From 112a077d06585e5cf5efcff76c15a1760b0bb455 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 19 Sep 2023 01:24:37 +0200 Subject: [PATCH] avcodec/flacdec: Fix integer overflow in "33bit" DECODER_SUBFRAME_FIXED_WIDE() Fixes: signed integer overflow: 4 * 2307917133220067266 cannot be represented in type 'long' Fixes: 62164/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FLAC_fuzzer-6307690022043648 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/flacdec.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libavcodec/flacdec.c b/libavcodec/flacdec.c index 0569f019b3..ed2de14d0a 100644 --- a/libavcodec/flacdec.c +++ b/libavcodec/flacdec.c @@ -366,19 +366,19 @@ static int decode_subframe_fixed(FLACContext *s, int32_t *decoded, break; \ case 1: \ for (int i = pred_order; i < blocksize; i++) \ - decoded[i] = (int64_t)residual[i] + (int64_t)decoded[i-1];\ + decoded[i] = (uint64_t)residual[i] + (uint64_t)decoded[i-1];\ break; \ case 2: \ for (int i = pred_order; i < blocksize; i++) \ - decoded[i] = (int64_t)residual[i] + 2*(int64_t)decoded[i-1] - (int64_t)decoded[i-2]; \ + decoded[i] = (uint64_t)residual[i] + 2*(uint64_t)decoded[i-1] - (uint64_t)decoded[i-2]; \ break; \ case 3: \ for (int i = pred_order; i < blocksize; i++) \ - decoded[i] = (int64_t)residual[i] + 3*(int64_t)decoded[i-1] - 3*(int64_t)decoded[i-2] + (int64_t)decoded[i-3]; \ + decoded[i] = (uint64_t)residual[i] + 3*(uint64_t)decoded[i-1] - 3*(uint64_t)decoded[i-2] + (uint64_t)decoded[i-3]; \ break; \ case 4: \ for (int i = pred_order; i < blocksize; i++) \ - decoded[i] = (int64_t)residual[i] + 4*(int64_t)decoded[i-1] - 6*(int64_t)decoded[i-2] + 4*(int64_t)decoded[i-3] - (int64_t)decoded[i-4]; \ + decoded[i] = (uint64_t)residual[i] + 4*(uint64_t)decoded[i-1] - 6*(uint64_t)decoded[i-2] + 4*(uint64_t)decoded[i-3] - (uint64_t)decoded[i-4]; \ break; \ default: \ av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order); \