diff options
author | Neels Hofmeyr <neels@hofmeyr.de> | 2019-08-21 16:56:41 +0200 |
---|---|---|
committer | laforge <laforge@gnumonks.org> | 2019-08-29 05:42:02 +0000 |
commit | 2e8f881f7290fb4fcff9e42b4b80ffaeb227bb34 (patch) | |
tree | bbc6f108b7966293922a90aaaf1d3c1052a4e981 | |
parent | 85031ee0aa4457e8751b1b3800a2d75cf3fdd499 (diff) |
fix segfault: don't send CC REL on NULL msc_a
Apparently, if a conn disappears during an ongoing call, the CC code tried to
send a CC REL on a NULL msc_a during cleanup, which lead to a crash
(cccamp2019). Guard against that.
Crash:
#0 msc_a_tx_dtap_to_i (msc_a=0x0, dtap=0x55a4bf2fa0f0) at ../../../../src/osmo-msc/src/libmsc/msc_a.c:1565
#1 0x000055a4be1bb03c in trans_tx_gsm48 (trans=0x55a4bf2d52a0, trans=0x55a4bf2d52a0, trans=0x55a4bf2d52a0, msg=<optimized out>)
at ../../../../src/osmo-msc/src/libmsc/gsm_04_08_cc.c:82
#2 gsm48_cc_tx_release (trans=trans@entry=0x55a4bf2d52a0, arg=arg@entry=0x7ffdd731a0e0) at ../../../../src/osmo-msc/src/libmsc/gsm_04_08_cc.c:1101
#3 0x000055a4be1bee65 in _gsm48_cc_trans_free (trans=trans@entry=0x55a4bf2d52a0) at ../../../../src/osmo-msc/src/libmsc/gsm_04_08_cc.c:278
#4 0x000055a4be1ab654 in trans_free (trans=trans@entry=0x55a4bf2d52a0) at ../../../../src/osmo-msc/src/libmsc/transaction.c:170
#5 0x000055a4be1bd091 in mncc_tx_to_gsm_cc (net=<optimized out>, msg=msg@entry=0x55a4bf2d3b68)
at ../../../../src/osmo-msc/src/libmsc/gsm_04_08_cc.c:1971
#6 0x000055a4be1bf1e5 in mncc_tx_to_cc (net=<optimized out>, arg=arg@entry=0x55a4bf2d3b68)
at ../../../../src/osmo-msc/src/libmsc/gsm_04_08_cc.c:2049
#7 0x000055a4be18ed63 in mncc_sock_read (bfd=0x55a4bf2563b8, bfd=0x55a4bf2563b8) at ../../../../src/osmo-msc/src/libmsc/mncc_sock.c:121
#8 mncc_sock_cb (bfd=0x55a4bf2563b8, flags=1) at ../../../../src/osmo-msc/src/libmsc/mncc_sock.c:189
#9 0x00007fcfad607ce1 in osmo_fd_disp_fds (_eset=0x7ffdd731a9a0, _wset=0x7ffdd731a920, _rset=0x7ffdd731a8a0)
at ../../../src/libosmocore/src/select.c:223
#10 osmo_select_main (polling=<optimized out>) at ../../../src/libosmocore/src/select.c:263
#11 0x000055a4be17dd56 in main (argc=3, argv=<optimized out>) at ../../../../src/osmo-msc/src/osmo-msc/msc_main.c:723
Change-Id: Ia1bb0410ad0618c182a5f6da06af342b6d483eff
-rw-r--r-- | src/libmsc/gsm_04_08_cc.c | 12 | ||||
-rw-r--r-- | src/libmsc/msc_a.c | 9 |
2 files changed, 19 insertions, 2 deletions
diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c index a1fea9aa1..ba6a19738 100644 --- a/src/libmsc/gsm_04_08_cc.c +++ b/src/libmsc/gsm_04_08_cc.c @@ -1076,8 +1076,16 @@ static int gsm48_cc_rx_release(struct gsm_trans *trans, struct msgb *msg) static int gsm48_cc_tx_release(struct gsm_trans *trans, void *arg) { struct gsm_mncc *rel = arg; - struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 CC REL"); - struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + struct msgb *msg; + struct gsm48_hdr *gh; + + if (!trans->msc_a) { + LOG_TRANS(trans, LOGL_DEBUG, "Cannot send CC REL, there is no MSC-A connection\n"); + return -EINVAL; + } + + msg = gsm48_msgb_alloc_name("GSM 04.08 CC REL"); + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); gh->msg_type = GSM48_MT_CC_RELEASE; diff --git a/src/libmsc/msc_a.c b/src/libmsc/msc_a.c index 553761fe3..b3e2e32c3 100644 --- a/src/libmsc/msc_a.c +++ b/src/libmsc/msc_a.c @@ -1562,6 +1562,15 @@ int msc_a_tx_dtap_to_i(struct msc_a *msc_a, struct msgb *dtap) { struct ran_msg ran_msg; + if (!msc_a) { + struct gsm48_hdr *gh = msgb_l3(dtap) ? : dtap->data; + uint8_t pdisc = gsm48_hdr_pdisc(gh); + LOGP(DMSC, LOGL_ERROR, "Attempt to send DTAP to NULL MSC-A, dropping message: %s %s\n", + gsm48_pdisc_name(pdisc), gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh))); + msgb_free(dtap); + return -EIO; + } + if (msc_a->c.ran->type == OSMO_RAT_EUTRAN_SGS) { /* The SGs connection to the MME always is at the MSC-A. */ return sgs_iface_tx_dtap_ud(msc_a, dtap); |