1 files changed, 74 insertions, 98 deletions

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 2372538a1211..880d7cf8b730 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -72,10 +72,8 @@ static void cifs_prune_tlinks(struct work_struct *work);
  */
 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
 {
-	int rc;
-	int len;
-	char *unc;
 	struct sockaddr_storage ss;
+	int rc;
 
 	if (!server->hostname)
 		return -EINVAL;
@@ -84,32 +82,18 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
 	if (server->hostname[0] == '\0')
 		return 0;
 
-	len = strlen(server->hostname) + 3;
-
-	unc = kmalloc(len, GFP_KERNEL);
-	if (!unc) {
-		cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
-		return -ENOMEM;
-	}
-	scnprintf(unc, len, "\\\\%s", server->hostname);
-
 	spin_lock(&server->srv_lock);
 	ss = server->dstaddr;
 	spin_unlock(&server->srv_lock);
 
-	rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, NULL);
-	kfree(unc);
-
-	if (rc < 0) {
-		cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
-			 __func__, server->hostname, rc);
-	} else {
+	rc = dns_resolve_name(server->dns_dom, server->hostname,
+			      strlen(server->hostname),
+			      (struct sockaddr *)&ss);
+	if (!rc) {
 		spin_lock(&server->srv_lock);
 		memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
 		spin_unlock(&server->srv_lock);
-		rc = 0;
 	}
-
 	return rc;
 }
 
@@ -438,7 +422,8 @@ static int __cifs_reconnect(struct TCP_Server_Info *server,
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
-static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
+static int __reconnect_target_locked(struct TCP_Server_Info *server,
+				     const char *target)
 {
 	int rc;
 	char *hostname;
@@ -471,34 +456,43 @@ static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const cha
 	return rc;
 }
 
-static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
-				     struct dfs_cache_tgt_iterator **target_hint)
+static int reconnect_target_locked(struct TCP_Server_Info *server,
+				   struct dfs_cache_tgt_list *tl,
+				   struct dfs_cache_tgt_iterator **target_hint)
 {
-	int rc;
 	struct dfs_cache_tgt_iterator *tit;
+	int rc;
 
 	*target_hint = NULL;
 
 	/* If dfs target list is empty, then reconnect to last server */
 	tit = dfs_cache_get_tgt_iterator(tl);
 	if (!tit)
-		return __reconnect_target_unlocked(server, server->hostname);
+		return __reconnect_target_locked(server, server->hostname);
 
 	/* Otherwise, try every dfs target in @tl */
-	for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
-		rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
+	do {
+		const char *target = dfs_cache_get_tgt_name(tit);
+
+		spin_lock(&server->srv_lock);
+		if (server->tcpStatus != CifsNeedReconnect) {
+			spin_unlock(&server->srv_lock);
+			return -ECONNRESET;
+		}
+		spin_unlock(&server->srv_lock);
+		rc = __reconnect_target_locked(server, target);
 		if (!rc) {
 			*target_hint = tit;
 			break;
 		}
-	}
+	} while ((tit = dfs_cache_get_next_tgt(tl, tit)));
 	return rc;
 }
 
 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 {
 	struct dfs_cache_tgt_iterator *target_hint = NULL;
-
+	const char *ref_path = server->leaf_fullpath + 1;
 	DFS_CACHE_TGT_LIST(tl);
 	int num_targets = 0;
 	int rc = 0;
@@ -511,10 +505,8 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 	 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 	 * refreshing the referral, so, in this case, default it to 1.
 	 */
-	mutex_lock(&server->refpath_lock);
-	if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))
+	if (!dfs_cache_noreq_find(ref_path, NULL, &tl))
 		num_targets = dfs_cache_get_nr_tgts(&tl);
-	mutex_unlock(&server->refpath_lock);
 	if (!num_targets)
 		num_targets = 1;
 
@@ -534,7 +526,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 		try_to_freeze();
 		cifs_server_lock(server);
 
-		rc = reconnect_target_unlocked(server, &tl, &target_hint);
+		rc = reconnect_target_locked(server, &tl, &target_hint);
 		if (rc) {
 			/* Failed to reconnect socket */
 			cifs_server_unlock(server);
@@ -558,9 +550,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 	} while (server->tcpStatus == CifsNeedReconnect);
 
