From 308771a73870863d1b4f630234fbb5bc7aec8252 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 7 Jul 2019 23:16:12 +0200 Subject: [PATCH] avcodec/vorbisdec: amplitude bits can be more than 25 bits Fixes: assertion failure, invalid shift Fixes: 15583/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VORBIS_fuzzer-5640157484548096 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/vorbisdec.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/libavcodec/vorbisdec.c b/libavcodec/vorbisdec.c index 00e9cd8a13..7f2d27d1a2 100644 --- a/libavcodec/vorbisdec.c +++ b/libavcodec/vorbisdec.c @@ -1097,13 +1097,14 @@ static int vorbis_floor0_decode(vorbis_context *vc, { vorbis_floor0 *vf = &vfu->t0; float *lsp = vf->lsp; - unsigned amplitude, book_idx; + unsigned book_idx; + uint64_t amplitude; unsigned blockflag = vc->modes[vc->mode_number].blockflag; if (!vf->amplitude_bits) return 1; - amplitude = get_bits(&vc->gb, vf->amplitude_bits); + amplitude = get_bits64(&vc->gb, vf->amplitude_bits); if (amplitude > 0) { float last = 0; unsigned idx, lsp_len = 0; @@ -1181,7 +1182,7 @@ static int vorbis_floor0_decode(vorbis_context *vc, /* calculate linear floor value */ q = exp((((amplitude*vf->amplitude_offset) / - (((1 << vf->amplitude_bits) - 1) * sqrt(p + q))) + (((1ULL << vf->amplitude_bits) - 1) * sqrt(p + q))) - vf->amplitude_offset) * .11512925f); /* fill vector */