diff options
author | Namjae Jeon | 2021-10-13 17:28:31 +0900 |
---|---|---|
committer | Steve French | 2021-10-20 00:07:10 -0500 |
commit | 621be84a9d1fbf0097fd058e249ec5cc4f35f3c5 (patch) | |
tree | e6d922ce3d5262c34c781768ee51588ce4c80e2e | |
parent | 34061d6b76a41b1e43c19e1e50d98e5d77f77d4e (diff) |
ksmbd: throttle session setup failures to avoid dictionary attacks
To avoid dictionary attacks (repeated session setups rapidly sent) to
connect to server, ksmbd make a delay of a 5 seconds on session setup
failure to make it harder to send enough random connection requests
to break into a server if a user insert the wrong password 10 times
in a row.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
-rw-r--r-- | fs/ksmbd/ksmbd_netlink.h | 2 | ||||
-rw-r--r-- | fs/ksmbd/mgmt/user_config.c | 2 | ||||
-rw-r--r-- | fs/ksmbd/mgmt/user_config.h | 1 | ||||
-rw-r--r-- | fs/ksmbd/smb2pdu.c | 27 | ||||
-rw-r--r-- | fs/ksmbd/transport_ipc.c | 3 | ||||
-rw-r--r-- | fs/ksmbd/transport_ipc.h | 2 |
6 files changed, 31 insertions, 6 deletions
diff --git a/fs/ksmbd/ksmbd_netlink.h b/fs/ksmbd/ksmbd_netlink.h index 2fbe2bc1e093..c6718a05d347 100644 --- a/fs/ksmbd/ksmbd_netlink.h +++ b/fs/ksmbd/ksmbd_netlink.h @@ -211,6 +211,7 @@ struct ksmbd_tree_disconnect_request { */ struct ksmbd_logout_request { __s8 account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ]; /* user account name */ + __u32 account_flags; }; /* @@ -317,6 +318,7 @@ enum KSMBD_TREE_CONN_STATUS { #define KSMBD_USER_FLAG_BAD_UID BIT(2) #define KSMBD_USER_FLAG_BAD_USER BIT(3) #define KSMBD_USER_FLAG_GUEST_ACCOUNT BIT(4) +#define KSMBD_USER_FLAG_DELAY_SESSION BIT(5) /* * Share config flags. diff --git a/fs/ksmbd/mgmt/user_config.c b/fs/ksmbd/mgmt/user_config.c index d21629ae5c89..1019d3677d55 100644 --- a/fs/ksmbd/mgmt/user_config.c +++ b/fs/ksmbd/mgmt/user_config.c @@ -55,7 +55,7 @@ struct ksmbd_user *ksmbd_alloc_user(struct ksmbd_login_response *resp) void ksmbd_free_user(struct ksmbd_user *user) { - ksmbd_ipc_logout_request(user->name); + ksmbd_ipc_logout_request(user->name, user->flags); kfree(user->name); kfree(user->passkey); kfree(user); diff --git a/fs/ksmbd/mgmt/user_config.h b/fs/ksmbd/mgmt/user_config.h index b2bb074a0150..aff80b029579 100644 --- a/fs/ksmbd/mgmt/user_config.h +++ b/fs/ksmbd/mgmt/user_config.h @@ -18,6 +18,7 @@ struct ksmbd_user { size_t passkey_sz; char *passkey; + unsigned int failed_login_count; }; static inline bool user_guest(struct ksmbd_user *user) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index e0f3a44e1599..cf7db5f71f9b 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1779,9 +1779,30 @@ out_err: conn->mechToken = NULL; } - if (rc < 0 && sess) { - ksmbd_session_destroy(sess); - work->sess = NULL; + if (rc < 0) { + /* + * SecurityBufferOffset should be set to zero + * in session setup error response. + */ + rsp->SecurityBufferOffset = 0; + + if (sess) { + bool try_delay = false; + + /* + * To avoid dictionary attacks (repeated session setups rapidly sent) to + * connect to server, ksmbd make a delay of a 5 seconds on session setup + * failure to make it harder to send enough random connection requests + * to break into a server. + */ + if (sess->user && sess->user->flags & KSMBD_USER_FLAG_DELAY_SESSION) + try_delay = true; + + ksmbd_session_destroy(sess); + work->sess = NULL; + if (try_delay) + ssleep(5); + } } return rc; diff --git a/fs/ksmbd/transport_ipc.c b/fs/ksmbd/transport_ipc.c index 44aea33a67fa..1acf1892a466 100644 --- a/fs/ksmbd/transport_ipc.c +++ b/fs/ksmbd/transport_ipc.c @@ -601,7 +601,7 @@ int ksmbd_ipc_tree_disconnect_request(unsigned long long session_id, return ret; } -int ksmbd_ipc_logout_request(const char *account) +int ksmbd_ipc_logout_request(const char *account, int flags) { struct ksmbd_ipc_msg *msg; struct ksmbd_logout_request *req; @@ -616,6 +616,7 @@ int ksmbd_ipc_logout_request(const char *account) msg->type = KSMBD_EVENT_LOGOUT_REQUEST; req = (struct ksmbd_logout_request *)msg->payload; + req->account_flags = flags; strscpy(req->account, account, KSMBD_REQ_MAX_ACCOUNT_NAME_SZ); ret = ipc_msg_send(msg); diff --git a/fs/ksmbd/transport_ipc.h b/fs/ksmbd/transport_ipc.h index 9eacc895ffdb..5e5b90a0c187 100644 --- a/fs/ksmbd/transport_ipc.h +++ b/fs/ksmbd/transport_ipc.h @@ -25,7 +25,7 @@ ksmbd_ipc_tree_connect_request(struct ksmbd_session *sess, struct sockaddr *peer_addr); int ksmbd_ipc_tree_disconnect_request(unsigned long long session_id, unsigned long long connect_id); -int ksmbd_ipc_logout_request(const char *account); +int ksmbd_ipc_logout_request(const char *account, int flags); struct ksmbd_share_config_response * ksmbd_ipc_share_config_request(const char *name); struct ksmbd_spnego_authen_response * |