binutils: NULL pointer dereference in bfd_hash_hash (hash.c)

["Agostino Sarubbo" <ago () gentoo org>]

Description:
binutils is a set of tools necessary to build programs.

The stacktrace of this issue appears to be a NULL pointer access. However the upstream maintainer changed the summary 
of the bugreport to “DW_AT_name with out of bounds reference”. The commit also 
reference to “DW_AT_name with out of bounds reference”

The complete ASan output of the issue:

# nm -A -a -l -S -s --special-syms --synthetic --with-symbol-versions -D $FILE
==8739==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x00000053bf16 bp 0x7ffcab59ee60 sp 
0x7ffcab59ee20 T0)
==8739==The signal is caused by a READ memory access.
==8739==Hint: address points to the zero page.
    #0 0x53bf15 in bfd_hash_hash /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/hash.c:441:15
    #1 0x53bf15 in bfd_hash_lookup /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/hash.c:467
    #2 0x6a2049 in insert_info_hash_table /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:487:37
    #3 0x6a2049 in comp_unit_hash_info /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:3776
    #4 0x6a2049 in stash_maybe_update_info_hash_tables 
/var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:4120
    #5 0x69cbbc in stash_maybe_enable_info_hash_tables 
/var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:4214:3
    #6 0x69cbbc in _bfd_dwarf2_find_nearest_line 
/var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:4613
    #7 0x5f330e in _bfd_elf_find_line /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/elf.c:8695:10
    #8 0x5176a3 in print_symbol /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1003:9
    #9 0x514e4d in print_symbols /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1084:7
    #10 0x514e4d in display_rel_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1200
    #11 0x510976 in display_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1318:7
    #12 0x50f4ce in main /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1792:12
    #13 0x7fd148c7b680 in __libc_start_main 
/var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289
    #14 0x41a638 in chmod (/usr/x86_64-pc-linux-gnu/binutils-bin/git/nm+0x41a638)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/hash.c:441:15 in 
bfd_hash_hash
==8739==ABORTING

Affected version:
2.29.51.20170924 and maybe past releases

Fixed version:
N/A

Commit fix:
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=11855d8a1f11b102a702ab76e95b22082cccf2f8

Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.

CVE:
CVE-2017-15022

Reproducer:
https://github.com/asarubbo/poc/blob/master/00375-binutils-NULLptr-bfd_hash_hash

Timeline:
2017-09-25: bug discovered and reported to upstream
2017-09-25: upstream released a patch
2017-10-03: blog post about the issue
2017-10-04: CVE assigned

Note:
This bug was found with American Fuzzy Lop.
This bug was identified with bare metal servers donated by Packet. This work is also supported by the Core
Infrastructure Initiative.

Permalink:
https://blogs.gentoo.org/ago/2017/10/03/binutils-null-pointer-dereference-in-bfd_hash_hash-hash-c/

--
Agostino Sarubbo
Gentoo Linux Developer