| From 27a99e2c7d450fef15594671eef4465c8a166bd7 Mon Sep 17 00:00:00 2001 |
| From: Michael Niedermayer <michael@niedermayer.cc> |
| Date: Wed, 28 Oct 2020 20:11:54 +0100 |
| Subject: [PATCH] avformat/vividas: improve extradata packing checks in |
| track_header() |
| |
| Fixes: out of array accesses |
| Fixes: 26622/clusterfuzz-testcase-minimized-ffmpeg_dem_VIVIDAS_fuzzer-6581200338288640 |
| |
| Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg |
| Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> |
| |
| Upstream-Status: Backport [https://github.com/FFmpeg/FFmpeg/commit/27a99e2c7d450fef15594671eef4465c8a166bd7] |
| |
| CVE: CVE-2020-35964 |
| |
| Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> |
| Signed-off-by: Khairul Rohaizzat Jamaluddin <khairul.rohaizzat.jamaluddin@intel.com> |
| --- |
| libavformat/vividas.c | 12 ++++++------ |
| 1 file changed, 6 insertions(+), 6 deletions(-) |
| |
| diff --git a/libavformat/vividas.c b/libavformat/vividas.c |
| index 83d0ed116787..46c66bf9a0ae 100644 |
| --- a/libavformat/vividas.c |
| +++ b/libavformat/vividas.c |
| @@ -28,6 +28,7 @@ |
| * @sa http://wiki.multimedia.cx/index.php?title=Vividas_VIV |
| */ |
| |
| +#include "libavutil/avassert.h" |
| #include "libavutil/intreadwrite.h" |
| #include "avio_internal.h" |
| #include "avformat.h" |
| @@ -379,7 +380,7 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s, uint8_t * |
| |
| if (avio_tell(pb) < off) { |
| int num_data; |
| - int xd_size = 0; |
| + int xd_size = 1; |
| int data_len[256]; |
| int offset = 1; |
| uint8_t *p; |
| @@ -393,10 +394,10 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s, uint8_t * |
| return AVERROR_INVALIDDATA; |
| } |
| data_len[j] = len; |
| - xd_size += len; |
| + xd_size += len + 1 + len/255; |
| } |
| |
| - ret = ff_alloc_extradata(st->codecpar, 64 + xd_size + xd_size / 255); |
| + ret = ff_alloc_extradata(st->codecpar, xd_size); |
| if (ret < 0) |
| return ret; |
| |
| @@ -405,9 +406,7 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s, uint8_t * |
| |
| for (j = 0; j < num_data - 1; j++) { |
| unsigned delta = av_xiphlacing(&p[offset], data_len[j]); |
| - if (delta > data_len[j]) { |
| - return AVERROR_INVALIDDATA; |
| - } |
| + av_assert0(delta <= xd_size - offset); |
| offset += delta; |
| } |
| |
| @@ -418,6 +417,7 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s, uint8_t * |
| av_freep(&st->codecpar->extradata); |
| break; |
| } |
| + av_assert0(data_len[j] <= xd_size - offset); |
| offset += data_len[j]; |
| } |
| |