6.1-stable review patch. If anyone has any objections, please let me know.
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From: Namjae Jeon linkinjeon@kernel.org
[ Upstream commit d8b6dc9256762293048bf122fc11c4e612d0ef5d ]
This parameter set the maximum number of connections per ip address. The default is 8.
Cc: stable@vger.kernel.org Fixes: c0d41112f1a5 ("ksmbd: extend the connection limiting mechanism to support IPv6") Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com [ adjust reserved room ] Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/server/ksmbd_netlink.h | 5 +++-- fs/smb/server/server.h | 1 + fs/smb/server/transport_ipc.c | 3 +++ fs/smb/server/transport_tcp.c | 27 ++++++++++++++++----------- 4 files changed, 23 insertions(+), 13 deletions(-)
--- a/fs/smb/server/ksmbd_netlink.h +++ b/fs/smb/server/ksmbd_netlink.h @@ -107,10 +107,11 @@ struct ksmbd_startup_request { __u32 smb2_max_credits; /* MAX credits */ __u32 smbd_max_io_size; /* smbd read write size */ __u32 max_connections; /* Number of maximum simultaneous connections */ - __u32 reserved[126]; /* Reserved room */ + __u32 max_ip_connections; /* Number of maximum connection per ip address */ + __u32 reserved[125]; /* Reserved room */ __u32 ifc_list_sz; /* interfaces list size */ __s8 ____payload[]; -}; +} __packed;
#define KSMBD_STARTUP_CONFIG_INTERFACES(s) ((s)->____payload)
--- a/fs/smb/server/server.h +++ b/fs/smb/server/server.h @@ -42,6 +42,7 @@ struct ksmbd_server_config { struct smb_sid domain_sid; unsigned int auth_mechs; unsigned int max_connections; + unsigned int max_ip_connections;
char *conf[SERVER_CONF_WORK_GROUP + 1]; }; --- a/fs/smb/server/transport_ipc.c +++ b/fs/smb/server/transport_ipc.c @@ -318,6 +318,9 @@ static int ipc_server_config_on_startup( if (req->max_connections) server_conf.max_connections = req->max_connections;
+ if (req->max_ip_connections) + server_conf.max_ip_connections = req->max_ip_connections; + ret = ksmbd_set_netbios_name(req->netbios_name); ret |= ksmbd_set_server_string(req->server_string); ret |= ksmbd_set_work_group(req->work_group); --- a/fs/smb/server/transport_tcp.c +++ b/fs/smb/server/transport_tcp.c @@ -236,6 +236,7 @@ static int ksmbd_kthread_fn(void *p) struct interface *iface = (struct interface *)p; struct ksmbd_conn *conn; int ret; + unsigned int max_ip_conns;
while (!kthread_should_stop()) { mutex_lock(&iface->sock_release_lock); @@ -253,34 +254,38 @@ static int ksmbd_kthread_fn(void *p) continue; }
+ if (!server_conf.max_ip_connections) + goto skip_max_ip_conns_limit; + /* * Limits repeated connections from clients with the same IP. */ + max_ip_conns = 0; down_read(&conn_list_lock); - list_for_each_entry(conn, &conn_list, conns_list) + list_for_each_entry(conn, &conn_list, conns_list) { #if IS_ENABLED(CONFIG_IPV6) if (client_sk->sk->sk_family == AF_INET6) { if (memcmp(&client_sk->sk->sk_v6_daddr, - &conn->inet6_addr, 16) == 0) { - ret = -EAGAIN; - break; - } + &conn->inet6_addr, 16) == 0) + max_ip_conns++; } else if (inet_sk(client_sk->sk)->inet_daddr == - conn->inet_addr) { - ret = -EAGAIN; - break; - } + conn->inet_addr) + max_ip_conns++; #else if (inet_sk(client_sk->sk)->inet_daddr == - conn->inet_addr) { + conn->inet_addr) + max_ip_conns++; +#endif + if (server_conf.max_ip_connections <= max_ip_conns) { ret = -EAGAIN; break; } -#endif + } up_read(&conn_list_lock); if (ret == -EAGAIN) continue;
+skip_max_ip_conns_limit: 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",