size - 1; ret = inflate(&zstream, Z_PARTIAL_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) { ret = AVERROR_EXTERNAL; -- cgit v1.2.3