avformat/3dostr: Check remaining buffer in probe before 8 byte step

Fixes: segfault Fixes: signal_sigabrt_7ffff6ae7cc9_7213_0d6457b9d6897fa7c78507fa5de53510.ts Regression since: 3ac45bf665 Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
5 years ago · 624f6df19f
parent d54c24acde
commit 624f6df19f
1 changed files with 1 additions and 2 deletions
--- a/libavformat/3dostr.c
+++ b/libavformat/3dostr.c
@ -29,10 +29,9 @@ static int threedostr_probe(const AVProbeData *p)
        unsigned chunk = AV_RL32(p->buf + i);
        unsigned size  = AV_RB32(p->buf + i + 4);

-        i += 8;
        if (size < 8 || p->buf_size - i < size)
            return 0;
-
+        i += 8;
        size -= 8;
        switch (chunk) {
        case MKTAG('C','T','R','L'):