From: Namjae Jeon Date: Tue, 5 Aug 2025 09:13:13 +0000 (+0900) Subject: ksmbd: limit repeated connections from clients with the same IP X-Git-Tag: v6.1.148~12 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cb092fc3a62972a4aa47c9fe356c2c6a01cd840b;p=thirdparty%2Fkernel%2Fstable.git ksmbd: limit repeated connections from clients with the same IP commit e6bb9193974059ddbb0ce7763fa3882bd60d4dc3 upstream. Repeated connections from clients with the same IP address may exhaust the max connections and prevent other normal client connections. This patch limit repeated connections from clients with the same IP. Reported-by: tianshuo han Cc: stable@vger.kernel.org Signed-off-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/smb/server/connection.h b/fs/smb/server/connection.h index 0e04cf8b1d896..0e72be594e910 100644 --- a/fs/smb/server/connection.h +++ b/fs/smb/server/connection.h @@ -45,6 +45,7 @@ struct ksmbd_conn { struct mutex srv_mutex; int status; unsigned int cli_cap; + __be32 inet_addr; char *request_buf; struct ksmbd_transport *transport; struct nls_table *local_nls; diff --git a/fs/smb/server/transport_tcp.c b/fs/smb/server/transport_tcp.c index 25f7c86ba9b98..1222cf6be5efa 100644 --- a/fs/smb/server/transport_tcp.c +++ b/fs/smb/server/transport_tcp.c @@ -87,6 +87,7 @@ static struct tcp_transport *alloc_transport(struct socket *client_sk) return NULL; } + conn->inet_addr = inet_sk(client_sk->sk)->inet_daddr; conn->transport = KSMBD_TRANS(t); KSMBD_TRANS(t)->conn = conn; KSMBD_TRANS(t)->ops = &ksmbd_tcp_transport_ops; @@ -226,6 +227,8 @@ static int ksmbd_kthread_fn(void *p) { struct socket *client_sk = NULL; struct interface *iface = (struct interface *)p; + struct inet_sock *csk_inet; + struct ksmbd_conn *conn; int ret; while (!kthread_should_stop()) { @@ -244,6 +247,20 @@ static int ksmbd_kthread_fn(void *p) continue; } + /* + * Limits repeated connections from clients with the same IP. + */ + csk_inet = inet_sk(client_sk->sk); + down_read(&conn_list_lock); + list_for_each_entry(conn, &conn_list, conns_list) + if (csk_inet->inet_daddr == conn->inet_addr) { + ret = -EAGAIN; + break; + } + up_read(&conn_list_lock); + if (ret == -EAGAIN) + continue; + if (server_conf.max_connections && atomic_inc_return(&active_num_conn) >= server_conf.max_connections) { pr_info_ratelimited("Limit the maximum number of connections(%u)\n",