From 2ec7e09a0cbedc6fd820cd159220f0020e10dbd7 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 23 Apr 2021 19:11:03 +0200 Subject: [PATCH] avformat/avidec: fix position overflow in avi_load_index() Fixes: signed integer overflow: 9223372033098784808 + 4294967072 cannot be represented in type 'long' Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_AVI_fuzzer-6732488912273408 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 527821a2dd6f19d9a4d2abe05833346ae86c66c6) Signed-off-by: Michael Niedermayer --- libavformat/avidec.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/libavformat/avidec.c b/libavformat/avidec.c index 3dc59a2746..cdad271a48 100644 --- a/libavformat/avidec.c +++ b/libavformat/avidec.c @@ -1736,7 +1736,10 @@ static int avi_load_index(AVFormatContext *s) size = avio_rl32(pb); if (avio_feof(pb)) break; - next = avio_tell(pb) + size + (size & 1); + next = avio_tell(pb); + if (next < 0 || next > INT64_MAX - size - (size & 1)) + break; + next += size + (size & 1LL); av_log(s, AV_LOG_TRACE, "tag=%c%c%c%c size=0x%x\n", tag & 0xff,