From 7d5b285e73de83867169299ab4e8a38823a8e8b8 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 10 Feb 2021 23:05:17 +0100 Subject: [PATCH] avcodec/sonic: Use unsigned temporary in predictor_calc_error() Fixes: signed integer overflow: -2147471366 - 18638 cannot be represented in type 'int' Fixes: 30157/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SONIC_fuzzer-5171199746506752 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 075d793ba87635b77f8302d8a454fa681f90d267) Signed-off-by: Michael Niedermayer --- libavcodec/sonic.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/sonic.c b/libavcodec/sonic.c index 2dc04846ab..9498919d2f 100644 --- a/libavcodec/sonic.c +++ b/libavcodec/sonic.c @@ -475,13 +475,13 @@ static int predictor_calc_error(int *k, int *state, int order, int error) for (i = order-2; i >= 0; i--, k_ptr--, state_ptr--) { int k_value = *k_ptr, state_value = *state_ptr; - x -= shift_down(k_value * (unsigned)state_value, LATTICE_SHIFT); + x -= (unsigned)shift_down(k_value * (unsigned)state_value, LATTICE_SHIFT); state_ptr[1] = state_value + shift_down(k_value * (unsigned)x, LATTICE_SHIFT); } #else for (i = order-2; i >= 0; i--) { - x -= shift_down(k[i] * state[i], LATTICE_SHIFT); + x -= (unsigned)shift_down(k[i] * state[i], LATTICE_SHIFT); state[i+1] = state[i] + shift_down(k[i] * x, LATTICE_SHIFT); } #endif