[FFmpeg-devel] avcodec/vp3: Check eob_run

Submitted by Michael Niedermayer on Feb. 9, 2018, 3:41 a.m.

Details

Message ID 20180209034144.21288-1-michael@niedermayer.cc
State New
Headers show

Commit Message

Michael Niedermayer Feb. 9, 2018, 3:41 a.m.
Fixes: out of array access
Fixes: 5919/clusterfuzz-testcase-minimized-5859311382167552

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/vp3.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Paul B Mahol Feb. 9, 2018, 8:23 a.m.
On 2/9/18, Michael Niedermayer <michael@niedermayer.cc> wrote:
> Fixes: out of array access
> Fixes: 5919/clusterfuzz-testcase-minimized-5859311382167552
>
> Found-by: continuous fuzzing process
> https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/vp3.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
> index cf9c57f5fa..120c20f349 100644
> --- a/libavcodec/vp3.c
> +++ b/libavcodec/vp3.c
> @@ -978,6 +978,9 @@ static int unpack_vlcs(Vp3DecodeContext *s,
> GetBitContext *gb,
>              if (eob_run_get_bits[token])
>                  eob_run += get_bits(gb, eob_run_get_bits[token]);
>
> +            if (!eob_run)
> +                return AVERROR_INVALIDDATA;
> +
>              // record only the number of blocks ended in this plane,
>              // any spill will be recorded in the next plane.
>              if (eob_run > num_coeffs - coeff_i) {
> --
> 2.16.1
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>

probably ok
Michael Niedermayer Feb. 9, 2018, 12:48 p.m.
On Fri, Feb 09, 2018 at 04:41:44AM +0100, Michael Niedermayer wrote:
> Fixes: out of array access
> Fixes: 5919/clusterfuzz-testcase-minimized-5859311382167552
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/vp3.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
> index cf9c57f5fa..120c20f349 100644
> --- a/libavcodec/vp3.c
> +++ b/libavcodec/vp3.c
> @@ -978,6 +978,9 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
>              if (eob_run_get_bits[token])
>                  eob_run += get_bits(gb, eob_run_get_bits[token]);
>  
> +            if (!eob_run)
> +                return AVERROR_INVALIDDATA;
> +
>              // record only the number of blocks ended in this plane,
>              // any spill will be recorded in the next plane.
>              if (eob_run > num_coeffs - coeff_i) {

this is incorrect for theora, (its correct for vp3) i will post a better patch

[...]

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diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
index cf9c57f5fa..120c20f349 100644
--- a/libavcodec/vp3.c
+++ b/libavcodec/vp3.c
@@ -978,6 +978,9 @@  static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
             if (eob_run_get_bits[token])
                 eob_run += get_bits(gb, eob_run_get_bits[token]);
 
+            if (!eob_run)
+                return AVERROR_INVALIDDATA;
+
             // record only the number of blocks ended in this plane,
             // any spill will be recorded in the next plane.
             if (eob_run > num_coeffs - coeff_i) {