From: Alan Modra <amodra@gmail.com>
Date: Wed, 20 Nov 2019 22:27:00 +0000 (+1030)
Subject: ARM cmse_scan segfault
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=73d5efd7e13ebd8fe87278224bc2ae777af3de52;p=binutils-gdb.git

ARM cmse_scan segfault

This code in elf_link_add_object_symbols:

      ret = elf_add_dt_needed_tag (abfd, info, soname, add_needed);
      if (ret < 0)
	goto error_return;

      /* If we have already included this dynamic object in the
	 link, just ignore it.  There is no reason to include a
	 particular dynamic object more than once.  */
      if (ret > 0)
	return TRUE;

prevents a shared library from being loaded twice by ensuring that any
library soname doesn't match the soname of one already loaded.  This
happens before sym_hashes are allocated, which leaves sym_hashes NULL.

cmse_scan looks at library symbols, and when attempting to look up a
global symbol will segfault if sym_hashes is zero.

	* elf32-arm.c (elf32_arm_size_stubs): Exclude dynamic library
	BFDs that have not been loaded.
---

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index ffe527c52a3..a1ef734af6a 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2019-11-21  Alan Modra  <amodra@gmail.com>
+
+	* elf32-arm.c (elf32_arm_size_stubs): Exclude dynamic library
+	BFDs that have not been loaded.
+
 2019-11-19  Alan Modra  <amodra@gmail.com>
 
 	PR 25197
diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index f27ee421833..dca208f06aa 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -6527,8 +6527,11 @@ elf32_arm_size_stubs (bfd *output_bfd,
 	  asection *section;
 	  Elf_Internal_Sym *local_syms = NULL;
 
-	  if (!is_arm_elf (input_bfd)
-	      || (elf_dyn_lib_class (input_bfd) & DYN_AS_NEEDED) != 0)
+	  if (!is_arm_elf (input_bfd))
+	    continue;
+	  if ((input_bfd->flags & DYNAMIC) != 0
+	      && (elf_sym_hashes (input_bfd) == NULL
+		  || (elf_dyn_lib_class (input_bfd) & DYN_AS_NEEDED) != 0))
 	    continue;
 
 	  num_a8_relocs = 0;