tree 8ed2739b0da1d8e8f3a07523ed7356bd5616f26d
parent cb360f06c84f311924465ff8371798e1ece3c249
author Neels Hofmeyr <neels@hofmeyr.de> 1525442564 +0200
committer Neels Hofmeyr <neels@hofmeyr.de> 1525442566 +0200

fix luop crash: use buffer for APN that remains valid

In osmo_gsup_configure_wildcard_apn(), do not compose APN into a local buffer
that becomes invalid as soon as the function exits. Instead, use a caller
provided buf.

Fixes OS#3231 crash:

  ==20030==ERROR: AddressSanitizer: stack-buffer-underflow on address 0x7fffffffd9c0 at pc 0x7ffff6e9b6c2 bp 0x7fffffffd900 sp 0x7fffffffd0b0
  READ of size 2 at 0x7fffffffd9c0 thread T0
      #0 0x7ffff6e9b6c1  (/usr/lib/x86_64-linux-gnu/libasan.so.4+0x766c1)
      #1 0x7ffff6314419 in tlv_put ../../../../src/libosmocore/include/osmocom/gsm/tlv.h:107
      #2 0x7ffff6314419 in msgb_tlv_put ../../../../src/libosmocore/include/osmocom/gsm/tlv.h:299
      #3 0x7ffff6314419 in encode_pdp_info ../../../../src/libosmocore/src/gsm/gsup.c:419
      #4 0x7ffff6314419 in osmo_gsup_encode ../../../../src/libosmocore/src/gsm/gsup.c:535
      #5 0x555555580016 in _luop_tx_gsup ../../../src/osmo-hlr/src/luop.c:54
      #6 0x5555555809d8 in lu_op_tx_insert_subscr_data ../../../src/osmo-hlr/src/luop.c:264
      #7 0x55555558b356 in rx_upd_loc_req ../../../src/osmo-hlr/src/hlr.c:306
      #8 0x55555558b356 in read_cb ../../../src/osmo-hlr/src/hlr.c:365
      #9 0x555555586671 in osmo_gsup_server_read_cb ../../../src/osmo-hlr/src/gsup_server.c:105
      #10 0x7ffff5b35911 in ipa_server_conn_read ../../../src/libosmo-abis/src/input/ipa.c:356
      #11 0x7ffff5b35911 in ipa_server_conn_cb ../../../src/libosmo-abis/src/input/ipa.c:387
      #12 0x7ffff5e5541f in osmo_fd_disp_fds ../../../src/libosmocore/src/select.c:216
      #13 0x7ffff5e5541f in osmo_select_main ../../../src/libosmocore/src/select.c:256
      #14 0x5555555791b6 in main ../../../src/osmo-hlr/src/hlr.c:600
      #15 0x7ffff4707a86 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21a86)
      #16 0x555555579679 in _start (/usr/local/bin/osmo-hlr+0x25679)

  Address 0x7fffffffd9c0 is located in stack of thread T0 at offset 16 in frame
      #0 0x7ffff63131ff in osmo_gsup_encode ../../../../src/libosmocore/src/gsm/gsup.c:481

    This frame has 1 object(s):
      [32, 64) 'bcd_buf' <== Memory access at offset 16 underflows this variable

Related: OS#3231
Change-Id: I83d9ef2868bbb01e3f1ddb7920fe735aca172b15