From c5f265bb2468c3e0996329ada11b2792dd9bd1a2 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 15 Jun 2019 21:34:18 +0200 Subject: [PATCH] avcodec/atrac9dec: Check conditions before apply_band_extension() to avoid out of array read in initialization of unused variables Fixes: global-buffer-overflow Fixes: 15247/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ATRAC9_fuzzer-5671602181636096 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/atrac9dec.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/libavcodec/atrac9dec.c b/libavcodec/atrac9dec.c index 4d490daeb0..2e23ea44e8 100644 --- a/libavcodec/atrac9dec.c +++ b/libavcodec/atrac9dec.c @@ -539,9 +539,6 @@ static inline void apply_band_extension(ATRAC9Context *s, ATRAC9BlockData *b, at9_q_unit_to_coeff_idx[g_units[3]], }; - if (!b->has_band_ext || !b->has_band_ext_data) - return; - for (int ch = 0; ch <= stereo; ch++) { ATRAC9ChannelData *c = &b->channel[ch]; @@ -751,7 +748,9 @@ static int atrac9_decode_block(ATRAC9Context *s, GetBitContext *gb, apply_intensity_stereo(s, b, stereo); apply_scalefactors (s, b, stereo); - apply_band_extension (s, b, stereo); + + if (b->has_band_ext && b->has_band_ext_data) + apply_band_extension (s, b, stereo); imdct: for (int i = 0; i <= stereo; i++) {