Invalid write in gw_str_xor

==31899==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffd556a96a4 at pc 0x7f92af9d29cd bp 0x7ffd556a9540 sp 0x7ffd556a9530

WRITE of size 1 at 0x7ffd556a96a4 thread T0

    #0 0x7f92af9d29cc in gw_str_xor /home/markusjm/MaxScale/server/core/utils.c:227

    #1 0x7f92a5456313 in load_hashed_password /home/markusjm/MaxScale/server/modules/protocol/MySQL/mysql_common.c:1231

    #2 0x7f92a5457030 in gw_send_backend_auth /home/markusjm/MaxScale/server/modules/protocol/MySQL/mysql_common.c:1393

    #3 0x7f92a4803948 in gw_read_backend_event /home/markusjm/MaxScale/server/modules/protocol/MySQL/MySQLBackend/mysql_backend.c:485

    #4 0x7f92af9b4f01 in process_pollq /home/markusjm/MaxScale/server/core/poll.c:999

    #5 0x7f92af9b3cd6 in poll_waitevents /home/markusjm/MaxScale/server/core/poll.c:777

    #6 0x40a66c in main /home/markusjm/MaxScale/server/core/gateway.cc:2035

    #7 0x7f92ad8cc400 in __libc_start_main (/lib64/libc.so.6+0x20400)

    #8 0x404469 in _start (/home/markusjm/build/bin/maxscale+0x404469)

Address 0x7ffd556a96a4 is located in stack of thread T0 at offset 244 in frame

    #0 0x7f92a54560ee in load_hashed_password /home/markusjm/MaxScale/server/modules/protocol/MySQL/mysql_common.c:1215

  This frame has 4 object(s):

    [32, 52) 'hash1'

    [96, 116) 'hash2'

    [160, 180) 'new_sha'

    [224, 244) 'client_scramble' <== Memory access at offset 244 overflows this variable

HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext

      (longjmp and C++ exceptions *are* supported)

SUMMARY: AddressSanitizer: stack-buffer-overflow /home/markusjm/MaxScale/server/core/utils.c:227 in gw_str_xor

Shadow bytes around the buggy address:

  0x10002aacd280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

  0x10002aacd290: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

  0x10002aacd2a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

  0x10002aacd2b0: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 04 f4 f2 f2

  0x10002aacd2c0: f2 f2 00 00 04 f4 f2 f2 f2 f2 00 00 04 f4 f2 f2

=>0x10002aacd2d0: f2 f2 00 00[04]f4 00 00 00 00 00 00 00 00 00 00

  0x10002aacd2e0: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f4

  0x10002aacd2f0: f4 f4 f2 f2 f2 f2 00 00 00 00 00 00 00 00 00 00

  0x10002aacd300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

  0x10002aacd310: 00 00 00 00 00 00 00 00 00 00 00 00 f4 f4 00 00

  0x10002aacd320: 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

  Heap right redzone:      fb

  Freed heap region:       fd

  Stack left redzone:      f1

  Stack mid redzone:       f2

  Stack right redzone:     f3

  Stack partial redzone:   f4

  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

==31899==ABORTING