https://github.com/libsdl-org/libtiff/commit/eecb0712f4c3a5b449f70c57988260a667ddbdef
From eecb0712f4c3a5b449f70c57988260a667ddbdef Mon Sep 17 00:00:00 2001
From: Even Rouault <[EMAIL REDACTED]>
Date: Sun, 6 Feb 2022 13:08:38 +0100
Subject: [PATCH] TIFFFetchStripThing(): avoid calling memcpy() with a null
source pointer and size of zero (fixes #362)
---
libtiff/tif_dirread.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c
index 23194ced..50ebf8ac 100644
--- a/libtiff/tif_dirread.c
+++ b/libtiff/tif_dirread.c
@@ -5777,8 +5777,9 @@ TIFFFetchStripThing(TIFF* tif, TIFFDirEntry* dir, uint32_t nstrips, uint64_t** l
_TIFFfree(data);
return(0);
}
- _TIFFmemcpy(resizeddata,data, (uint32_t)dir->tdir_count * sizeof(uint64_t));
- _TIFFmemset(resizeddata+(uint32_t)dir->tdir_count, 0, (nstrips - (uint32_t)dir->tdir_count) * sizeof(uint64_t));
+ if( dir->tdir_count )
+ _TIFFmemcpy(resizeddata,data, (uint32_t)dir->tdir_count * sizeof(uint64_t));
+ _TIFFmemset(resizeddata+(uint32_t)dir->tdir_count, 0, (nstrips - (uint32_t)dir->tdir_count) * sizeof(uint64_t));
_TIFFfree(data);
data=resizeddata;
}