From c1883049aa9b2b7dffd3a68c5fc67fa92c174bd9 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Mon, 24 Mar 2025 20:19:20 +0900 Subject: [PATCH] ksmbd: fix multichannel connection failure ksmbd check that the session of second channel is in the session list of first connection. If it is in session list, multichannel connection should not be allowed. Fixes: b95629435b84 ("ksmbd: fix racy issue from session lookup and expire") Reported-by: Sean Heelan Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/mgmt/user_session.c | 16 ++++++++++++++++ fs/smb/server/mgmt/user_session.h | 2 ++ fs/smb/server/smb2pdu.c | 12 ++++-------- 3 files changed, 22 insertions(+), 8 deletions(-) diff --git a/fs/smb/server/mgmt/user_session.c b/fs/smb/server/mgmt/user_session.c index 1ecca6785ed0c..53d308f331af8 100644 --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -259,6 +259,22 @@ void ksmbd_sessions_deregister(struct ksmbd_conn *conn) up_write(&sessions_table_lock); } +bool is_ksmbd_session_in_connection(struct ksmbd_conn *conn, + unsigned long long id) +{ + struct ksmbd_session *sess; + + down_read(&conn->session_lock); + sess = xa_load(&conn->sessions, id); + if (sess) { + up_read(&conn->session_lock); + return true; + } + up_read(&conn->session_lock); + + return false; +} + struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn, unsigned long long id) { diff --git a/fs/smb/server/mgmt/user_session.h b/fs/smb/server/mgmt/user_session.h index c1c4b20bd5c6c..f21348381d598 100644 --- a/fs/smb/server/mgmt/user_session.h +++ b/fs/smb/server/mgmt/user_session.h @@ -87,6 +87,8 @@ void ksmbd_session_destroy(struct ksmbd_session *sess); struct ksmbd_session *ksmbd_session_lookup_slowpath(unsigned long long id); struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn, unsigned long long id); +bool is_ksmbd_session_in_connection(struct ksmbd_conn *conn, + unsigned long long id); int ksmbd_session_register(struct ksmbd_conn *conn, struct ksmbd_session *sess); void ksmbd_sessions_deregister(struct ksmbd_conn *conn); diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 7717d81d3f9be..4ddf4300371b8 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1707,44 +1707,38 @@ int smb2_sess_setup(struct ksmbd_work *work) if (conn->dialect != sess->dialect) { rc = -EINVAL; - ksmbd_user_session_put(sess); goto out_err; } if (!(req->hdr.Flags & SMB2_FLAGS_SIGNED)) { rc = -EINVAL; - ksmbd_user_session_put(sess); goto out_err; } if (strncmp(conn->ClientGUID, sess->ClientGUID, SMB2_CLIENT_GUID_SIZE)) { rc = -ENOENT; - ksmbd_user_session_put(sess); goto out_err; } if (sess->state == SMB2_SESSION_IN_PROGRESS) { rc = -EACCES; - ksmbd_user_session_put(sess); goto out_err; } if (sess->state == SMB2_SESSION_EXPIRED) { rc = -EFAULT; - ksmbd_user_session_put(sess); goto out_err; } - ksmbd_user_session_put(sess); if (ksmbd_conn_need_reconnect(conn)) { rc = -EFAULT; + ksmbd_user_session_put(sess); sess = NULL; goto out_err; } - sess = ksmbd_session_lookup(conn, sess_id); - if (!sess) { + if (is_ksmbd_session_in_connection(conn, sess_id)) { rc = -EACCES; goto out_err; } @@ -1910,6 +1904,8 @@ int smb2_sess_setup(struct ksmbd_work *work) sess->last_active = jiffies; sess->state = SMB2_SESSION_EXPIRED; + ksmbd_user_session_put(sess); + work->sess = NULL; if (try_delay) { ksmbd_conn_set_need_reconnect(conn); ssleep(5);