[SCTP]: Re-order SCTP initializations to avoid race with sctp_rcv()

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>

[SCTP]: Re-order SCTP initializations to avoid race with sctp_rcv()
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sridhar Samudrala · David S. Miller
1 parent ce5325c133
Showing 3 changed files with 79 additions and 53 deletions Side-by-side Diff
include/net/sctp/sctp.h
net/sctp/ipv6.c
net/sctp/protocol.c
@@ -378,11 +378,15 @@
  
 int sctp_v6_init(void);
 void sctp_v6_exit(void);
+int sctp_v6_add_protocol(void);
+void sctp_v6_del_protocol(void);
  
 #else /* #ifdef defined(CONFIG_IPV6) */
  
 static inline int sctp_v6_init(void) { return 0; }
 static inline void sctp_v6_exit(void) { return; }
+static inline int sctp_v6_add_protocol(void) { return 0; }
+static inline void sctp_v6_del_protocol(void) { return; }
  
 #endif /* #if defined(CONFIG_IPV6) */
  
@@ -992,46 +992,53 @@
 	.af            = &sctp_ipv6_specific,
 };
  
-/* Initialize IPv6 support and register with inet6 stack.  */
+/* Initialize IPv6 support and register with socket layer.  */
 int sctp_v6_init(void)
 {
-	int rc = proto_register(&sctpv6_prot, 1);
+	int rc;
  
+	/* Register the SCTP specific PF_INET6 functions. */
+	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
+
+	/* Register the SCTP specific AF_INET6 functions. */
+	sctp_register_af(&sctp_ipv6_specific);
+
+	rc = proto_register(&sctpv6_prot, 1);
 	if (rc)
-		goto out;
-	/* Register inet6 protocol. */
-	rc = -EAGAIN;
-	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
-		goto out_unregister_sctp_proto;
+		return rc;
  
 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
 	inet6_register_protosw(&sctpv6_stream_protosw);
  
-	/* Register the SCTP specific PF_INET6 functions. */
-	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
+	return 0;
+}
  
-	/* Register the SCTP specific AF_INET6 functions. */
-	sctp_register_af(&sctp_ipv6_specific);
-
+/* Register with inet6 layer. */
+int sctp_v6_add_protocol(void)
+{
 	/* Register notifier for inet6 address additions/deletions. */
 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
-	rc = 0;
-out:
-	return rc;
-out_unregister_sctp_proto:
-	proto_unregister(&sctpv6_prot);
-	goto out;
+
+	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
+		return -EAGAIN;
+
+	return 0;
 }
  
 /* IPv6 specific exit support. */
 void sctp_v6_exit(void)
 {
-	list_del(&sctp_ipv6_specific.list);
-	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
 	inet6_unregister_protosw(&sctpv6_stream_protosw);
-	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
 	proto_unregister(&sctpv6_prot);
+	list_del(&sctp_ipv6_specific.list);
+}
+
+/* Unregister with inet6 layer. */
+void sctp_v6_del_protocol(void)
+{
+	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
+	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
 }
@@ -975,28 +975,14 @@
 	if (!sctp_sanity_check())
 		goto out;
  
-	status = proto_register(&sctp_prot, 1);
-	if (status)
-		goto out;
-
-	/* Add SCTP to inet_protos hash table.  */
-	status = -EAGAIN;
-	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
-		goto err_add_protocol;
-
-	/* Add SCTP(TCP and UDP style) to inetsw linked list.  */
-	inet_register_protosw(&sctp_seqpacket_protosw);
-	inet_register_protosw(&sctp_stream_protosw);
-
-	/* Allocate a cache pools. */
+	/* Allocate bind_bucket and chunk caches. */
 	status = -ENOBUFS;
 	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
 					       sizeof(struct sctp_bind_bucket),
 					       0, SLAB_HWCACHE_ALIGN,
 					       NULL, NULL);
-
 	if (!sctp_bucket_cachep)
-		goto err_bucket_cachep;
+		goto out;
  
 	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
 					       sizeof(struct sctp_chunk),
@@ -1153,6 +1139,14 @@
 	INIT_LIST_HEAD(&sctp_address_families);
 	sctp_register_af(&sctp_ipv4_specific);
  
+	status = proto_register(&sctp_prot, 1);
+	if (status)
+		goto err_proto_register;
+
+	/* Register SCTP(UDP and TCP style) with socket layer.  */
+	inet_register_protosw(&sctp_seqpacket_protosw);
+	inet_register_protosw(&sctp_stream_protosw);
+
 	status = sctp_v6_init();
 	if (status)
 		goto err_v6_init;
  
  
  
