From: Mark Wielaard <mjw@redhat.com>
Date: Wed, 9 Apr 2014 09:33:23 +0000 (+0200)
Subject: CVE-2014-0172 Check for overflow before calling malloc to uncompress data.
X-Git-Tag: elfutils-0.159~24
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7f1eec317db79627b473c5b149a22a1b20d1f68f;p=thirdparty%2Felfutils.git

CVE-2014-0172 Check for overflow before calling malloc to uncompress data.

https://bugzilla.redhat.com/show_bug.cgi?id=1085663

Reported-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Mark Wielaard <mjw@redhat.com>
---

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 1d9b9a3b1..e8f0eb88a 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2014-04-09  Mark Wielaard  <mjw@redhat.com>
+
+	* dwarf_begin_elf.c (check_section): Check for unsigned overflow
+	before calling malloc to uncompress data.
+
 2014-03-03  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	Fix abort() on missing section headers.
diff --git a/libdw/dwarf_begin_elf.c b/libdw/dwarf_begin_elf.c
index 79daeacb6..34ea37344 100644
--- a/libdw/dwarf_begin_elf.c
+++ b/libdw/dwarf_begin_elf.c
@@ -1,5 +1,5 @@
 /* Create descriptor from ELF descriptor for processing file.
-   Copyright (C) 2002-2011 Red Hat, Inc.
+   Copyright (C) 2002-2011, 2014 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -282,6 +282,12 @@ check_section (Dwarf *result, GElf_Ehdr *ehdr, Elf_Scn *scn, bool inscngrp)
 	    memcpy (&size, data->d_buf + 4, sizeof size);
 	    size = be64toh (size);
 
+	    /* Check for unsigned overflow so malloc always allocated
+	       enough memory for both the Elf_Data header and the
+	       uncompressed section data.  */
+	    if (unlikely (sizeof (Elf_Data) + size < size))
+	      break;
+
 	    Elf_Data *zdata = malloc (sizeof (Elf_Data) + size);
 	    if (unlikely (zdata == NULL))
 	      break;