diff mbox series

[FFmpeg-devel,2/2] avcodec/h2645_parse: Check HEVC NAL size

Message ID 20220429221826.31666-2-michael@niedermayer.cc
State New
Headers show
Series [FFmpeg-devel,1/2] tools/target_dec_fuzzer: Adjust threshold or CFHD | expand

Checks

Context Check Description
yinshiyou/make_loongarch64 success Make finished
yinshiyou/make_fate_loongarch64 success Make fate finished
andriy/make_x86 success Make finished
andriy/make_fate_x86 success Make fate finished
andriy/make_armv7_RPi4 success Make finished
andriy/make_fate_armv7_RPi4 success Make fate finished

Commit Message

Michael Niedermayer April 29, 2022, 10:18 p.m. UTC
Fixes: Assertion failure
Fixes: 46662/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-4947860854013952

This also results in more frames to be decoded from fate samples

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/h2645_parse.c                               |  2 +-
 .../ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1  | 10 ++++++++++
 tests/ref/fate/hevc-conformance-RAP_B_Bossen_1         |  3 +++
 3 files changed, 14 insertions(+), 1 deletion(-)

Comments

Michael Niedermayer April 30, 2022, 9:35 a.m. UTC | #1
On Sat, Apr 30, 2022 at 12:18:26AM +0200, Michael Niedermayer wrote:

> Fixes: Assertion failure

it was this 
av_assert1((get_bits_count(gb) % 8) == 0);
that failed IIRC

[...]
Andreas Rheinhardt April 30, 2022, 8:45 p.m. UTC | #2
Michael Niedermayer:
> Fixes: Assertion failure
> Fixes: 46662/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-4947860854013952
> 
> This also results in more frames to be decoded from fate samples
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/h2645_parse.c                               |  2 +-
>  .../ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1  | 10 ++++++++++
>  tests/ref/fate/hevc-conformance-RAP_B_Bossen_1         |  3 +++
>  3 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c
> index 03780680c6..78ab22b76e 100644
> --- a/libavcodec/h2645_parse.c
> +++ b/libavcodec/h2645_parse.c
> @@ -292,7 +292,7 @@ static int hevc_parse_nal_header(H2645NAL *nal, void *logctx)
>  {
>      GetBitContext *gb = &nal->gb;
>  
> -    if (get_bits1(gb) != 0)
> +    if (get_bits_left(gb) < 16 || get_bits1(gb) != 0)
>          return AVERROR_INVALIDDATA;
>  
>      nal->type = get_bits(gb, 6);
> diff --git a/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1 b/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
> index 0c930f6556..3283925e38 100644
> --- a/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
> +++ b/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
> @@ -25,6 +25,16 @@
>  0,         19,         19,        1,   599040, 0x4227009b
>  0,         20,         20,        1,   599040, 0x1bda8be4
>  0,         21,         21,        1,   599040, 0xd1d5dcb4
> +0,         22,         22,        1,   599040, 0x58b2edb3
> +0,         23,         23,        1,   599040, 0xd1f795d8
> +0,         24,         24,        1,   599040, 0x3331d5e6
> +0,         25,         25,        1,   599040, 0x5e5ec2c9
> +0,         26,         26,        1,   599040, 0x3b907bf5
> +0,         27,         27,        1,   599040, 0xefcbf471
> +0,         28,         28,        1,   599040, 0x2769a578
> +0,         29,         29,        1,   599040, 0x812ce986
> +0,         30,         30,        1,   599040, 0xf07c212c
> +0,         31,         31,        1,   599040, 0xb5476890
>  0,         32,         32,        1,   599040, 0x00a0249f
>  0,         33,         33,        1,   599040, 0x7263f7cf
>  0,         34,         34,        1,   599040, 0x47054be4
> diff --git a/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1 b/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
> index e661ff245e..776267b59c 100644
> --- a/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
> +++ b/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
> @@ -70,6 +70,9 @@
>  0,         64,         64,        1,   149760, 0x3362678b
>  0,         65,         65,        1,   149760, 0x6e7fc851
>  0,         66,         66,        1,   149760, 0x33f96449
> +0,         67,         67,        1,   149760, 0xd9d05007
> +0,         75,         75,        1,   149760, 0x477f2cf2
> +0,         76,         76,        1,   149760, 0xe1f9ccd0
>  0,         77,         77,        1,   149760, 0xb3ba8cfb
>  0,         78,         78,        1,   149760, 0x64787995
>  0,         79,         79,        1,   149760, 0xc10de4c4

