https://github.com/libsdl-org/libtiff/commit/a95b799f65064e4ba2e2dfc206808f86faf93e85
From a95b799f65064e4ba2e2dfc206808f86faf93e85 Mon Sep 17 00:00:00 2001
From: Even Rouault <[EMAIL REDACTED]>
Date: Thu, 17 Feb 2022 15:28:43 +0100
Subject: [PATCH] TIFFFetchNormalTag(): avoid calling memcpy() with a null
source pointer and size of zero (fixes #383)
---
libtiff/tif_dirread.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c
index 50ebf8ac..2ec44a4f 100644
--- a/libtiff/tif_dirread.c
+++ b/libtiff/tif_dirread.c
@@ -5091,7 +5091,10 @@ TIFFFetchNormalTag(TIFF* tif, TIFFDirEntry* dp, int recover)
_TIFFfree(data);
return(0);
}
- _TIFFmemcpy(o,data,(uint32_t)dp->tdir_count);
+ if (dp->tdir_count > 0 )
+ {
+ _TIFFmemcpy(o,data,(uint32_t)dp->tdir_count);
+ }
o[(uint32_t)dp->tdir_count]=0;
if (data!=0)
_TIFFfree(data);