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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
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