[binutils-gdb] PR24337, segfault in _bfd_elf_rela_local_sym, again

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6835821be8bab8702e41e6946a7d8ee9441f0eee

commit 6835821be8bab8702e41e6946a7d8ee9441f0eee
Author: Alan Modra <amodra@gmail.com>
Date:   Sat Mar 16 09:34:47 2019 +1030

    PR24337, segfault in _bfd_elf_rela_local_sym, again
    
    Reverts commit 1ff31e135f, fixing the problem more generally.  There
    are likely other place that will segfault on a NULL section.
    
    	PR 24337
    	* elf.c (_bfd_elf_rela_local_sym): Revert last change.
    	(_bfd_elf_rel_local_sym): Likewise.
    	* elflink.c (elf_link_input_bfd): Use bfd_und_section for
    	section of symbols with unrecognized shndx.

Diff:
---
 bfd/ChangeLog | 8 ++++++++
 bfd/elf.c     | 9 ++++-----
 bfd/elflink.c | 5 ++---
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index b019ca6..f92b273 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2019-03-16  Alan Modra  <amodra@gmail.com>
+
+	PR 24337
+	* elf.c (_bfd_elf_rela_local_sym): Revert last change.
+	(_bfd_elf_rel_local_sym): Likewise.
+	* elflink.c (elf_link_input_bfd): Use bfd_und_section for
+	section of symbols with unrecognized shndx.
+
 2019-03-15  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/24267
diff --git a/bfd/elf.c b/bfd/elf.c
index 585bf3c..73fb869 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -11822,10 +11822,9 @@ _bfd_elf_rela_local_sym (bfd *abfd,
   asection *sec = *psec;
   bfd_vma relocation;
 
-  relocation = sym->st_value;
-  if (sec == NULL)
-    return relocation;
-  relocation += sec->output_section->vma + sec->output_offset;
+  relocation = (sec->output_section->vma
+		+ sec->output_offset
+		+ sym->st_value);
   if ((sec->flags & SEC_MERGE)
       && ELF_ST_TYPE (sym->st_info) == STT_SECTION
       && sec->sec_info_type == SEC_INFO_TYPE_MERGE)
@@ -11859,7 +11858,7 @@ _bfd_elf_rel_local_sym (bfd *abfd,
 {
   asection *sec = *psec;
 
-  if (sec == NULL || sec->sec_info_type != SEC_INFO_TYPE_MERGE)
+  if (sec->sec_info_type != SEC_INFO_TYPE_MERGE)
     return sym->st_value + addend;
 
   return _bfd_merged_section_offset (abfd, psec,
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 09990a4..c796e27 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -4446,7 +4446,7 @@ error_free_dyn:
 	    continue;
 
 	  /* If we aren't prepared to handle locals within the globals
-	      then we'll likely segfault on a NULL section.  */
+	     then we'll likely segfault on a NULL section.  */
 	  bfd_set_error (bfd_error_bad_value);
 	  goto error_free_vers;
 
@@ -10421,8 +10421,7 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
 	    {
 	      /* Don't attempt to output symbols with st_shnx in the
 		 reserved range other than SHN_ABS and SHN_COMMON.  */
-	      *ppsection = NULL;
-	      continue;
+	      isec = bfd_und_section_ptr;
 	    }
 	  else if (isec->sec_info_type == SEC_INFO_TYPE_MERGE
 		   && ELF_ST_TYPE (isym->st_info) != STT_SECTION)