get_bit_length currently presumes every NALU to contain
rbsp_trailing_bits. Yet this is not true for the End of
Sequence/Bitstream units which are just headers without RBSP. For these
units, get_bit_length might truncate them -- it does so for end of
sequence units in H.264. It would not be a serious issue for H.265, as
the semantics of nuh_temporal_id_plus1 require nuh_temporal_id_plus1 to
be 1 for End of Sequence/Bitstream units. Nevertheless I think this
should be coupled with a patch that does not truncate the NAL unit if it
is just a header.

- Andreas
Andreas Rheinhardt June 22, 2022, 11:05 a.m. UTC | #3
Andreas Rheinhardt:
> Michael Niedermayer:
>> Fixes: Assertion failure
>> Fixes: 46662/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-4947860854013952
>>
>> This also results in more frames to be decoded from fate samples
>>
>> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
>> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
>> ---
>>  libavcodec/h2645_parse.c                               |  2 +-
>>  .../ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1  | 10 ++++++++++
>>  tests/ref/fate/hevc-conformance-RAP_B_Bossen_1         |  3 +++
>>  3 files changed, 14 insertions(+), 1 deletion(-)
>>
>> diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c
>> index 03780680c6..78ab22b76e 100644
>> --- a/libavcodec/h2645_parse.c
>> +++ b/libavcodec/h2645_parse.c
>> @@ -292,7 +292,7 @@ static int hevc_parse_nal_header(H2645NAL *nal, void *logctx)
>>  {
>>      GetBitContext *gb = &nal->gb;
>>  
>> -    if (get_bits1(gb) != 0)
>> +    if (get_bits_left(gb) < 16 || get_bits1(gb) != 0)
>>          return AVERROR_INVALIDDATA;
>>  
>>      nal->type = get_bits(gb, 6);
>> diff --git a/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1 b/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
>> index 0c930f6556..3283925e38 100644
>> --- a/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
>> +++ b/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
>> @@ -25,6 +25,16 @@
>>  0,         19,         19,        1,   599040, 0x4227009b
>>  0,         20,         20,        1,   599040, 0x1bda8be4
>>  0,         21,         21,        1,   599040, 0xd1d5dcb4
>> +0,         22,         22,        1,   599040, 0x58b2edb3
>> +0,         23,         23,        1,   599040, 0xd1f795d8
>> +0,         24,         24,        1,   599040, 0x3331d5e6
>> +0,         25,         25,        1,   599040, 0x5e5ec2c9
>> +0,         26,         26,        1,   599040, 0x3b907bf5
>> +0,         27,         27,        1,   599040, 0xefcbf471
>> +0,         28,         28,        1,   599040, 0x2769a578
>> +0,         29,         29,        1,   599040, 0x812ce986
>> +0,         30,         30,        1,   599040, 0xf07c212c
>> +0,         31,         31,        1,   599040, 0xb5476890
>>  0,         32,         32,        1,   599040, 0x00a0249f
>>  0,         33,         33,        1,   599040, 0x7263f7cf
>>  0,         34,         34,        1,   599040, 0x47054be4
>> diff --git a/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1 b/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
>> index e661ff245e..776267b59c 100644
>> --- a/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
>> +++ b/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
>> @@ -70,6 +70,9 @@
>>  0,         64,         64,        1,   149760, 0x3362678b
>>  0,         65,         65,        1,   149760, 0x6e7fc851
>>  0,         66,         66,        1,   149760, 0x33f96449
>> +0,         67,         67,        1,   149760, 0xd9d05007
>> +0,         75,         75,        1,   149760, 0x477f2cf2
>> +0,         76,         76,        1,   149760, 0xe1f9ccd0
>>  0,         77,         77,        1,   149760, 0xb3ba8cfb
>>  0,         78,         78,        1,   149760, 0x64787995
>>  0,         79,         79,        1,   149760, 0xc10de4c4
> 
> get_bit_length currently presumes every NALU to contain
> rbsp_trailing_bits. Yet this is not true for the End of
> Sequence/Bitstream units which are just headers without RBSP. For these
> units, get_bit_length might truncate them -- it does so for end of
> sequence units in H.264. It would not be a serious issue for H.265, as
> the semantics of nuh_temporal_id_plus1 require nuh_temporal_id_plus1 to
> be 1 for End of Sequence/Bitstream units. Nevertheless I think this
> should be coupled with a patch that does not truncate the NAL unit if it
> is just a header.
> 

