From 43e5e2e42354fafc608830e3c8c46dacd22a851b Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 18 Feb 2023 21:50:13 +0100 Subject: [PATCH] avcodec/bonk: Avoid undefined integer overflow in predictor_calc_error() Fixes: signed integer overflow: -159584 * 5105950 cannot be represented in type 'int' Fixes: 55165/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BONK_fuzzer-5796023719297024 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/bonk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/bonk.c b/libavcodec/bonk.c index 9a91b4842e..fbea91c750 100644 --- a/libavcodec/bonk.c +++ b/libavcodec/bonk.c @@ -270,14 +270,14 @@ static inline int shift(int a, int b) static int predictor_calc_error(int *k, int *state, int order, int error) { - int i, x = error - shift_down(k[order-1] * state[order-1], LATTICE_SHIFT); + int i, x = error - shift_down(k[order-1] * (unsigned)state[order-1], LATTICE_SHIFT); int *k_ptr = &(k[order-2]), *state_ptr = &(state[order-2]); for (i = order-2; i >= 0; i--, k_ptr--, state_ptr--) { unsigned k_value = *k_ptr, state_value = *state_ptr; - x -= shift_down(k_value * state_value, LATTICE_SHIFT); + x -= shift_down(k_value * (unsigned)state_value, LATTICE_SHIFT); state_ptr[1] = state_value + shift_down(k_value * x, LATTICE_SHIFT); }