From bce93faf38a0db31ad314ce8eb9488970580309d Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 11 Sep 2022 00:11:20 +0200 Subject: avcodec/tta: Check 24bit scaling for overflow Fixes: signed integer overflow: -8427924 * 256 cannot be represented in type 'int' Fixes: 48798/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TTA_fuzzer-5409428670644224 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 3993345f915bccceee315f44d412445346990e14) Signed-off-by: Michael Niedermayer --- libavcodec/tta.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/libavcodec/tta.c b/libavcodec/tta.c index b2e4944905..39f532bba3 100644 --- a/libavcodec/tta.c +++ b/libavcodec/tta.c @@ -371,8 +371,15 @@ static int tta_decode_frame(AVCodecContext *avctx, void *data, case 3: { // shift samples for 24-bit sample format int32_t *samples = (int32_t *)frame->data[0]; - for (i = 0; i < framelen * s->channels; i++) - *samples++ *= 256; + int overflow = 0; + + for (i = 0; i < framelen * s->channels; i++) { + int scaled = *samples * 256U; + overflow += (scaled >> 8 != *samples); + *samples++ = scaled; + } + if (overflow) + av_log(avctx, AV_LOG_WARNING, "%d overflows occurred on 24bit upscale\n", overflow); // reset decode buffer s->decode_buffer = NULL; break; -- cgit v1.2.1