[FFmpeg-devel] [PATCH] Fix signed integer overflows

[Paul B Mahol]

On 8/22/17, Vitaly Buka <vitalybuka-at-google.com at ffmpeg.org> wrote:
> What else can I do yo make it accepted?

Ping it after month or two?

>
> On Sun, Aug 20, 2017 at 11:56 AM, Vitaly Buka <vitalybuka at google.com> wrote:
>
>> Signed integer overflow is undefined behavior.
>> Detected with clang and -fsanitize=signed-integer-overflow
>>
>> Signed-off-by: Vitaly Buka <vitalybuka at google.com>
>> ---
>>  libavcodec/utils.c    | 2 +-
>>  libavformat/aviobuf.c | 2 ++
>>  libavformat/mov.c     | 2 +-
>>  3 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/libavcodec/utils.c b/libavcodec/utils.c
>> index 1336e921c9..1b8ad1d200 100644
>> --- a/libavcodec/utils.c
>> +++ b/libavcodec/utils.c
>> @@ -971,7 +971,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
>>          }
>>
>>          if (!avctx->rc_initial_buffer_occupancy)
>> -            avctx->rc_initial_buffer_occupancy = avctx->rc_buffer_size *
>> 3 / 4;
>> +            avctx->rc_initial_buffer_occupancy = avctx->rc_buffer_size *
>> 3LL / 4;
>>
>>          if (avctx->ticks_per_frame && avctx->time_base.num &&
>>              avctx->ticks_per_frame > INT_MAX / avctx->time_base.num) {
>> diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
>> index 7f4e740a33..ec21fc7d38 100644
>> --- a/libavformat/aviobuf.c
>> +++ b/libavformat/aviobuf.c
>> @@ -259,6 +259,8 @@ int64_t avio_seek(AVIOContext *s, int64_t offset, int
>> whence)
>>          offset1 = pos + (s->buf_ptr - s->buffer);
>>          if (offset == 0)
>>              return offset1;
>> +        if (offset > INT64_MAX - offset1)
>> +            return AVERROR(EINVAL);
>>          offset += offset1;
>>      }
>>      if (offset < 0)
>> diff --git a/libavformat/mov.c b/libavformat/mov.c
>> index 522ce60c2d..a14c9f182b 100644
>> --- a/libavformat/mov.c
>> +++ b/libavformat/mov.c
>> @@ -5572,7 +5572,7 @@ static int mov_read_default(MOVContext *c,
>> AVIOContext *pb, MOVAtom atom)
>>
>>      if (atom.size < 0)
>>          atom.size = INT64_MAX;
>> -    while (total_size + 8 <= atom.size && !avio_feof(pb)) {
>> +    while (total_size <= atom.size - 8 && !avio_feof(pb)) {
>>          int (*parse)(MOVContext*, AVIOContext*, MOVAtom) = NULL;
>>          a.size = atom.size;
>>          a.type=0;
>> --
>> 2.14.1.480.gb18f417b89-goog
>>
>>
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