#89 global-buffer-overflow in arrow_path at gensvg.c:1082

[Suhwan Song]

Hi,
I found a global-buffer-overflow in arrow_path at gensvg.c:1082

fig2dev Version 3.2.7b
commit ca48ccc90bd3e7801a63cf9a541f292b28ed1260

Please run following command to reproduce it,

fig2dev -L svg $PoC

ASAN LOG

==45947==ERROR: AddressSanitizer: global-buffer-overflow on address 0x000001903b98 at pc 0x0000008be954 bp 0x7ffdf7a01100 sp 0x7ffdf7a010f8
READ of size 4 at 0x000001903b98 thread T0
    #0 0x8be953 in arrow_path /home/tmp/mcj-fig2dev/fig2dev/dev/gensvg.c:1082:40
    #1 0x8accb8 in svg_arrows /home/tmp/mcj-fig2dev/fig2dev/dev/gensvg.c:1174:2
    #2 0x8b38a0 in gensvg_arc /home/tmp/mcj-fig2dev/fig2dev/dev/gensvg.c:907:9
    #3 0x549d5b in gendev_objects /home/tmp/mcj-fig2dev/fig2dev/fig2dev.c:1007:6
    #4 0x549d5b in main /home/tmp/mcj-fig2dev/fig2dev/fig2dev.c:484
    #5 0x7f012ef65b96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
    #6 0x41b469 in _start (/home/tmp/fig2dev+0x41b469)

0x000001903b98 is located 8 bytes to the left of global variable 'fpoints' defined in 'gensvg.c:1130:18' (0x1903ba0) of size 400
0x000001903b98 is located 52 bytes to the right of global variable 'bnclippoints' defined in 'gensvg.c:1129:41' (0x1903b60) of size 4
SUMMARY: AddressSanitizer: global-buffer-overflow /home/tmp/mcj-fig2dev/fig2dev/dev/gensvg.c:1082:40 in arrow_path
Shadow bytes around the buggy address:
  0x000080318720: 01 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
  0x000080318730: 01 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
  0x000080318740: 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9
  0x000080318750: f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9
  0x000080318760: f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9
=>0x000080318770: f9 f9 f9[f9]00 00 00 00 00 00 00 00 00 00 00 00
  0x000080318780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080318790: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0000803187a0: 00 00 00 00 00 00 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
  0x0000803187b0: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
  0x0000803187c0: 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
==45947==ABORTING

[tkl]

Fixed with commit [c72ffd].