From: Mark Wielaard <mjw@redhat.com>
Subject: Check for overflow before calling malloc to uncompress data.
Date: Wed Apr 9 11:33:23 2014 +0200
Git-commit: 7f1eec317db79627b473c5b149a22a1b20d1f68f
References: CVE-2014-0172, bnc#872785
Signed-off-by: Tony Jones <tonyj@suse.de>

    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/dwarf_begin_elf.c b/libdw/dwarf_begin_elf.c
index 79daeac..34ea373 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;