From: Alan Modra <amodra@gmail.com>
Date: Wed, 26 Aug 2020 09:02:30 +0000 (+0930)
Subject: PR26478 UBSAN: mmo.c:2941 null pointer memcpy
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=00bc5e68b2c02fd2b1daacc37850840498595fb0;p=binutils-gdb.git

PR26478 UBSAN: mmo.c:2941 null pointer memcpy

	PR 26478
	* mmo.c (mmo_write_symbols_and_terminator): Don't memcpy empty table.
---

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 3a85c3eb9a5..86fccfb79d9 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2020-08-26  Alan Modra  <amodra@gmail.com>
+
+	PR 26478
+	* mmo.c (mmo_write_symbols_and_terminator): Don't memcpy empty table.
+
 2020-08-26  Alan Modra  <amodra@gmail.com>
 
 	PR 26475
diff --git a/bfd/mmo.c b/bfd/mmo.c
index 5209736a505..92c51a4f637 100644
--- a/bfd/mmo.c
+++ b/bfd/mmo.c
@@ -2938,7 +2938,8 @@ mmo_write_symbols_and_terminator (bfd *abfd)
   if (table == NULL)
     return FALSE;
 
-  memcpy (table, orig_table, count * sizeof (asymbol *));
+  if (count != 0)
+    memcpy (table, orig_table, count * sizeof (asymbol *));
 
   /* Move :Main (if there is one) to the first position.  This is
      necessary to get the same layout of the trie-tree when linking as