[FFmpeg-devel,3/3] avcodec/truemotion2: Check huffman code max bits

Submitted by Michael Niedermayer on Nov. 17, 2018, 2:01 a.m.

Details

Message ID 20181117020145.17164-3-michael@niedermayer.cc
State Accepted
Headers show

Commit Message

Michael Niedermayer Nov. 17, 2018, 2:01 a.m.
Fixes: Timeout
Fixes: 10984/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TRUEMOTION2_fuzzer-6643310750859264

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/truemotion2.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

Comments

Tomas Härdin Nov. 18, 2018, 10:29 p.m.
lör 2018-11-17 klockan 03:01 +0100 skrev Michael Niedermayer:
> Fixes: Timeout
> Fixes: 10984/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TRUEMOTION2_fuzzer-6643310750859264
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/truemotion2.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/libavcodec/truemotion2.c b/libavcodec/truemotion2.c
> index c583ff4032..5d12a70839 100644
> --- a/libavcodec/truemotion2.c
> +++ b/libavcodec/truemotion2.c
> @@ -114,7 +114,7 @@ typedef struct TM2Huff {
>  
>  static int tm2_read_tree(TM2Context *ctx, uint32_t prefix, int length, TM2Huff *huff)

Since you seem to be changing what this function returns, a comment
saying what it returns would be nice

Don't have much else to say about the patch since I don't know this
format

/Tomas
Michael Niedermayer Nov. 19, 2018, 1:02 a.m.
On Sun, Nov 18, 2018 at 11:29:10PM +0100, Tomas Härdin wrote:
> lör 2018-11-17 klockan 03:01 +0100 skrev Michael Niedermayer:
> > Fixes: Timeout
> > Fixes: 10984/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TRUEMOTION2_fuzzer-6643310750859264
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> > ---
> >  libavcodec/truemotion2.c | 15 ++++++++++-----
> >  1 file changed, 10 insertions(+), 5 deletions(-)
> > 
> > diff --git a/libavcodec/truemotion2.c b/libavcodec/truemotion2.c
> > index c583ff4032..5d12a70839 100644
> > --- a/libavcodec/truemotion2.c
> > +++ b/libavcodec/truemotion2.c
> > @@ -114,7 +114,7 @@ typedef struct TM2Huff {
> >  
> >  static int tm2_read_tree(TM2Context *ctx, uint32_t prefix, int length, TM2Huff *huff)
> 
> Since you seem to be changing what this function returns, a comment
> saying what it returns would be nice

will document this better

thanks 

[...]

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diff --git a/libavcodec/truemotion2.c b/libavcodec/truemotion2.c
index c583ff4032..5d12a70839 100644
--- a/libavcodec/truemotion2.c
+++ b/libavcodec/truemotion2.c
@@ -114,7 +114,7 @@  typedef struct TM2Huff {
 
 static int tm2_read_tree(TM2Context *ctx, uint32_t prefix, int length, TM2Huff *huff)
 {
-    int ret;
+    int ret, ret2;
     if (length > huff->max_bits) {
         av_log(ctx->avctx, AV_LOG_ERROR, "Tree exceeded its given depth (%i)\n",
                huff->max_bits);
@@ -133,14 +133,14 @@  static int tm2_read_tree(TM2Context *ctx, uint32_t prefix, int length, TM2Huff *
         huff->bits[huff->num] = prefix;
         huff->lens[huff->num] = length;
         huff->num++;
-        return 0;
+        return length;
     } else { /* non-terminal node */
-        if ((ret = tm2_read_tree(ctx, prefix << 1, length + 1, huff)) < 0)
-            return ret;
+        if ((ret2 = tm2_read_tree(ctx, prefix << 1, length + 1, huff)) < 0)
+            return ret2;
         if ((ret = tm2_read_tree(ctx, (prefix << 1) | 1, length + 1, huff)) < 0)
             return ret;
     }
-    return 0;
+    return FFMAX(ret, ret2);
 }
 
 static int tm2_build_huff_table(TM2Context *ctx, TM2Codes *code)
@@ -183,6 +183,11 @@  static int tm2_build_huff_table(TM2Context *ctx, TM2Codes *code)
 
     res = tm2_read_tree(ctx, 0, 0, &huff);
 
+    if (res >= 0 && res != huff.max_bits) {
+        av_log(ctx->avctx, AV_LOG_ERROR, "Got less bits than expected: %i of %i\n",
+               res, huff.max_bits);
+        res = AVERROR_INVALIDDATA;
+    }
     if (huff.num != huff.max_num) {
         av_log(ctx->avctx, AV_LOG_ERROR, "Got less codes than expected: %i of %i\n",
                huff.num, huff.max_num);