From 8c50704ebf1777bee76772c4835d9760b3721057 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 4 Oct 2014 03:12:34 +0200 Subject: avcodec/vorbisdec: Fix off by 1 error in ptns_to_read Fixes read of uninitialized memory Fixes: asan_heap-uaf_18dac2b_9_asan_heap-uaf_22eb375_208_beta3_test_small.ogg Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libavcodec/vorbisdec.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'libavcodec/vorbisdec.c') diff --git a/libavcodec/vorbisdec.c b/libavcodec/vorbisdec.c index 87d1bbb97a..354ab0e466 100644 --- a/libavcodec/vorbisdec.c +++ b/libavcodec/vorbisdec.c @@ -1314,7 +1314,9 @@ static av_always_inline int setup_classifs(vorbis_context *vc, vorbis_residue *vr, uint8_t *do_not_decode, unsigned ch_used, - int partition_count) + int partition_count, + int ptns_to_read + ) { int p, j, i; unsigned c_p_c = vc->codebooks[vr->classbook].dimensions; @@ -1336,7 +1338,7 @@ static av_always_inline int setup_classifs(vorbis_context *vc, for (i = partition_count + c_p_c - 1; i >= partition_count; i--) { temp2 = (((uint64_t)temp) * inverse_class) >> 32; - if (i < vr->ptns_to_read) + if (i < ptns_to_read) vr->classifs[p + i] = temp - temp2 * vr->classifications; temp = temp2; } @@ -1344,13 +1346,13 @@ static av_always_inline int setup_classifs(vorbis_context *vc, for (i = partition_count + c_p_c - 1; i >= partition_count; i--) { temp2 = temp / vr->classifications; - if (i < vr->ptns_to_read) + if (i < ptns_to_read) vr->classifs[p + i] = temp - temp2 * vr->classifications; temp = temp2; } } } - p += vr->ptns_to_read; + p += ptns_to_read; } return 0; } @@ -1404,7 +1406,7 @@ static av_always_inline int vorbis_residue_decode_internal(vorbis_context *vc, for (partition_count = 0; partition_count < ptns_to_read;) { // SPEC error if (!pass) { int ret; - if ((ret = setup_classifs(vc, vr, do_not_decode, ch_used, partition_count)) < 0) + if ((ret = setup_classifs(vc, vr, do_not_decode, ch_used, partition_count, ptns_to_read)) < 0) return ret; } for (i = 0; (i < c_p_c) && (partition_count < ptns_to_read); ++i) { -- cgit v1.2.3