binutils: CVE-2017-8396

Source: git://sourceware.org/git/binutils-gdb.git
MR: 74101
Type: Security Fix
Disposition: Backport from binutils-2_29
ChangeID: db47540066f83529439566f8621d6e35fe86b77c
Description:

buffer overflow in perform_relocation

The existing reloc offset range tests didn't catch small negative
offsets less than the size of the reloc field.

PR 21432
 * reloc.c (reloc_offset_in_range): New function.
   (bfd_perform_relocation, bfd_install_relocation): Use it.
   (_bfd_final_link_relocate): Likewise.

Affects: <= 2.29
Author: Alan Modra <amodra@gmail.com>
Signed-off-by: Thiruvadi Rajaraman <trajaraman@mvista.com>
Reviewed-by: Armin Kuster <akuster@mvista.com>
Signed-off-by: Armin Kuster <akuster@mvista.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

2 files changed, 103 insertions, 0 deletions

diff --git a/meta/recipes-devtools/binutils/binutils-2.27.inc b/meta/recipes-devtools/binutils/binutils-2.27.inc
index 23aac6bd5e..014655f7df 100644
--- a/meta/recipes-devtools/binutils/binutils-2.27.inc
+++ b/meta/recipes-devtools/binutils/binutils-2.27.inc
@@ -71,6 +71,7 @@ SRC_URI = "\
      file://CVE-2017-8395.patch \
      file://CVE-2017-8397.patch \
      file://CVE-2017-7300.patch \
+     file://CVE-2017-8396.patch \
 "
 S  = "${WORKDIR}/git"
 
diff --git a/meta/recipes-devtools/binutils/binutils/CVE-2017-8396.patch b/meta/recipes-devtools/binutils/binutils/CVE-2017-8396.patch
new file mode 100644
index 0000000000..b1bf92f4dd
--- /dev/null
+++ b/meta/recipes-devtools/binutils/binutils/CVE-2017-8396.patch
@@ -0,0 +1,102 @@
+commit a941291cab71b9ac356e1c03968c177c03e602ab
+Author: Alan Modra <amodra@gmail.com>
+Date:   Sat Apr 29 14:48:16 2017 +0930
+
+    PR21432, buffer overflow in perform_relocation
+    
+    The existing reloc offset range tests didn't catch small negative
+    offsets less than the size of the reloc field.
+    
+    	PR 21432
+    	* reloc.c (reloc_offset_in_range): New function.
+    	(bfd_perform_relocation, bfd_install_relocation): Use it.
+    	(_bfd_final_link_relocate): Likewise.
+
+Upstream-Status: Backport
+
+CVE: CVE-2017-8396
+Signed-off-by: Thiruvadi Rajaraman <trajaraman@mvista.com>
+
+Index: git/bfd/reloc.c
+===================================================================
+--- git.orig/bfd/reloc.c	2017-09-05 18:12:07.448886623 +0530
++++ git/bfd/reloc.c	2017-09-05 18:12:07.564887511 +0530
+@@ -538,6 +538,22 @@
+   return flag;
+ }
+ 
++/* HOWTO describes a relocation, at offset OCTET.  Return whether the
++   relocation field is within SECTION of ABFD.  */
++
++static bfd_boolean
++reloc_offset_in_range (reloc_howto_type *howto, bfd *abfd,
++		       asection *section, bfd_size_type octet)
++{
++  bfd_size_type octet_end = bfd_get_section_limit_octets (abfd, section);
++  bfd_size_type reloc_size = bfd_get_reloc_size (howto);
++
++  /* The reloc field must be contained entirely within the section.
++     Allow zero length fields (marker relocs or NONE relocs where no
++     relocation will be performed) at the end of the section.  */
++  return octet <= octet_end && octet + reloc_size <= octet_end;
++}
++
+ /*
+ FUNCTION
+ 	bfd_perform_relocation
+@@ -618,15 +634,9 @@
+ 	return cont;
+     }
+ 
+-  /* Is the address of the relocation really within the section?
+-     Include the size of the reloc in the test for out of range addresses.
+-     PR 17512: file: c146ab8b, 46dff27f, 38e53ebf.  */
++  /* Is the address of the relocation really within the section?  */
+   octets = reloc_entry->address * bfd_octets_per_byte (abfd);
+-  if (octets + bfd_get_reloc_size (howto)
+-      > bfd_get_section_limit_octets (abfd, input_section)
+-      /* Check for an overly large offset which
+-	 masquerades as a negative value too.  */
+-      || (octets + bfd_get_reloc_size (howto) < bfd_get_reloc_size (howto)))
++  if (!reloc_offset_in_range (howto, abfd, input_section, octets))
+     return bfd_reloc_outofrange;
+ 
+   /* Work out which section the relocation is targeted at and the
+@@ -1010,8 +1020,7 @@
+ 
+   /* Is the address of the relocation really within the section?  */
+   octets = reloc_entry->address * bfd_octets_per_byte (abfd);
+-  if (octets + bfd_get_reloc_size (howto)
+-      > bfd_get_section_limit_octets (abfd, input_section))
++  if (!reloc_offset_in_range (howto, abfd, input_section, octets))
+     return bfd_reloc_outofrange;
+ 
+   /* Work out which section the relocation is targeted at and the
+@@ -1349,8 +1358,7 @@
+   bfd_size_type octets = address * bfd_octets_per_byte (input_bfd);
+ 
+   /* Sanity check the address.  */
+-  if (octets + bfd_get_reloc_size (howto)
+-      > bfd_get_section_limit_octets (input_bfd, input_section))
++  if (!reloc_offset_in_range (howto, input_bfd, input_section, octets))
+     return bfd_reloc_outofrange;
+ 
+   /* This function assumes that we are dealing with a basic relocation
+Index: git/bfd/ChangeLog
+===================================================================
+--- git.orig/bfd/ChangeLog	2017-09-05 18:12:07.448886623 +0530
++++ git/bfd/ChangeLog	2017-09-05 18:13:46.745645897 +0530
+@@ -73,6 +73,13 @@
+        (evax_bfd_print_egsd): Check for an overlarge record length.
+        (evax_bfd_print_etir): Likewise.
+ 
++2017-04-29  Alan Modra  <amodra@gmail.com>
++
++       PR 21432
++       * reloc.c (reloc_offset_in_range): New function.
++       (bfd_perform_relocation, bfd_install_relocation): Use it.
++       (_bfd_final_link_relocate): Likewise.
++
+ 2017-04-26  Nick Clifton  <nickc@redhat.com>
+ 
+        PR binutils/21434