From 57e18185bf23d3b05374681bb1f3168e320ad66f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 23 Sep 2020 23:31:59 +0200 Subject: avcodec/celp_filters: Avoid invalid negation in ff_celp_lp_synthesis_filter() Fixes: negation of -2147483648 cannot be represented in type 'int'; cast to an unsigned type to negate this value to itself Fixes: 25675/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_G729_fuzzer-4786580731199488 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 11a6347f9e544a1b9fba059ae02c30c0e512c195) Signed-off-by: Michael Niedermayer --- libavcodec/celp_filters.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'libavcodec') diff --git a/libavcodec/celp_filters.c b/libavcodec/celp_filters.c index fafedd99a3..40ff7427df 100644 --- a/libavcodec/celp_filters.c +++ b/libavcodec/celp_filters.c @@ -65,11 +65,11 @@ int ff_celp_lp_synthesis_filter(int16_t *out, const int16_t *filter_coeffs, int i,n; for (n = 0; n < buffer_length; n++) { - int sum = -rounder, sum1; + int sum = rounder, sum1; for (i = 1; i <= filter_length; i++) - sum += (unsigned)(filter_coeffs[i-1] * out[n-i]); + sum -= (unsigned)(filter_coeffs[i-1] * out[n-i]); - sum1 = ((-sum >> 12) + in[n]) >> shift; + sum1 = ((sum >> 12) + in[n]) >> shift; sum = av_clip_int16(sum1); if (stop_on_overflow && sum != sum1) -- cgit v1.2.3