@@ -1166,19 +1160,39 @@
  
 	/* Initialize the local address list. */
 	INIT_LIST_HEAD(&sctp_local_addr_list);
-
 	sctp_get_local_addr_list();
  
 	/* Register notifier for inet address additions/deletions. */
 	register_inetaddr_notifier(&sctp_inetaddr_notifier);
  
+	/* Register SCTP with inet layer.  */
+	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0) {
+		status = -EAGAIN;
+		goto err_add_protocol;
+	}
+
+	/* Register SCTP with inet6 layer.  */
+	status = sctp_v6_add_protocol();
+	if (status)
+		goto err_v6_add_protocol;
+
 	__unsafe(THIS_MODULE);
 	status = 0;
 out:
 	return status;
+err_v6_add_protocol:
+	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
+	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
+err_add_protocol:
+	sctp_free_local_addr_list();
+	sock_release(sctp_ctl_socket);
 err_ctl_sock_init:
 	sctp_v6_exit();
 err_v6_init:
+	inet_unregister_protosw(&sctp_stream_protosw);
+	inet_unregister_protosw(&sctp_seqpacket_protosw);
+	proto_unregister(&sctp_prot);
+err_proto_register:
 	sctp_sysctl_unregister();
 	list_del(&sctp_ipv4_specific.list);
 	free_pages((unsigned long)sctp_port_hashtable,
  
  
@@ -1192,19 +1206,13 @@
 			     sizeof(struct sctp_hashbucket)));
 err_ahash_alloc:
 	sctp_dbg_objcnt_exit();
-err_init_proc:
 	sctp_proc_exit();
+err_init_proc:
 	cleanup_sctp_mibs();
 err_init_mibs:
 	kmem_cache_destroy(sctp_chunk_cachep);
 err_chunk_cachep:
 	kmem_cache_destroy(sctp_bucket_cachep);
-err_bucket_cachep:
-	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
-	inet_unregister_protosw(&sctp_seqpacket_protosw);
-	inet_unregister_protosw(&sctp_stream_protosw);
-err_add_protocol:
-	proto_unregister(&sctp_prot);
 	goto out;
 }
  
@@ -1215,8 +1223,9 @@
 	 * up all the remaining associations and all that memory.
 	 */
  
-	/* Unregister notifier for inet address additions/deletions. */
-	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
+	/* Unregister with inet6/inet layers. */
+	sctp_v6_del_protocol();
+	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
  
 	/* Free the local address list.  */
 	sctp_free_local_addr_list();
  
@@ -1224,7 +1233,16 @@
 	/* Free the control endpoint.  */
 	sock_release(sctp_ctl_socket);
  
+	/* Cleanup v6 initializations. */
 	sctp_v6_exit();
+
+	/* Unregister with socket layer. */
+	inet_unregister_protosw(&sctp_stream_protosw);
+	inet_unregister_protosw(&sctp_seqpacket_protosw);
+
+	/* Unregister notifier for inet address additions/deletions. */
+	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
+
 	sctp_sysctl_unregister();
 	list_del(&sctp_ipv4_specific.list);
  
  
@@ -1236,16 +1254,13 @@
 		   get_order(sctp_port_hashsize *
 			     sizeof(struct sctp_bind_hashbucket)));
  
-	kmem_cache_destroy(sctp_chunk_cachep);
-	kmem_cache_destroy(sctp_bucket_cachep);
-
 	sctp_dbg_objcnt_exit();
 	sctp_proc_exit();
 	cleanup_sctp_mibs();
  
