From: Mark Wielaard <mjw@redhat.com>
Date: Sun, 16 Nov 2014 23:42:53 +0000 (+0100)
Subject: libelf: elf_getshdrstrndx cannot use SHN_XINDEX without section headers.
X-Git-Tag: elfutils-0.161~82
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=babcdeff28bdf1d5ce26c8aa35fea420921f4ba7;p=thirdparty%2Felfutils.git

libelf: elf_getshdrstrndx cannot use SHN_XINDEX without section headers.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
---

diff --git a/libelf/ChangeLog b/libelf/ChangeLog
index ef5da43d4..633a8923f 100644
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -1,3 +1,8 @@
+2014-11-16  Mark Wielaard  <mjw@redhat.com>
+
+	* elf_getshdrstrndx.c: Check there are section headers before
+	handling SHN_XINDEX.
+
 2014-11-16  Mark Wielaard  <mjw@redhat.com>
 
 	* elf32_getphdr.c (getphdr_wrlock): Check e_phoff isn't zero.
diff --git a/libelf/elf_getshdrstrndx.c b/libelf/elf_getshdrstrndx.c
index 1dbed4c84..6f8d66e80 100644
--- a/libelf/elf_getshdrstrndx.c
+++ b/libelf/elf_getshdrstrndx.c
@@ -92,6 +92,13 @@ elf_getshdrstrndx (elf, dst)
 	  if (elf->class == ELFCLASS32)
 	    {
 	      size_t offset;
+	      if (unlikely (elf->state.elf32.scns.cnt == 0))
+		{
+		  /* Cannot use SHN_XINDEX without section headers.  */
+		  __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER);
+		  result = -1;
+		  goto out;
+		}
 
 	      if (elf->state.elf32.scns.data[0].shdr.e32 != NULL)
 		{
@@ -146,6 +153,14 @@ elf_getshdrstrndx (elf, dst)
 	    }
 	  else
 	    {
+	      if (unlikely (elf->state.elf64.scns.cnt == 0))
+		{
+		  /* Cannot use SHN_XINDEX without section headers.  */
+		  __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER);
+		  result = -1;
+		  goto out;
+		}
+
 	      if (elf->state.elf64.scns.data[0].shdr.e64 != NULL)
 		{
 		  num = elf->state.elf64.scns.data[0].shdr.e64->sh_link;