mpg123: global buffer overflow in III_i_stereo (layer3.c)

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

Description:
mpg123 is a fast console MPEG Audio Player and decoder library.

The complete ASan output of the issue:

# mpg123-mpg123 -t $FILE
==10588==ERROR: AddressSanitizer: global-buffer-overflow on address 0x7f01025c5cbc at pc 0x7f010229bfe3 bp 
0x7ffc988ac5b0 sp 0x7ffc988ac5a8
READ of size 4 at 0x7f01025c5cbc thread T0
    #0 0x7f010229bfe2 in III_i_stereo 
/var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/libmpg123/layer3.c:1343:10
    #1 0x7f010229bfe2 in INT123_do_layer3 
/var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/libmpg123/layer3.c:2013
    #2 0x7f01021d3708 in decode_the_frame 
/var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/libmpg123/libmpg123.c:710:14
    #3 0x7f01021dc61d in mpg123_decode_frame 
/var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/libmpg123/libmpg123.c:849:4
    #4 0x535783 in play_frame /var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/mpg123.c:739:7
    #5 0x53a3a7 in main /var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/mpg123.c:1363:8
    #6 0x7f0100f1d680 in __libc_start_main 
/tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289
    #7 0x41bec8 in mpg123_seek_frame (/usr/bin/mpg123-mpg123+0x41bec8)

0x7f01025c5cbc is located 4 bytes to the left of global variable 'pow2_1' defined in 
'/var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/libmpg123/layer3.c:50:27' (0x7f01025c5cc0) of size 
128
0x7f01025c5cbc is located 28 bytes to the right of global variable 'pow1_1' defined in 
'/var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/libmpg123/layer3.c:50:13' (0x7f01025c5c20) of 
size 128
SUMMARY: AddressSanitizer: global-buffer-overflow 
/var/tmp/portage/media-sound/mpg123-1.25.0/work/mpg123-1.25.0/src/libmpg123/layer3.c:1343:10 in III_i_stereo
Shadow bytes around the buggy address:
  0x0fe0a04b0b40: f9 f9 f9 f9 00 04 f9 f9 f9 f9 f9 f9 00 04 f9 f9
  0x0fe0a04b0b50: f9 f9 f9 f9 00 00 00 00 00 00 00 00 f9 f9 f9 f9
  0x0fe0a04b0b60: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
  0x0fe0a04b0b70: 00 00 00 00 f9 f9 f9 f9 00 00 00 00 00 00 00 00
  0x0fe0a04b0b80: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0fe0a04b0b90: 00 00 00 00 f9 f9 f9[f9]00 00 00 00 00 00 00 00
  0x0fe0a04b0ba0: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
  0x0fe0a04b0bb0: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9
  0x0fe0a04b0bc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0fe0a04b0bd0: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
  0x0fe0a04b0be0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==10588==ABORTING
Affected version:
1.25.0

Fixed version:
N/A

Commit fix:
N/A

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

CVE:
CVE-2017-11126

Reproducer:
https://github.com/asarubbo/poc/blob/master/00300-mpg123-globaloverflow-III_i_stereo

Timeline:
2017-06-30: bug discovered and reported to upstream
2017-07-03: blog post about the issue
2017-07-10: CVE assigned

Note:
This bug was found with American Fuzzy Lop.

Permalink:
https://blogs.gentoo.org/ago/2017/07/03/mpg123-global-buffer-overflow-in-iii_i_stereo-layer3-c/

--
Agostino Sarubbo
Gentoo Linux Developer