From: Alan Modra <amodra@gmail.com>
Date: Fri, 21 Jun 2019 02:21:38 +0000 (+0930)
Subject: PR24689, string table corruption
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=890f750a3b053532a4b839a2dd6243076de12031;p=binutils-gdb.git

PR24689, string table corruption

The testcase in the PR had a e_shstrndx section of type SHT_GROUP.
hdr->contents were initialized by setup_group rather than being read
from the file, thus last byte was not zero and string dereference ran
off the end of the buffer.

	PR 24689
	* elfcode.h (elf_object_p): Check type of e_shstrndx section.
---

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index f40f6ed63dc..bc7671e9ea3 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2019-06-21  Alan Modra  <amodra@gmail.com>
+
+	PR 24689
+	* elfcode.h (elf_object_p): Check type of e_shstrndx section.
+
 2019-06-19  Alan Modra  <amodra@gmail.com>
 
 	PR 24697
diff --git a/bfd/elfcode.h b/bfd/elfcode.h
index a0487b0843c..5180f79a74d 100644
--- a/bfd/elfcode.h
+++ b/bfd/elfcode.h
@@ -754,7 +754,8 @@ elf_object_p (bfd *abfd)
   /* A further sanity check.  */
   if (i_ehdrp->e_shnum != 0)
     {
-      if (i_ehdrp->e_shstrndx >= elf_numsections (abfd))
+      if (i_ehdrp->e_shstrndx >= elf_numsections (abfd)
+	  || i_shdrp[i_ehdrp->e_shstrndx].sh_type != SHT_STRTAB)
 	{
 	  /* PR 2257:
 	     We used to just goto got_wrong_format_error here