Change in libosmo-sccp[master]: sccp: Fix null ptr access on malformed or unsupported msg received

[pespin]

pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmo-sccp/+/16895 )


Change subject: sccp: Fix null ptr access on malformed or unsupported msg received
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sccp: Fix null ptr access on malformed or unsupported msg received

Detected while running a TTCN3 sending malformed SCCP message in
SCCP_Tests_RAW.ttcn:

sccp_user.c:174:12: runtime error: member access within null pointer of type 'struct xua_msg'
ASAN:DEADLYSIGNAL
=================================================================
==6==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x7f2a11f93c5c bp 0x7ffefcf05c50 sp 0x7ffefcf05c10 T0)
    #0 0x7f2a11f93c5b in mtp_user_prim_cb /tmp/libosmo-sccp/src/sccp_user.c:174
    #1 0x7f2a11fb48f9 in deliver_to_mtp_user /tmp/libosmo-sccp/src/osmo_ss7_hmrt.c:94
    #2 0x7f2a11fb4c8a in hmdt_message_for_distribution /tmp/libosmo-sccp/src/osmo_ss7_hmrt.c:133
    #3 0x7f2a11fb5c90 in m3ua_hmdc_rx_from_l2 /tmp/libosmo-sccp/src/osmo_ss7_hmrt.c:275
    #4 0x7f2a11f6f5c2 in m3ua_rx_xfer /tmp/libosmo-sccp/src/m3ua.c:586
    #5 0x7f2a11f70480 in m3ua_rx_msg /tmp/libosmo-sccp/src/m3ua.c:739
    #6 0x7f2a11faee35 in xua_srv_conn_cb /tmp/libosmo-sccp/src/osmo_ss7.c:1623
    #7 0x7f2a0f46d082  (/usr/lib/x86_64-linux-gnu/libosmonetif.so.8+0xb082)
    #8 0x7f2a1186c0be  (/usr/lib/x86_64-linux-gnu/libosmocore.so.12+0xc0be)
    #9 0x7f2a1186c735 in osmo_select_main (/usr/lib/x86_64-linux-gnu/libosmocore.so.12+0xc735)
    #10 0x557378718219 in main /tmp/libosmo-sccp/examples/sccp_demo_user.c:264
    #11 0x7f2a105ad2e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #12 0x557378717059 in _start (/usr/local/bin/sccp_demo_user+0x6059)

Change-Id: Idafa8c9693d98ecd214b62155372e4db69e2a4a4
---
M src/sccp_user.c
1 file changed, 6 insertions(+), 0 deletions(-)



  git pull ssh://gerrit.osmocom.org:29418/libosmo-sccp refs/changes/95/16895/1

diff --git a/src/sccp_user.c b/src/sccp_user.c
index 9df5817..386f424 100644
--- a/src/sccp_user.c
+++ b/src/sccp_user.c
@@ -171,6 +171,12 @@
 	case OSMO_PRIM(OSMO_MTP_PRIM_TRANSFER, PRIM_OP_INDICATION):
 		/* Convert from SCCP to SUA in xua_msg format */
 		xua = osmo_sccp_to_xua(oph->msg);
+		if (!xua) {
+			LOGP(DLSCCP, LOGL_ERROR, "Couldn't convert SCCP to SUA: %s\n",
+				msgb_hexdump(oph->msg));
+			rc = -1;
+			break;
+		}
 		xua->mtp = omp->u.transfer;
 		/* hand this primitive into SCCP via the SCRC code */
 		rc = scrc_rx_mtp_xfer_ind_xua(inst, xua);

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Gerrit-Project: libosmo-sccp
Gerrit-Branch: master
Gerrit-Change-Id: Idafa8c9693d98ecd214b62155372e4db69e2a4a4
Gerrit-Change-Number: 16895
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pespin at sysmocom.de>
Gerrit-MessageType: newchange
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