-	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
-	inet_unregister_protosw(&sctp_seqpacket_protosw);
-	inet_unregister_protosw(&sctp_stream_protosw);
+	kmem_cache_destroy(sctp_chunk_cachep);
+	kmem_cache_destroy(sctp_bucket_cachep);
+
 	proto_unregister(&sctp_prot);
 }
...	...	@@ -378,11 +378,15 @@
378	378
379	379	int sctp_v6_init(void);
380	380	void sctp_v6_exit(void);
	381	+int sctp_v6_add_protocol(void);
	382	+void sctp_v6_del_protocol(void);
381	383
382	384	#else /* #ifdef defined(CONFIG_IPV6) */
383	385
384	386	static inline int sctp_v6_init(void) { return 0; }
385	387	static inline void sctp_v6_exit(void) { return; }
	388	+static inline int sctp_v6_add_protocol(void) { return 0; }
	389	+static inline void sctp_v6_del_protocol(void) { return; }
386	390
387	391	#endif /* #if defined(CONFIG_IPV6) */
388	392
...	...	@@ -992,46 +992,53 @@
992	992	.af = &sctp_ipv6_specific,
993	993	};
994	994
995		-/* Initialize IPv6 support and register with inet6 stack. */
	995	+/* Initialize IPv6 support and register with socket layer. */
996	996	int sctp_v6_init(void)
997	997	{
998		- int rc = proto_register(&sctpv6_prot, 1);
	998	+ int rc;
999	999
	1000	+ /* Register the SCTP specific PF_INET6 functions. */
	1001	+ sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
	1002	+
	1003	+ /* Register the SCTP specific AF_INET6 functions. */
	1004	+ sctp_register_af(&sctp_ipv6_specific);
	1005	+
	1006	+ rc = proto_register(&sctpv6_prot, 1);
1000	1007	if (rc)
1001		- goto out;
1002		- /* Register inet6 protocol. */
1003		- rc = -EAGAIN;
1004		- if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1005		- goto out_unregister_sctp_proto;
	1008	+ return rc;
1006	1009
1007	1010	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1008	1011	inet6_register_protosw(&sctpv6_seqpacket_protosw);
1009	1012	inet6_register_protosw(&sctpv6_stream_protosw);
1010	1013
1011		- /* Register the SCTP specific PF_INET6 functions. */
1012		- sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
	1014	+ return 0;
	1015	+}
1013	1016
1014		- /* Register the SCTP specific AF_INET6 functions. */
1015		- sctp_register_af(&sctp_ipv6_specific);
1016		-
	1017	+/* Register with inet6 layer. */
	1018	+int sctp_v6_add_protocol(void)
	1019	+{
1017	1020	/* Register notifier for inet6 address additions/deletions. */
1018	1021	register_inet6addr_notifier(&sctp_inet6addr_notifier);
1019		- rc = 0;
1020		-out:
1021		- return rc;
1022		-out_unregister_sctp_proto:
1023		- proto_unregister(&sctpv6_prot);
1024		- goto out;
	1022	+
	1023	+ if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
	1024	+ return -EAGAIN;
	1025	+
	1026	+ return 0;
1025	1027	}
1026	1028
1027	1029	/* IPv6 specific exit support. */
1028	1030	void sctp_v6_exit(void)
1029	1031	{
1030		- list_del(&sctp_ipv6_specific.list);
1031		- inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1032	1032	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1033	1033	inet6_unregister_protosw(&sctpv6_stream_protosw);
1034		- unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1035	1034	proto_unregister(&sctpv6_prot);
	1035	+ list_del(&sctp_ipv6_specific.list);
	1036	+}
	1037	+
	1038	+/* Unregister with inet6 layer. */
	1039	+void sctp_v6_del_protocol(void)
	1040	+{
	1041	+ inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
	1042	+ unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1036	1043	}
...	...	@@ -975,28 +975,14 @@
975	975	if (!sctp_sanity_check())
976	976	goto out;
977	977
978		- status = proto_register(&sctp_prot, 1);
979		- if (status)
980		- goto out;
981		-
982		- /* Add SCTP to inet_protos hash table. */
983		- status = -EAGAIN;
984		- if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
985		- goto err_add_protocol;
986		-
987		- /* Add SCTP(TCP and UDP style) to inetsw linked list. */
988		- inet_register_protosw(&sctp_seqpacket_protosw);
989		- inet_register_protosw(&sctp_stream_protosw);
990		-
991		- /* Allocate a cache pools. */
	978	+ /* Allocate bind_bucket and chunk caches. */
992	979	status = -ENOBUFS;
993	980	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
994	981	sizeof(struct sctp_bind_bucket),
995	982	0, SLAB_HWCACHE_ALIGN,
996	983	NULL, NULL);
997		-
998	984	if (!sctp_bucket_cachep)
999		- goto err_bucket_cachep;
	985	+ goto out;
1000	986
1001	987	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
1002	988	sizeof(struct sctp_chunk),
...	...	@@ -1153,6 +1139,14 @@
