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authorVlad Yasevich <vladislav.yasevich@hp.com>2008-03-20 18:17:14 -0400
committerDavid S. Miller <davem@davemloft.net>2008-03-20 18:17:14 -0400
commit270637abff0cdf848b910b9f96ad342e1da61c66 (patch)
treec5335ff19071e083588240da49b2aac27a402d8b /net
parentd0ebf133590abdc035af6e19a6568667af0ab3b0 (diff)
[SCTP]: Fix a race between module load and protosw access
There is a race is SCTP between the loading of the module and the access by the socket layer to the protocol functions. In particular, a list of addresss that SCTP maintains is not initialized prior to the registration with the protosw. Thus it is possible for a user application to gain access to SCTP functions before everything has been initialized. The problem shows up as odd crashes during connection initializtion when we try to access the SCTP address list. The solution is to refactor how we do registration and initialize the lists prior to registering with the protosw. Care must be taken since the address list initialization depends on some other pieces of SCTP initialization. Also the clean-up in case of failure now also needs to be refactored. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Acked-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/sctp/ipv6.c32
-rw-r--r--net/sctp/protocol.c129
2 files changed, 104 insertions, 57 deletions
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 9aa0733aee87..b1e05d719f9b 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -1014,15 +1014,24 @@ static struct sctp_pf sctp_pf_inet6 = {
1014}; 1014};
1015 1015
1016/* Initialize IPv6 support and register with socket layer. */ 1016/* Initialize IPv6 support and register with socket layer. */
1017int sctp_v6_init(void) 1017void sctp_v6_pf_init(void)
1018{ 1018{
1019 int rc;
1020
1021 /* Register the SCTP specific PF_INET6 functions. */ 1019 /* Register the SCTP specific PF_INET6 functions. */
1022 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1020 sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1023 1021
1024 /* Register the SCTP specific AF_INET6 functions. */ 1022 /* Register the SCTP specific AF_INET6 functions. */
1025 sctp_register_af(&sctp_af_inet6); 1023 sctp_register_af(&sctp_af_inet6);
1024}
1025
1026void sctp_v6_pf_exit(void)
1027{
1028 list_del(&sctp_af_inet6.list);
1029}
1030
1031/* Initialize IPv6 support and register with socket layer. */
1032int sctp_v6_protosw_init(void)
1033{
1034 int rc;
1026 1035
1027 rc = proto_register(&sctpv6_prot, 1); 1036 rc = proto_register(&sctpv6_prot, 1);
1028 if (rc) 1037 if (rc)
@@ -1035,6 +1044,14 @@ int sctp_v6_init(void)
1035 return 0; 1044 return 0;
1036} 1045}
1037 1046
1047void sctp_v6_protosw_exit(void)
1048{
1049 inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1050 inet6_unregister_protosw(&sctpv6_stream_protosw);
1051 proto_unregister(&sctpv6_prot);
1052}
1053
1054
1038/* Register with inet6 layer. */ 1055/* Register with inet6 layer. */
1039int sctp_v6_add_protocol(void) 1056int sctp_v6_add_protocol(void)
1040{ 1057{
@@ -1047,15 +1064,6 @@ int sctp_v6_add_protocol(void)
1047 return 0; 1064 return 0;
1048} 1065}
1049 1066
1050/* IPv6 specific exit support. */
1051void sctp_v6_exit(void)
1052{
1053 inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1054 inet6_unregister_protosw(&sctpv6_stream_protosw);
1055 proto_unregister(&sctpv6_prot);
1056 list_del(&sctp_af_inet6.list);
1057}
1058
1059/* Unregister with inet6 layer. */ 1067/* Unregister with inet6 layer. */
1060void sctp_v6_del_protocol(void) 1068void sctp_v6_del_protocol(void)
1061{ 1069{
