commit 7f1eec317db79627b473c5b149a22a1b20d1f68f

Author: Mark Wielaard <mjw@redhat.com>

Date:   Wed Apr 9 11:33:23 2014 +0200

    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

@@ -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;