[FFmpeg-devel] [PR] avformat/lrcdec: Check ss for finiteness (PR #21751)

[FFmpeg-devel] [PR] avformat/lrcdec: Check ss for finiteness (PR #21751)

[michaelni via ffmpeg-devel]

PR #21751 opened by michaelni
URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21751
Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21751.patch

Fixes: negation of -9223372036854775808 cannot be represented in type 'int64_t' (aka 'long'); cast to an unsigned type to negate this value to itself
Fixes: 471604230/clusterfuzz-testcase-minimized-ffmpeg_dem_LRC_fuzzer-5474264750030848

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>


>From 3fe5142293c5040f15fe2444270eafdffc48736c Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Sat, 14 Feb 2026 00:26:23 +0100
Subject: [PATCH] avformat/lrcdec: Check ss for finiteness

Fixes: negation of -9223372036854775808 cannot be represented in type 'int64_t' (aka 'long'); cast to an unsigned type to negate this value to itself
Fixes: 471604230/clusterfuzz-testcase-minimized-ffmpeg_dem_LRC_fuzzer-5474264750030848

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

diff --git a/libavformat/lrcdec.c b/libavformat/lrcdec.c
index b323c59f59..1f96305693 100644
--- a/libavformat/lrcdec.c
+++ b/libavformat/lrcdec.c
@@ -89,7 +89,7 @@ static int64_t read_ts(const char *p, int64_t *start)
         return 0;
     }
     int ret = av_sscanf(p, "%2[[-]%"SCNu32":%lf]", prefix, &mm, &ss);
-    if (ret != 3 || prefix[0] != '[' || ss < 0 || ss > 60) {
+    if (ret != 3 || prefix[0] != '[' || ss < 0 || ss > 60 || !isfinite(ss)) {
         return 0;
     }
     *start = llrint((mm * 60 + ss) * AV_TIME_BASE);
-- 
2.52.0

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