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 7a7646a9565c..f90091a1b9ce 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -992,6 +992,58 @@ static void cleanup_sctp_mibs(void)
992 free_percpu(sctp_statistics[1]); 992 free_percpu(sctp_statistics[1]);
993} 993}
994 994
995static void sctp_v4_pf_init(void)
996{
997 /* Initialize the SCTP specific PF functions. */
998 sctp_register_pf(&sctp_pf_inet, PF_INET);
999 sctp_register_af(&sctp_af_inet);
1000}
1001
1002static void sctp_v4_pf_exit(void)
1003{
1004 list_del(&sctp_af_inet.list);
1005}
1006
1007static int sctp_v4_protosw_init(void)
1008{
1009 int rc;
1010
1011 rc = proto_register(&sctp_prot, 1);
1012 if (rc)
1013 return rc;
1014
1015 /* Register SCTP(UDP and TCP style) with socket layer. */
1016 inet_register_protosw(&sctp_seqpacket_protosw);
1017 inet_register_protosw(&sctp_stream_protosw);
1018
1019 return 0;
1020}
1021
1022static void sctp_v4_protosw_exit(void)
1023{
1024 inet_unregister_protosw(&sctp_stream_protosw);
1025 inet_unregister_protosw(&sctp_seqpacket_protosw);
1026 proto_unregister(&sctp_prot);
1027}
1028
1029static int sctp_v4_add_protocol(void)
1030{
1031 /* Register notifier for inet address additions/deletions. */
1032 register_inetaddr_notifier(&sctp_inetaddr_notifier);
1033
1034 /* Register SCTP with inet layer. */
1035 if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1036 return -EAGAIN;
1037
1038 return 0;
1039}
1040
1041static void sctp_v4_del_protocol(void)
1042{
1043 inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1044 unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1045}
1046
995/* Initialize the universe into something sensible. */ 1047/* Initialize the universe into something sensible. */
996SCTP_STATIC __init int sctp_init(void) 1048SCTP_STATIC __init int sctp_init(void)
997{ 1049{
@@ -1035,8 +1087,6 @@ SCTP_STATIC __init int sctp_init(void)
1035 /* Initialize object count debugging. */ 1087 /* Initialize object count debugging. */
1036 sctp_dbg_objcnt_init(); 1088 sctp_dbg_objcnt_init();
1037 1089
1038 /* Initialize the SCTP specific PF functions. */
1039 sctp_register_pf(&sctp_pf_inet, PF_INET);
1040 /* 1090 /*
1041 * 14. Suggested SCTP Protocol Parameter Values 1091 * 14. Suggested SCTP Protocol Parameter Values
1042 */ 1092 */
@@ -1194,19 +1244,22 @@ SCTP_STATIC __init int sctp_init(void)
1194 sctp_sysctl_register(); 1244 sctp_sysctl_register();
1195 1245
1196 INIT_LIST_HEAD(&sctp_address_families); 1246 INIT_LIST_HEAD(&sctp_address_families);
1197 sctp_register_af(&sctp_af_inet); 1247 sctp_v4_pf_init();
1248 sctp_v6_pf_init();
1198 1249
1199 status = proto_register(&sctp_prot, 1); 1250 /* Initialize the local address list. */
1200 if (status) 1251 INIT_LIST_HEAD(&sctp_local_addr_list);
1201 goto err_proto_register; 1252 spin_lock_init(&sctp_local_addr_lock);
1253 sctp_get_local_addr_list();
1202 1254
1203 /* Register SCTP(UDP and TCP style) with socket layer. */ 1255 status = sctp_v4_protosw_init();
1204 inet_register_protosw(&sctp_seqpacket_protosw);
1205 inet_register_protosw(&sctp_stream_protosw);
1206 1256
1207 status = sctp_v6_init();
1208 if (status) 1257 if (status)
1209 goto err_v6_init; 1258 goto err_protosw_init;
1259
1260 status = sctp_v6_protosw_init();
1261 if (status)
1262 goto err_v6_protosw_init;
1210 1263
1211 /* Initialize the control inode/socket for handling OOTB packets. */ 1264 /* Initialize the control inode/socket for handling OOTB packets. */
1212 if ((status = sctp_ctl_sock_init())) { 1265 if ((status = sctp_ctl_sock_init())) {
@@ -1215,19 +1268,9 @@ SCTP_STATIC __init int sctp_init(void)
1215 goto err_ctl_sock_init; 1268 goto err_ctl_sock_init;
