6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Namjae Jeon <linkinjeon@xxxxxxxxxx> commit 0a77715db22611df50b178374c51e2ba0d58866e upstream. There is a race condition between ksmbd_smb2_session_create and ksmbd_expire_session. This patch add missing sessions_table_lock while adding/deleting session from global session table. Cc: stable@xxxxxxxxxxxxxxx # v5.15+ Reported-by: Norbert Szetei <norbert@xxxxxxxxxxxx> Tested-by: Norbert Szetei <norbert@xxxxxxxxxxxx> Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/smb/server/mgmt/user_session.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -175,6 +175,7 @@ static void ksmbd_expire_session(struct unsigned long id; struct ksmbd_session *sess; + down_write(&sessions_table_lock); down_write(&conn->session_lock); xa_for_each(&conn->sessions, id, sess) { if (atomic_read(&sess->refcnt) == 0 && @@ -188,6 +189,7 @@ static void ksmbd_expire_session(struct } } up_write(&conn->session_lock); + up_write(&sessions_table_lock); } int ksmbd_session_register(struct ksmbd_conn *conn, @@ -229,7 +231,6 @@ void ksmbd_sessions_deregister(struct ks } } } - up_write(&sessions_table_lock); down_write(&conn->session_lock); xa_for_each(&conn->sessions, id, sess) { @@ -249,6 +250,7 @@ void ksmbd_sessions_deregister(struct ks } } up_write(&conn->session_lock); + up_write(&sessions_table_lock); } struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn,