From 56933f9e3e90eebf1018ed7417d6c1184b91db6b Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 22 Sep 2017 14:15:40 -0700
Subject: [PATCH 1/1] x86: Guard against corrupted PLT

There should be only one entry in PLT for a given symbol.  Set howto to
NULL after processing a PLT entry to guard against corrupted PLT so that
the duplicated PLT entries are skipped.

	PR binutils/22170
	 * elf32-i386.c (elf_i386_get_synthetic_symtab): Guard against
	 corrupted PLT.
	 * elf64-x86-64.c (elf_x86_64_get_synthetic_symtab): Likewise.

(cherry picked from commit 61e3bf5f83f7e505b6bc51ef65426e5b31e6e360)
---
 bfd/elf32-i386.c   | 4 ++++
 bfd/elf64-x86-64.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 9dc2d25..ba50c93 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -6616,6 +6616,10 @@ bad_return:
 		  size += sizeof ("+0x") - 1 + 8;
 		n++;
 		s++;
+		/* There should be only one entry in PLT for a given
+		   symbol.  Set howto to NULL after processing a PLT
+		   entry to guard against corrupted PLT.  */
+		p->howto = NULL;
 	      }
 	    offset += plt_entry_size;
 	  }
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 558db98..d9225ad 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -6970,6 +6970,10 @@ bad_return:
 		  size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd);
 		n++;
 		s++;
+		/* There should be only one entry in PLT for a given
+		   symbol.  Set howto to NULL after processing a PLT
+		   entry to guard against corrupted PLT.  */
+		p->howto = NULL;
 	      }
 	    offset += plt_entry_size;
 	  }