1216 } 1269 }
1217 1270
1218 /* Initialize the local address list. */ 1271 status = sctp_v4_add_protocol();
1219 INIT_LIST_HEAD(&sctp_local_addr_list); 1272 if (status)
1220 spin_lock_init(&sctp_local_addr_lock);
1221 sctp_get_local_addr_list();
1222
1223 /* Register notifier for inet address additions/deletions. */
1224 register_inetaddr_notifier(&sctp_inetaddr_notifier);
1225
1226 /* Register SCTP with inet layer. */
1227 if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0) {
1228 status = -EAGAIN;
1229 goto err_add_protocol; 1273 goto err_add_protocol;
1230 }
1231 1274
1232 /* Register SCTP with inet6 layer. */ 1275 /* Register SCTP with inet6 layer. */
1233 status = sctp_v6_add_protocol(); 1276 status = sctp_v6_add_protocol();
@@ -1238,18 +1281,18 @@ SCTP_STATIC __init int sctp_init(void)
1238out: 1281out:
1239 return status; 1282 return status;
1240err_v6_add_protocol: 1283err_v6_add_protocol:
1241 inet_del_protocol(&sctp_protocol, IPPROTO_SCTP); 1284 sctp_v6_del_protocol();
1242 unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1243err_add_protocol: 1285err_add_protocol:
1244 sctp_free_local_addr_list(); 1286 sctp_v4_del_protocol();
1245 sock_release(sctp_ctl_socket); 1287 sock_release(sctp_ctl_socket);
1246err_ctl_sock_init: 1288err_ctl_sock_init:
1247 sctp_v6_exit(); 1289 sctp_v6_protosw_exit();
1248err_v6_init: 1290err_v6_protosw_init:
1249 inet_unregister_protosw(&sctp_stream_protosw); 1291 sctp_v4_protosw_exit();
1250 inet_unregister_protosw(&sctp_seqpacket_protosw); 1292err_protosw_init:
1251 proto_unregister(&sctp_prot); 1293 sctp_free_local_addr_list();
1252err_proto_register: 1294 sctp_v4_pf_exit();
1295 sctp_v6_pf_exit();
1253 sctp_sysctl_unregister(); 1296 sctp_sysctl_unregister();
1254 list_del(&sctp_af_inet.list); 1297 list_del(&sctp_af_inet.list);
1255 free_pages((unsigned long)sctp_port_hashtable, 1298 free_pages((unsigned long)sctp_port_hashtable,
@@ -1282,23 +1325,21 @@ SCTP_STATIC __exit void sctp_exit(void)
1282 1325
1283 /* Unregister with inet6/inet layers. */ 1326 /* Unregister with inet6/inet layers. */
1284 sctp_v6_del_protocol(); 1327 sctp_v6_del_protocol();
1285 inet_del_protocol(&sctp_protocol, IPPROTO_SCTP); 1328 sctp_v4_del_protocol();
1286
1287 /* Unregister notifier for inet address additions/deletions. */
1288 unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1289
1290 /* Free the local address list. */
1291 sctp_free_local_addr_list();
1292 1329
1293 /* Free the control endpoint. */ 1330 /* Free the control endpoint. */
1294 sock_release(sctp_ctl_socket); 1331 sock_release(sctp_ctl_socket);
1295 1332
1296 /* Cleanup v6 initializations. */ 1333 /* Free protosw registrations */
1297 sctp_v6_exit(); 1334 sctp_v6_protosw_exit();
1335 sctp_v4_protosw_exit();
1336
1337 /* Free the local address list. */
1338 sctp_free_local_addr_list();
1298 1339
1299 /* Unregister with socket layer. */ 1340 /* Unregister with socket layer. */
1300 inet_unregister_protosw(&sctp_stream_protosw); 1341 sctp_v6_pf_exit();
1301 inet_unregister_protosw(&sctp_seqpacket_protosw); 1342 sctp_v4_pf_exit();
1302 1343
1303 sctp_sysctl_unregister(); 1344 sctp_sysctl_unregister();
1304 list_del(&sctp_af_inet.list); 1345 list_del(&sctp_af_inet.list);
@@ -1317,8 +1358,6 @@ SCTP_STATIC __exit void sctp_exit(void)
1317 1358
1318 kmem_cache_destroy(sctp_chunk_cachep); 1359 kmem_cache_destroy(sctp_chunk_cachep);
1319 kmem_cache_destroy(sctp_bucket_cachep); 1360 kmem_cache_destroy(sctp_bucket_cachep);
1320
1321 proto_unregister(&sctp_prot);
1322} 1361}
1323 1362
1324module_init(sctp_init); 1363module_init(sctp_init);