1153	1139	INIT_LIST_HEAD(&sctp_address_families);
1154	1140	sctp_register_af(&sctp_ipv4_specific);
1155	1141
	1142	+ status = proto_register(&sctp_prot, 1);
	1143	+ if (status)
	1144	+ goto err_proto_register;
	1145	+
	1146	+ /* Register SCTP(UDP and TCP style) with socket layer. */
	1147	+ inet_register_protosw(&sctp_seqpacket_protosw);
	1148	+ inet_register_protosw(&sctp_stream_protosw);
	1149	+
1156	1150	status = sctp_v6_init();
1157	1151	if (status)
1158	1152	goto err_v6_init;
1159	1153
1160	1154
1161	1155
...	...	@@ -1166,19 +1160,39 @@
1166	1160
1167	1161	/* Initialize the local address list. */
1168	1162	INIT_LIST_HEAD(&sctp_local_addr_list);
1169		-
1170	1163	sctp_get_local_addr_list();
1171	1164
1172	1165	/* Register notifier for inet address additions/deletions. */
1173	1166	register_inetaddr_notifier(&sctp_inetaddr_notifier);
1174	1167
	1168	+ /* Register SCTP with inet layer. */
	1169	+ if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0) {
	1170	+ status = -EAGAIN;
	1171	+ goto err_add_protocol;
	1172	+ }
	1173	+
	1174	+ /* Register SCTP with inet6 layer. */
	1175	+ status = sctp_v6_add_protocol();
	1176	+ if (status)
	1177	+ goto err_v6_add_protocol;
	1178	+
1175	1179	__unsafe(THIS_MODULE);
1176	1180	status = 0;
1177	1181	out:
1178	1182	return status;
	1183	+err_v6_add_protocol:
	1184	+ inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
	1185	+ unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
	1186	+err_add_protocol:
	1187	+ sctp_free_local_addr_list();
	1188	+ sock_release(sctp_ctl_socket);
1179	1189	err_ctl_sock_init:
1180	1190	sctp_v6_exit();
1181	1191	err_v6_init:
	1192	+ inet_unregister_protosw(&sctp_stream_protosw);
	1193	+ inet_unregister_protosw(&sctp_seqpacket_protosw);
	1194	+ proto_unregister(&sctp_prot);
	1195	+err_proto_register:
1182	1196	sctp_sysctl_unregister();
1183	1197	list_del(&sctp_ipv4_specific.list);
1184	1198	free_pages((unsigned long)sctp_port_hashtable,
1185	1199
1186	1200
...	...	@@ -1192,19 +1206,13 @@
1192	1206	sizeof(struct sctp_hashbucket)));
1193	1207	err_ahash_alloc:
1194	1208	sctp_dbg_objcnt_exit();
1195		-err_init_proc:
1196	1209	sctp_proc_exit();
	1210	+err_init_proc:
1197	1211	cleanup_sctp_mibs();
1198	1212	err_init_mibs:
1199	1213	kmem_cache_destroy(sctp_chunk_cachep);
1200	1214	err_chunk_cachep:
1201	1215	kmem_cache_destroy(sctp_bucket_cachep);
1202		-err_bucket_cachep:
1203		- inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1204		- inet_unregister_protosw(&sctp_seqpacket_protosw);
1205		- inet_unregister_protosw(&sctp_stream_protosw);
1206		-err_add_protocol:
1207		- proto_unregister(&sctp_prot);
1208	1216	goto out;
1209	1217	}
1210	1218
...	...	@@ -1215,8 +1223,9 @@
1215	1223	* up all the remaining associations and all that memory.
1216	1224	*/
1217	1225
1218		- /* Unregister notifier for inet address additions/deletions. */
1219		- unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
	1226	+ /* Unregister with inet6/inet layers. */
	1227	+ sctp_v6_del_protocol();
	1228	+ inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1220	1229
1221	1230	/* Free the local address list. */
1222	1231	sctp_free_local_addr_list();
1223	1232
...	...	@@ -1224,7 +1233,16 @@
1224	1233	/* Free the control endpoint. */
1225	1234	sock_release(sctp_ctl_socket);
1226	1235
	1236	+ /* Cleanup v6 initializations. */
1227	1237	sctp_v6_exit();
	1238	+
	1239	+ /* Unregister with socket layer. */
	1240	+ inet_unregister_protosw(&sctp_stream_protosw);
	1241	+ inet_unregister_protosw(&sctp_seqpacket_protosw);
	1242	+
	1243	+ /* Unregister notifier for inet address additions/deletions. */
	1244	+ unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
	1245	+
1228	1246	sctp_sysctl_unregister();
1229	1247	list_del(&sctp_ipv4_specific.list);
1230	1248
1231	1249
...	...	@@ -1236,16 +1254,13 @@
1236	1254	get_order(sctp_port_hashsize *
1237	1255	sizeof(struct sctp_bind_hashbucket)));
1238	1256
1239		- kmem_cache_destroy(sctp_chunk_cachep);
1240		- kmem_cache_destroy(sctp_bucket_cachep);
1241		-
1242	1257	sctp_dbg_objcnt_exit();
1243	1258	sctp_proc_exit();
1244	1259	cleanup_sctp_mibs();
1245	1260
1246		- inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1247		- inet_unregister_protosw(&sctp_seqpacket_protosw);
1248		- inet_unregister_protosw(&sctp_stream_protosw);
	1261	+ kmem_cache_destroy(sctp_chunk_cachep);
	1262	+ kmem_cache_destroy(sctp_bucket_cachep);
	1263	+
1249	1264	proto_unregister(&sctp_prot);
1250	1265	}
1251	1266