From: Namjae Jeon <linkinjeon@kernel.org> mainline inclusion from mainline-v6.17-rc1 commit e6bb9193974059ddbb0ce7763fa3882bd60d4dc3 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICT9UF CVE: CVE-2025-38501 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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: Yongjian Sun <sunyongjian1@huawei.com> --- fs/smb/server/connection.h | 1 + fs/smb/server/transport_tcp.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/fs/smb/server/connection.h b/fs/smb/server/connection.h index 4fdd76ce53b9..70edeff46165 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 2ce7f75059cb..84bc283e5689 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", -- 2.39.2