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| author | Alex Converse <alex.converse@gmail.com> | 2012-01-25 13:39:24 -0800 |
|---|---|---|
| committer | Reinhard Tartler <siretart@tauware.de> | 2012-02-28 22:20:45 +0100 |
| commit | 083a8a00373b12dc06b8ae4c49eec61fb5e55f4b (patch) | |
| tree | dac1f91b30bca4ccbc4c555ac902f9b5e2b83002 | |
| parent | 71a939fee47d8b59ba1258b481322d16378e556f (diff) | |
| download | ffmpeg-083a8a00373b12dc06b8ae4c49eec61fb5e55f4b.tar.gz | |
mjpegbdec: Fix overflow in SOS.
Based in part by a fix from Michael Niedermayer <michaelni@gmx.at>
Fixes CVE-2011-3947
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
(cherry picked from commit b57d262412204e54a7ef8fa1b23ff4dcede622e5)
Signed-off-by: Reinhard Tartler <siretart@tauware.de>
| -rw-r--r-- | libavcodec/mjpegbdec.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/libavcodec/mjpegbdec.c b/libavcodec/mjpegbdec.c index 9f71f508ae..10c5addca0 100644 --- a/libavcodec/mjpegbdec.c +++ b/libavcodec/mjpegbdec.c @@ -59,6 +59,9 @@ read_header: s->restart_count = 0; s->mjpb_skiptosod = 0; + if (buf_end - buf_ptr >= 1 << 28) + return AVERROR_INVALIDDATA; + init_get_bits(&hgb, buf_ptr, /*buf_size*/(buf_end - buf_ptr)*8); skip_bits(&hgb, 32); /* reserved zeros */ @@ -111,8 +114,8 @@ read_header: av_log(avctx, AV_LOG_DEBUG, "sod offs: 0x%x\n", sod_offs); if (sos_offs) { -// init_get_bits(&s->gb, buf+sos_offs, (buf_end - (buf+sos_offs))*8); - init_get_bits(&s->gb, buf_ptr+sos_offs, field_size*8); + init_get_bits(&s->gb, buf_ptr + sos_offs, + 8 * FFMIN(field_size, buf_end - buf_ptr - sos_offs)); s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16)); s->start_code = SOS; if (ff_mjpeg_decode_sos(s, NULL, NULL) < 0 && |