6.6-stable review patch. If anyone has any objections, please let me know.
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From: Namjae Jeon linkinjeon@kernel.org
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@vger.kernel.org # v5.15+ Reported-by: Norbert Szetei norbert@doyensec.com Tested-by: Norbert Szetei norbert@doyensec.com 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/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 @@ -174,6 +174,7 @@ 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 && @@ -187,6 +188,7 @@ static void ksmbd_expire_session(struct } } up_write(&conn->session_lock); + up_write(&sessions_table_lock); }
int ksmbd_session_register(struct ksmbd_conn *conn, @@ -228,7 +230,6 @@ void ksmbd_sessions_deregister(struct ks } } } - up_write(&sessions_table_lock);
down_write(&conn->session_lock); xa_for_each(&conn->sessions, id, sess) { @@ -248,6 +249,7 @@ 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,