The addition is moved up into the context where the variable is unsigned avoiding the undefined behavior
Fixes: runtime error: signed integer overflow: 2147481972 + 4096 cannot be represented in type 'int' Fixes: 12444/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ILBC_fuzzer-5755706244857856 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> --- libavcodec/ilbcdec.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libavcodec/ilbcdec.c b/libavcodec/ilbcdec.c index 643547f4ab..bba83a5896 100644 --- a/libavcodec/ilbcdec.c +++ b/libavcodec/ilbcdec.c @@ -408,11 +408,11 @@ static void lsf2poly(int16_t *a, int16_t *lsf) a[0] = 4096; for (i = 5; i > 0; i--) { - tmp = f[0][6 - i] + (unsigned)f[1][6 - i]; - a[6 - i] = (tmp + 4096) >> 13; + tmp = f[0][6 - i] + (unsigned)f[1][6 - i] + 4096; + a[6 - i] = tmp >> 13; - tmp = f[0][6 - i] - (unsigned)f[1][6 - i]; - a[5 + i] = (tmp + 4096) >> 13; + tmp = f[0][6 - i] - (unsigned)f[1][6 - i] + 4096; + a[5 + i] = tmp >> 13; } } -- 2.20.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
