PR23804, buffer overflow in sec_merge_hash_lookup

[Alan Modra]

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

diff --git a/bfd/merge.c b/bfd/merge.c
index 7904552942..5e3bba0982 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. */