1. I just sent a patch implementing the above:
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-June/297923.html
Please confirm that it actually fixes the testcase its commit message
claims to fix.
2. The RAP_B_Bossen_1 and NoOutPrior_A_Qualcomm_1 (where the testcases
change due to your patch) contain completely fine end of sequence NALUs.
Because they are valid, stripping them (as your patch does) is not ok
(e.g. these units would even be discarded when using hevc_metadata).
There are two bugs with these units:
a) Our parser puts them at the beginning of their NALUs, yet they should
be at the end of the (preceding) NALU.
b) When remuxing the samples to Matroska with mkvmerge (which puts these
units at the end of their packets), the output is the same as with raw
input, i.e. decoder still misses some frames. So somehow these units
confuse the decoder.

- Andreas
Michael Niedermayer June 24, 2022, 12:03 a.m. UTC | #4
On Wed, Jun 22, 2022 at 01:05:22PM +0200, Andreas Rheinhardt wrote:
> Andreas Rheinhardt:
> > Michael Niedermayer:
> >> Fixes: Assertion failure
> >> Fixes: 46662/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-4947860854013952
> >>
> >> This also results in more frames to be decoded from fate samples
> >>
> >> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> >> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> >> ---
> >>  libavcodec/h2645_parse.c                               |  2 +-
> >>  .../ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1  | 10 ++++++++++
> >>  tests/ref/fate/hevc-conformance-RAP_B_Bossen_1         |  3 +++
> >>  3 files changed, 14 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c
> >> index 03780680c6..78ab22b76e 100644
> >> --- a/libavcodec/h2645_parse.c
> >> +++ b/libavcodec/h2645_parse.c
> >> @@ -292,7 +292,7 @@ static int hevc_parse_nal_header(H2645NAL *nal, void *logctx)
> >>  {
> >>      GetBitContext *gb = &nal->gb;
> >>  
> >> -    if (get_bits1(gb) != 0)
> >> +    if (get_bits_left(gb) < 16 || get_bits1(gb) != 0)
> >>          return AVERROR_INVALIDDATA;
> >>  
> >>      nal->type = get_bits(gb, 6);
> >> diff --git a/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1 b/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
> >> index 0c930f6556..3283925e38 100644
> >> --- a/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
> >> +++ b/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
> >> @@ -25,6 +25,16 @@
> >>  0,         19,         19,        1,   599040, 0x4227009b
> >>  0,         20,         20,        1,   599040, 0x1bda8be4
> >>  0,         21,         21,        1,   599040, 0xd1d5dcb4
> >> +0,         22,         22,        1,   599040, 0x58b2edb3
> >> +0,         23,         23,        1,   599040, 0xd1f795d8
> >> +0,         24,         24,        1,   599040, 0x3331d5e6
> >> +0,         25,         25,        1,   599040, 0x5e5ec2c9
> >> +0,         26,         26,        1,   599040, 0x3b907bf5
> >> +0,         27,         27,        1,   599040, 0xefcbf471
> >> +0,         28,         28,        1,   599040, 0x2769a578
> >> +0,         29,         29,        1,   599040, 0x812ce986
> >> +0,         30,         30,        1,   599040, 0xf07c212c
> >> +0,         31,         31,        1,   599040, 0xb5476890
> >>  0,         32,         32,        1,   599040, 0x00a0249f
> >>  0,         33,         33,        1,   599040, 0x7263f7cf
> >>  0,         34,         34,        1,   599040, 0x47054be4
> >> diff --git a/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1 b/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
> >> index e661ff245e..776267b59c 100644
> >> --- a/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
> >> +++ b/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
> >> @@ -70,6 +70,9 @@
> >>  0,         64,         64,        1,   149760, 0x3362678b
> >>  0,         65,         65,        1,   149760, 0x6e7fc851
> >>  0,         66,         66,        1,   149760, 0x33f96449
> >> +0,         67,         67,        1,   149760, 0xd9d05007
> >> +0,         75,         75,        1,   149760, 0x477f2cf2
> >> +0,         76,         76,        1,   149760, 0xe1f9ccd0
> >>  0,         77,         77,        1,   149760, 0xb3ba8cfb
> >>  0,         78,         78,        1,   149760, 0x64787995
> >>  0,         79,         79,        1,   149760, 0xc10de4c4
> > 
> > get_bit_length currently presumes every NALU to contain
> > rbsp_trailing_bits. Yet this is not true for the End of
> > Sequence/Bitstream units which are just headers without RBSP. For these
> > units, get_bit_length might truncate them -- it does so for end of
> > sequence units in H.264. It would not be a serious issue for H.265, as
> > the semantics of nuh_temporal_id_plus1 require nuh_temporal_id_plus1 to
> > be 1 for End of Sequence/Bitstream units. Nevertheless I think this
> > should be coupled with a patch that does not truncate the NAL unit if it
> > is just a header.
> > 
> 
> 1. I just sent a patch implementing the above:
> https://ffmpeg.org/pipermail/ffmpeg-devel/2022-June/297923.html

