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 c1883049aa9b2b7dffd3a68c5fc67fa92c174bd9 ]
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 seanheelan@gmail.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b1c2219ec0b42..3bcfe739ba136 100644 --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -255,6 +255,22 @@ 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 ce91b1d698e71..f4da293c4dbb2 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 646c4047d3b94..12bf3712ba2d3 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1723,44 +1723,38 @@ 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; } @@ -1926,6 +1920,8 @@ 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);