-	mutex_lock(&server->refpath_lock);
-	dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);
-	mutex_unlock(&server->refpath_lock);
+	dfs_cache_noreq_update_tgthint(ref_path, target_hint);
 	dfs_cache_free_tgts(&tl);
 
 	/* Need to set up echo worker again once connection has been established */
@@ -575,13 +565,8 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 
 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 {
-	mutex_lock(&server->refpath_lock);
-	if (!server->leaf_fullpath) {
-		mutex_unlock(&server->refpath_lock);
+	if (!server->leaf_fullpath)
 		return __cifs_reconnect(server, mark_smb_session);
-	}
-	mutex_unlock(&server->refpath_lock);
-
 	return reconnect_dfs_server(server);
 }
 #else
@@ -987,9 +972,13 @@ clean_demultiplex_info(struct TCP_Server_Info *server)
 	msleep(125);
 	if (cifs_rdma_enabled(server))
 		smbd_destroy(server);
+
 	if (server->ssocket) {
 		sock_release(server->ssocket);
 		server->ssocket = NULL;
+
+		/* Release netns reference for the socket. */
+		put_net(cifs_net_ns(server));
 	}
 
 	if (!list_empty(&server->pending_mid_q)) {
@@ -1037,8 +1026,10 @@ clean_demultiplex_info(struct TCP_Server_Info *server)
 		 */
 	}
 
+	/* Release netns reference for this server. */
 	put_net(cifs_net_ns(server));
 	kfree(server->leaf_fullpath);
+	kfree(server->hostname);
 	kfree(server);
 
 	length = atomic_dec_return(&tcpSesAllocCount);
@@ -1535,42 +1526,10 @@ static int match_server(struct TCP_Server_Info *server,
 	if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
 			       (struct sockaddr *)&server->srcaddr))
 		return 0;
-	/*
-	 * When matching cifs.ko superblocks (@match_super == true), we can't
-	 * really match either @server->leaf_fullpath or @server->dstaddr
-	 * directly since this @server might belong to a completely different
-	 * server -- in case of domain-based DFS referrals or DFS links -- as
-	 * provided earlier by mount(2) through 'source' and 'ip' options.
-	 *
-	 * Otherwise, match the DFS referral in @server->leaf_fullpath or the
-	 * destination address in @server->dstaddr.
-	 *
-	 * When using 'nodfs' mount option, we avoid sharing it with DFS
-	 * connections as they might failover.
-	 */
-	if (!match_super) {
-		if (!ctx->nodfs) {
-			if (server->leaf_fullpath) {
-				if (!ctx->leaf_fullpath ||
-				    strcasecmp(server->leaf_fullpath,
-					       ctx->leaf_fullpath))
-					return 0;
-			} else if (ctx->leaf_fullpath) {
-				return 0;
-			}
-		} else if (server->leaf_fullpath) {
-			return 0;
-		}
-	}
 
-	/*
-	 * Match for a regular connection (address/hostname/port) which has no
-	 * DFS referrals set.
-	 */
-	if (!server->leaf_fullpath &&
-	    (strcasecmp(server->hostname, ctx->server_hostname) ||
-	     !match_server_address(server, addr) ||
-	     !match_port(server, addr)))
+	if (strcasecmp(server->hostname, ctx->server_hostname) ||
+	    !match_server_address(server, addr) ||
+	    !match_port(server, addr))
 		return 0;
 
 	if (!match_security(server, ctx))
@@ -1665,8 +1624,6 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
 	kfree_sensitive(server->session_key.response);
 	server->session_key.response = NULL;
 	server->session_key.len = 0;
-	kfree(server->hostname);
-	server->hostname = NULL;
 
 	task = xchg(&server->tsk, NULL);
 	if (task)
@@ -1706,6 +1663,8 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 			goto out_err;
 		}
 	}
+	if (ctx->dns_dom)
+		strscpy(tcp_ses->dns_dom, ctx->dns_dom);
 
 	if (ctx->nosharesock)
 		tcp_ses->nosharesock = true;
@@ -1713,6 +1672,8 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 
 	tcp_ses->ops = ctx->ops;
 	tcp_ses->vals = ctx->vals;
+
+	/* Grab netns reference for this server. */
 	cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
 
 	tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
@@ -1752,9 +1713,6 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 	INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
 	INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
 	mutex_init(&tcp_ses->reconnect_mutex);
-#ifdef CONFIG_CIFS_DFS_UPCALL
-	mutex_init(&tcp_ses->refpath_lock);
-#endif
 	memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
 	       sizeof(tcp_ses->srcaddr));
 	memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
@@ -1844,6 +1802,7 @@ smbd_connected:
 out_err_crypto_release:
 	cifs_crypto_secmech_release(tcp_ses);
 
