[FFmpeg-devel] [PATCH] lavf/mov.c: Avoid heap allocation wraps and OOB in mov_read_{senc, saiz, udta_string}()

[Matthew Wolenetz]

I've separated and updated the mov_read_{senc,saiz}() patch, attached.
It avoids allocation wraps in those two functions.

On Wed, Feb 8, 2017 at 3:48 PM, Matthew Wolenetz <wolenetz at chromium.org>
wrote:

> I've separated and updated the mov_read_udta_string() patch, attached.
> It prevents accessing MOVContext.meta_keys[0] in that method. That array
> is 1-based.
>
> On Wed, Dec 14, 2016 at 5:40 PM, Andreas Cadhalpun <
> andreas.cadhalpun at googlemail.com> wrote:
>
>> On 15.12.2016 00:37, Matthew Wolenetz wrote:
>> > From 8622f9398e7c89a664c4c2ceff9d35b89ff17bb5 Mon Sep 17 00:00:00 2001
>> > From: Matt Wolenetz <wolenetz at chromium.org>
>> > Date: Tue, 6 Dec 2016 12:54:23 -0800
>> > Subject: [PATCH] lavf/mov.c: Avoid heap allocation wraps and OOB in
>> >  mov_read_{senc,saiz,udta_string}()
>> >
>> > Core of patch is from paul at paulmehta.com
>> > Reference https://crbug.com/643952
>> > ---
>> >  libavformat/mov.c | 11 ++++++++---
>> >  1 file changed, 8 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/libavformat/mov.c b/libavformat/mov.c
>> > index e506d20..87ad91a 100644
>> > --- a/libavformat/mov.c
>> > +++ b/libavformat/mov.c
>> > @@ -404,7 +404,7 @@ retry:
>> >                  return ret;
>> >              } else if (!key && c->found_hdlr_mdta && c->meta_keys) {
>> >                  uint32_t index = AV_RB32(&atom.type);
>> > -                if (index < c->meta_keys_count) {
>> > +                if (index < c->meta_keys_count && index > 0) {
>>
>> This should be in a separate patch.
>>
>> >                      key = c->meta_keys[index];
>> >                  } else {
>> >                      av_log(c->fc, AV_LOG_WARNING,
>> > @@ -4502,8 +4502,8 @@ static int mov_read_senc(MOVContext *c,
>> AVIOContext *pb, MOVAtom atom)
>> >
>> >      avio_rb32(pb);        /* entries */
>> >
>> > -    if (atom.size < 8) {
>> > -        av_log(c->fc, AV_LOG_ERROR, "senc atom size %"PRId64" too
>> small\n", atom.size);
>> > +    if (atom.size < 8 || atom.size > UINT_MAX) {
>> > +        av_log(c->fc, AV_LOG_ERROR, "senc atom size %"PRId64"
>> invalid\n", atom.size);
>> >          return AVERROR_INVALIDDATA;
>> >      }
>> >
>> > @@ -4571,6 +4571,11 @@ static int mov_read_saiz(MOVContext *c,
>> AVIOContext *pb, MOVAtom atom)
>> >          return 0;
>> >      }
>> >
>> > +    if (atom.size > UINT_MAX) {
>> > +        av_log(c->fc, AV_LOG_ERROR, "saiz atom auxiliary_info_sizes
>> size %"PRId64" invalid\n", atom.size);
>> > +        return AVERROR_INVALIDDATA;
>> > +    }
>> > +
>> >      /* save the auxiliary info sizes as is */
>> >      data_size = atom.size - atom_header_size;
>> >
>>
>> And these should also check for SIZE_MAX.
>>
>> Best regards,
>> Andreas
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>
>
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