6.10-stable review patch. If anyone has any objections, please let me know.
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From: Namjae Jeon linkinjeon@kernel.org
[ Upstream commit 76e98a158b207771a6c9a0de0a60522a446a3447 ]
If there is ->PreviousSessionId field in the session setup request, The session of the previous connection should be destroyed. During this, if the smb2 operation requests in the previous session are being processed, a racy issue could happen with ksmbd_destroy_file_table(). This patch sets conn->status to KSMBD_SESS_NEED_RECONNECT to block incoming operations and waits until on-going operations are complete (i.e. idle) before desctorying the previous session.
Fixes: c8efcc786146 ("ksmbd: add support for durable handles v1/v2") Cc: stable@vger.kernel.org # v6.6+ Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25040 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 --- fs/smb/server/connection.c | 34 +++++++++++++++++++++++++++++++++- fs/smb/server/connection.h | 3 ++- fs/smb/server/mgmt/user_session.c | 8 ++++++++ fs/smb/server/smb2pdu.c | 2 +- 4 files changed, 44 insertions(+), 3 deletions(-)
--- a/fs/smb/server/connection.c +++ b/fs/smb/server/connection.c @@ -165,11 +165,43 @@ void ksmbd_all_conn_set_status(u64 sess_ up_read(&conn_list_lock); }
-void ksmbd_conn_wait_idle(struct ksmbd_conn *conn, u64 sess_id) +void ksmbd_conn_wait_idle(struct ksmbd_conn *conn) { wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2); }
+int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id) +{ + struct ksmbd_conn *conn; + int rc, retry_count = 0, max_timeout = 120; + int rcount = 1; + +retry_idle: + if (retry_count >= max_timeout) + return -EIO; + + down_read(&conn_list_lock); + list_for_each_entry(conn, &conn_list, conns_list) { + if (conn->binding || xa_load(&conn->sessions, sess_id)) { + if (conn == curr_conn) + rcount = 2; + if (atomic_read(&conn->req_running) >= rcount) { + rc = wait_event_timeout(conn->req_running_q, + atomic_read(&conn->req_running) < rcount, + HZ); + if (!rc) { + up_read(&conn_list_lock); + retry_count++; + goto retry_idle; + } + } + } + } + up_read(&conn_list_lock); + + return 0; +} + int ksmbd_conn_write(struct ksmbd_work *work) { struct ksmbd_conn *conn = work->conn; --- a/fs/smb/server/connection.h +++ b/fs/smb/server/connection.h @@ -145,7 +145,8 @@ extern struct list_head conn_list; extern struct rw_semaphore conn_list_lock;
bool ksmbd_conn_alive(struct ksmbd_conn *conn); -void ksmbd_conn_wait_idle(struct ksmbd_conn *conn, u64 sess_id); +void ksmbd_conn_wait_idle(struct ksmbd_conn *conn); +int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id); struct ksmbd_conn *ksmbd_conn_alloc(void); void ksmbd_conn_free(struct ksmbd_conn *conn); bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c); --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -310,6 +310,7 @@ void destroy_previous_session(struct ksm { struct ksmbd_session *prev_sess; struct ksmbd_user *prev_user; + int err;
down_write(&sessions_table_lock); down_write(&conn->session_lock); @@ -324,8 +325,15 @@ void destroy_previous_session(struct ksm memcmp(user->passkey, prev_user->passkey, user->passkey_sz)) goto out;
+ ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_RECONNECT); + err = ksmbd_conn_wait_idle_sess_id(conn, id); + if (err) { + ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_NEGOTIATE); + goto out; + } ksmbd_destroy_file_table(&prev_sess->file_table); prev_sess->state = SMB2_SESSION_EXPIRED; + ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_NEGOTIATE); out: up_write(&conn->session_lock); up_write(&sessions_table_lock); --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2210,7 +2210,7 @@ int smb2_session_logoff(struct ksmbd_wor ksmbd_conn_unlock(conn);
ksmbd_close_session_fds(work); - ksmbd_conn_wait_idle(conn, sess_id); + ksmbd_conn_wait_idle(conn);
/* * Re-lookup session to validate if session is deleted