[FFmpeg-devel] [PATCH 3/5] avcodec/apedec: Use FFNABS() in do_apply_filter()

Michael Niedermayer michael at niedermayer.cc
Thu Jan 21 02:03:44 EET 2021


Fixes: negation of -2147483648 cannot be represented in type 'int'; cast to an unsigned type to negate this value to itself
Fixes: 29053/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-4814432697974784

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/apedec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index 8fe7b5ee86..385e003c6a 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -1333,7 +1333,7 @@ static void do_apply_filter(APEContext *ctx, int version, APEFilter *f,
             /* Version 3.98 and later files */
 
             /* Update the adaption coefficients */
-            absres = FFABS(res);
+            absres = -(unsigned)FFNABS(res);
             if (absres)
                 *f->adaptcoeffs = APESIGN(res) *
                                   (8 << ((absres > f->avg * 3) + (absres > f->avg * 4 / 3)));
-- 
2.17.1



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