From f56446ba5378d19e31040b548a14ee9a8f1500ea Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sat, 2 Nov 2024 18:46:38 +0900 Subject: [PATCH] ksmbd: fix slab-use-after-free in ksmbd_smb2_session_create 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 Tested-by: Norbert Szetei Signed-off-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/server/mgmt/user_session.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/smb/server/mgmt/user_session.c b/fs/smb/server/mgmt/user_session.c index 844db95e6651..0cbcf8bf905f 100644 --- 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 ksmbd_conn *conn) 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 ksmbd_conn *conn) } } 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 ksmbd_conn *conn) } } } - 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 ksmbd_conn *conn) } } up_write(&conn->session_lock); + up_write(&sessions_table_lock); } struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn,