[FFmpeg-devel] [PATCH] avcodec/pnmdec: Use unsigned for maxval rescaling

Michael Niedermayer michael at niedermayer.cc
Sat May 16 19:37:32 EEST 2020


Fixes: signed integer overflow: 65535 * 55335 cannot be represented in type 'int'
Fixes: 21955/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PGMYUV_fuzzer-5669206981083136

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/pnmdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/pnmdec.c b/libavcodec/pnmdec.c
index dbcaef38848..e03e52297f7 100644
--- a/libavcodec/pnmdec.c
+++ b/libavcodec/pnmdec.c
@@ -132,7 +132,7 @@ static int pnm_decode_frame(AVCodecContext *avctx, void *data,
                 init_put_bits(&pb, ptr, linesize);
                 for(j=0; j<avctx->width * components; j++){
                     unsigned int c=0;
-                    int v=0;
+                    unsigned v=0;
                     if(s->type < 4)
                     while(s->bytestream < s->bytestream_end && (*s->bytestream < '0' || *s->bytestream > '9' ))
                         s->bytestream++;
-- 
2.17.1



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