+	/* Release netns reference for this server. */
 	put_net(cifs_net_ns(tcp_ses));
 
 out_err:
@@ -1852,8 +1811,10 @@ out_err:
 			cifs_put_tcp_session(tcp_ses->primary_server, false);
 		kfree(tcp_ses->hostname);
 		kfree(tcp_ses->leaf_fullpath);
-		if (tcp_ses->ssocket)
+		if (tcp_ses->ssocket) {
 			sock_release(tcp_ses->ssocket);
+			put_net(cifs_net_ns(tcp_ses));
+		}
 		kfree(tcp_ses);
 	}
 	return ERR_PTR(rc);
@@ -2267,12 +2228,13 @@ cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
 struct cifs_ses *
 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 {
-	int rc = 0;
-	int retries = 0;
-	unsigned int xid;
-	struct cifs_ses *ses;
-	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
+	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
+	struct cifs_ses *ses;
+	unsigned int xid;
+	int retries = 0;
+	size_t len;
+	int rc = 0;
 
 	xid = get_xid();
 
@@ -2362,6 +2324,14 @@ retry_old_session:
 		ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
 		if (!ses->domainName)
 			goto get_ses_fail;
+
+		len = strnlen(ctx->domainname, CIFS_MAX_DOMAINNAME_LEN);
+		if (!cifs_netbios_name(ctx->domainname, len)) {
+			ses->dns_dom = kstrndup(ctx->domainname,
+						len, GFP_KERNEL);
+			if (!ses->dns_dom)
+				goto get_ses_fail;
+		}
 	}
 
 	strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
@@ -3131,20 +3101,20 @@ generic_ip_connect(struct TCP_Server_Info *server)
 		socket = server->ssocket;
 	} else {
 		struct net *net = cifs_net_ns(server);
-		struct sock *sk;
 
-		rc = __sock_create(net, sfamily, SOCK_STREAM,
-				   IPPROTO_TCP, &server->ssocket, 1);
+		rc = sock_create_kern(net, sfamily, SOCK_STREAM, IPPROTO_TCP, &server->ssocket);
 		if (rc < 0) {
 			cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
 			return rc;
 		}
 
-		sk = server->ssocket->sk;
-		__netns_tracker_free(net, &sk->ns_tracker, false);
-		sk->sk_net_refcnt = 1;
-		get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
-		sock_inuse_add(net, 1);
+		/*
+		 * Grab netns reference for the socket.
+		 *
+		 * It'll be released here, on error, or in clean_demultiplex_info() upon server
+		 * teardown.
+		 */
+		get_net(net);
 
 		/* BB other socket options to set KEEPALIVE, NODELAY? */
 		cifs_dbg(FYI, "Socket created\n");
@@ -3158,8 +3128,10 @@ generic_ip_connect(struct TCP_Server_Info *server)
 	}
 
 	rc = bind_socket(server);
-	if (rc < 0)
+	if (rc < 0) {
+		put_net(cifs_net_ns(server));
 		return rc;
+	}
 
 	/*
 	 * Eventually check for other socket options to change from
@@ -3196,6 +3168,7 @@ generic_ip_connect(struct TCP_Server_Info *server)
 	if (rc < 0) {
 		cifs_dbg(FYI, "Error %d connecting to server\n", rc);
 		trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
+		put_net(cifs_net_ns(server));
 		sock_release(socket);
 		server->ssocket = NULL;
 		return rc;
@@ -3204,6 +3177,9 @@ generic_ip_connect(struct TCP_Server_Info *server)
 	if (sport == htons(RFC1001_PORT))
 		rc = ip_rfc1001_connect(server);
 
+	if (rc < 0)
+		put_net(cifs_net_ns(server));
+
 	return rc;
 }