avformat/mov: check atom nesting depth

Fixes call stack overflow
Fixes: case1_call_stack_overflow.mp4
Found-by: Michal Zalewski <lcamtuf@coredump.cx>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2014-12-16 21:14:40 +01:00
parent 3881606240
commit caa7a3914f
2 changed files with 13 additions and 1 deletions

View File

@ -190,6 +190,7 @@ typedef struct MOVContext {
int has_looked_for_mfra;
MOVFragmentIndex** fragment_index_data;
unsigned fragment_index_count;
int atom_depth;
} MOVContext;
int ff_mp4_read_descr_len(AVIOContext *pb);

View File

@ -3412,6 +3412,12 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
MOVAtom a;
int i;
if (c->atom_depth > 10) {
av_log(c->fc, AV_LOG_ERROR, "Atoms too deeply nested\n");
return AVERROR_INVALIDDATA;
}
c->atom_depth ++;
if (atom.size < 0)
atom.size = INT64_MAX;
while (total_size + 8 <= atom.size && !avio_feof(pb)) {
@ -3441,6 +3447,7 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
av_log(c->fc, AV_LOG_ERROR, "Broken file, trak/mdat not at top-level\n");
avio_skip(pb, -8);
c->atom_depth --;
return 0;
}
}
@ -3477,13 +3484,16 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
int64_t start_pos = avio_tell(pb);
int64_t left;
int err = parse(c, pb, a);
if (err < 0)
if (err < 0) {
c->atom_depth --;
return err;
}
if (c->found_moov && c->found_mdat &&
((!pb->seekable || c->fc->flags & AVFMT_FLAG_IGNIDX) ||
start_pos + a.size == avio_size(pb))) {
if (!pb->seekable || c->fc->flags & AVFMT_FLAG_IGNIDX)
c->next_root_atom = start_pos + a.size;
c->atom_depth --;
return 0;
}
left = a.size - avio_tell(pb) + start_pos;
@ -3503,6 +3513,7 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
if (total_size < atom.size && atom.size < 0x7ffff)
avio_skip(pb, atom.size - total_size);
c->atom_depth --;
return 0;
}