summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorNamjae Jeon <linkinjeon@kernel.org>2025-08-05 18:13:13 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-08-15 16:39:32 +0200
commit6073afe64510c302b7a0683a01e32c012eff715d (patch)
tree533fbf190ac8eca2f18bf85602be99834551f0de
parentf8517f20dcd6f5207b1fc523d08b3724a17c7e7d (diff)
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 <hantianshuo233@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/smb/server/connection.h1
-rw-r--r--fs/smb/server/transport_tcp.c17
2 files changed, 18 insertions, 0 deletions
diff --git a/fs/smb/server/connection.h b/fs/smb/server/connection.h
index dd3e0e3f7bf0..31dd1caac1e8 100644
--- a/fs/smb/server/connection.h
+++ b/fs/smb/server/connection.h
@@ -46,6 +46,7 @@ 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 4e9f98db9ff4..d72588f33b9c 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;
@@ -230,6 +231,8 @@ 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()) {
@@ -248,6 +251,20 @@ 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",