From 8fbcc546b83e2ce242a0b75054ec2ca304a171df Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 23 Oct 2020 10:48:36 +0200 Subject: [PATCH] tools/target_dem_fuzzer: Consider it an EIO when reading position wraps around 64bit Fixes: signed integer overflow: 9223372036854775807 + 564 cannot be represented in type 'long' Fixes: 26494/clusterfuzz-testcase-minimized-ffmpeg_dem_VOC_fuzzer-576754158849228 Fixes: 26549/clusterfuzz-testcase-minimized-ffmpeg_dem_AVS_fuzzer-4844306424397824 FIxes: 26875/clusterfuzz-testcase-minimized-ffmpeg_dem_C93_fuzzer-5996226782429184 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- tools/target_dem_fuzzer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/target_dem_fuzzer.c b/tools/target_dem_fuzzer.c index 6f4f062f13..e4f41765d6 100644 --- a/tools/target_dem_fuzzer.c +++ b/tools/target_dem_fuzzer.c @@ -49,6 +49,8 @@ static int io_read(void *opaque, uint8_t *buf, int buf_size) c->filesize = FFMIN(c->pos, c->filesize); return AVERROR_EOF; } + if (c->pos > INT64_MAX - size) + return AVERROR(EIO); memcpy(buf, c->fuzz, size); c->fuzz += size;