Michael Niedermayer: > Fixes: signed integer overflow: 2147483647 + 1 cannot be represented in type > 'int' > Fixes: > 45891/clusterfuzz-testcase-minimized-ffmpeg_dem_AIFF_fuzzer-6159183893889024 > > Found-by: continuous fuzzing process > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > --- > libavformat/aiffdec.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/libavformat/aiffdec.c b/libavformat/aiffdec.c > index 3634bb4960..c2b8e0dede 100644 > --- a/libavformat/aiffdec.c > +++ b/libavformat/aiffdec.c > @@ -72,7 +72,12 @@ static int get_tag(AVIOContext *pb, uint32_t * tag) > /* Metadata string read */ > static void get_meta(AVFormatContext *s, const char *key, int size) > { > - uint8_t *str = av_malloc(size+1); > + uint8_t *str; > + > + if (size == INT_MAX) > + return; > + > + str = av_malloc(size+1); > > if (str) { > int res = avio_read(s->pb, str, size);
If a size of INT_MAX is legal, then you can just use "size + 1U" to avoid the wraparound. (The allocation will then fail with the default value of max_alloc_size and in this case the avio_skip() will be executed, so that we don't lose sync (your patch does that).) Looking at get_tag() shows that the size actually comes from a uint32_t which gets truncated to INT_MAX if it is not representable in an int. I don't know whether the specs mandate this behaviour (probably not, so one loses sync). If one wanted to impose an arbitrary limit, I will use something much smaller than INT_MAX. - Andreas _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