> Please confirm that it actually fixes the testcase its commit message
> claims to fix.

confirmed!

thx

> 2. The RAP_B_Bossen_1 and NoOutPrior_A_Qualcomm_1 (where the testcases
> change due to your patch) contain completely fine end of sequence NALUs.
> Because they are valid, stripping them (as your patch does) is not ok
> (e.g. these units would even be discarded when using hevc_metadata).
> There are two bugs with these units:
> a) Our parser puts them at the beginning of their NALUs, yet they should
> be at the end of the (preceding) NALU.
> b) When remuxing the samples to Matroska with mkvmerge (which puts these
> units at the end of their packets), the output is the same as with raw
> input, i.e. decoder still misses some frames. So somehow these units
> confuse the decoder.



[...]
diff mbox series

Patch

diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c
index 03780680c6..78ab22b76e 100644
--- a/libavcodec/h2645_parse.c
+++ b/libavcodec/h2645_parse.c
@@ -292,7 +292,7 @@  static int hevc_parse_nal_header(H2645NAL *nal, void *logctx)
 {
     GetBitContext *gb = &nal->gb;
 
-    if (get_bits1(gb) != 0)
+    if (get_bits_left(gb) < 16 || get_bits1(gb) != 0)
         return AVERROR_INVALIDDATA;
 
     nal->type = get_bits(gb, 6);
diff --git a/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1 b/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
index 0c930f6556..3283925e38 100644
--- a/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
+++ b/tests/ref/fate/hevc-conformance-NoOutPrior_A_Qualcomm_1
@@ -25,6 +25,16 @@ 
 0,         19,         19,        1,   599040, 0x4227009b
 0,         20,         20,        1,   599040, 0x1bda8be4
 0,         21,         21,        1,   599040, 0xd1d5dcb4
+0,         22,         22,        1,   599040, 0x58b2edb3
+0,         23,         23,        1,   599040, 0xd1f795d8
+0,         24,         24,        1,   599040, 0x3331d5e6
+0,         25,         25,        1,   599040, 0x5e5ec2c9
+0,         26,         26,        1,   599040, 0x3b907bf5
+0,         27,         27,        1,   599040, 0xefcbf471
+0,         28,         28,        1,   599040, 0x2769a578
+0,         29,         29,        1,   599040, 0x812ce986
+0,         30,         30,        1,   599040, 0xf07c212c
+0,         31,         31,        1,   599040, 0xb5476890
 0,         32,         32,        1,   599040, 0x00a0249f
 0,         33,         33,        1,   599040, 0x7263f7cf
 0,         34,         34,        1,   599040, 0x47054be4
diff --git a/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1 b/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
index e661ff245e..776267b59c 100644
--- a/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
+++ b/tests/ref/fate/hevc-conformance-RAP_B_Bossen_1
@@ -70,6 +70,9 @@ 
 0,         64,         64,        1,   149760, 0x3362678b
 0,         65,         65,        1,   149760, 0x6e7fc851
 0,         66,         66,        1,   149760, 0x33f96449
+0,         67,         67,        1,   149760, 0xd9d05007
+0,         75,         75,        1,   149760, 0x477f2cf2
+0,         76,         76,        1,   149760, 0xe1f9ccd0
 0,         77,         77,        1,   149760, 0xb3ba8cfb
 0,         78,         78,        1,   149760, 0x64787995
 0,         79,         79,        1,   149760, 0xc10de4c4