[binutils-gdb] PR23141, SIGSEGV in bfd_elf_set_group_contents

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=886d542809fd73fba55ba72da1bd64ba50164222

commit 886d542809fd73fba55ba72da1bd64ba50164222
Author: Alan Modra <amodra@gmail.com>
Date:   Tue May 8 14:32:04 2018 +0930

    PR23141, SIGSEGV in bfd_elf_set_group_contents
    
    Another fuzzing fix.  I think it's reasonable to simply strip out any
    group section that is too weird for objcopy to handle.
    
    	PR 23141
    	* objcopy.c (is_strip_section): Strip groups without a valid
    	signature symbol.

Diff:
---
 binutils/ChangeLog |  6 ++++++
 binutils/objcopy.c | 11 ++++++-----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index 29fd1c2..d2d2553 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,9 @@
+2018-05-08  Alan Modra  <amodra@gmail.com>
+
+	PR 23141
+	* objcopy.c (is_strip_section): Strip groups without a valid
+	signature symbol.
+
 2018-05-07  Alan Modra  <amodra@gmail.com>
 
 	PR 23142
diff --git a/binutils/objcopy.c b/binutils/objcopy.c
index fadc957..3563792 100644
--- a/binutils/objcopy.c
+++ b/binutils/objcopy.c
@@ -1343,14 +1343,15 @@ is_strip_section (bfd *abfd ATTRIBUTE_UNUSED, asection *sec)
       const char *gname;
       asection *elt, *first;
 
+      gsym = group_signature (sec);
+      /* Strip groups without a valid signature.  */
+      if (gsym == NULL)
+	return TRUE;
+
       /* PR binutils/3181
 	 If we are going to strip the group signature symbol, then
 	 strip the group section too.  */
-      gsym = group_signature (sec);
-      if (gsym != NULL)
-	gname = gsym->name;
-      else
-	gname = sec->name;
+      gname = gsym->name;
       if ((strip_symbols == STRIP_ALL
 	   && !is_specified_symbol (gname, keep_specific_htab))
 	  || is_specified_symbol (gname, strip_specific_htab))