[FFmpeg-cvslog] avcodec/smacker: Check space before decoding type

Michael Niedermayer git at videolan.org
Fri Apr 24 02:13:23 EEST 2020


ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Wed Jan  1 20:43:05 2020 +0100| [d641368fc29ceaf405a112d9d6608b21875ab7ad] | committer: Michael Niedermayer

avcodec/smacker: Check space before decoding type

Fixes: Timeout (232sec -> 280ms)
Fixes: 19682/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SMACKER_fuzzer-5654129649385472

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 6f5c18da5977a3214e1ea30e6b0c0d9d858ce83d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d641368fc29ceaf405a112d9d6608b21875ab7ad
---

 libavcodec/smacker.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/smacker.c b/libavcodec/smacker.c
index dafef82c6a..6abc39ec35 100644
--- a/libavcodec/smacker.c
+++ b/libavcodec/smacker.c
@@ -386,6 +386,8 @@ static av_always_inline int smk_get_code(GetBitContext *gb, int *recode, int *la
     int v;
 
     while(*table & SMK_NODE) {
+        if (get_bits_left(gb) < 1)
+            return AVERROR_INVALIDDATA;
         if(get_bits1(gb))
             table += (*table) & (~SMK_NODE);
         table++;
@@ -450,6 +452,8 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
         uint16_t pix;
 
         type = smk_get_code(&gb, smk->type_tbl, smk->type_last);
+        if (type < 0)
+            return type;
         run = block_runs[(type >> 2) & 0x3F];
         switch(type & 3){
         case SMK_BLK_MONO:



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