avcodec/jpeg2000dec: Check precno before using it in JPEG2000_PGOD_CPRL

Fixes out of array reads Fixes: asan_heap-oob_f0de57_6823_mjp2.mov Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
11 years ago · 3d5a5e86be
parent 638d79a9d0
commit 3d5a5e86be
1 changed files with 4 additions and 0 deletions
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@ -889,6 +889,10 @@ static int jpeg2000_decode_packets(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile
                        prcx   = ff_jpeg2000_ceildivpow2(x, reducedresno) >> rlevel->log2_prec_width;
                        prcy   = ff_jpeg2000_ceildivpow2(y, reducedresno) >> rlevel->log2_prec_height;
                        precno = prcx + rlevel->num_precincts_x * prcy;
+
+                        if (prcx >= rlevel->num_precincts_x || prcy >= rlevel->num_precincts_y)
+                            return AVERROR_PATCHWELCOME;
+
                        for (layno = 0; layno < tile->codsty[0].nlayers; layno++) {
                            if ((ret = jpeg2000_decode_packet(s, codsty, rlevel,
                                                              precno, layno,