[binutils-gdb] PR23804, buffer overflow in sec_merge_hash_lookup

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ab419ddbb2cdd17ca83618990f2cacf904ce1d61

commit ab419ddbb2cdd17ca83618990f2cacf904ce1d61
Author: Alan Modra <amodra@gmail.com>
Date:   Tue Oct 23 18:29:24 2018 +1030

    PR23804, buffer overflow in sec_merge_hash_lookup
    
    	PR 23804
    	* merge.c (_bfd_add_merge_section): Don't attempt to merge
    	sections where size is not a multiple of entsize.

Diff:
---
 bfd/ChangeLog | 6 ++++++
 bfd/merge.c   | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 31ff3d6..da423b1 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2018-10-23  Alan Modra  <amodra@gmail.com>
+
+	PR 23804
+	* merge.c (_bfd_add_merge_section): Don't attempt to merge
+	sections where size is not a multiple of entsize.
+
 2018-10-20  Alan Modra  <amodra@gmail.com>
 
 	PR 23788
diff --git a/bfd/merge.c b/bfd/merge.c
index 7904552..5e3bba0 100644
--- a/bfd/merge.c
+++ b/bfd/merge.c
@@ -376,6 +376,9 @@ _bfd_add_merge_section (bfd *abfd, void **psinfo, asection *sec,
       || sec->entsize == 0)
     return TRUE;
 
+  if (sec->size % sec->entsize != 0)
+    return TRUE;
+
   if ((sec->flags & SEC_RELOC) != 0)
     {
       /* We aren't prepared to handle relocations in merged sections.  */