From: Chen Junlin chen.junlin@zte.com.cn
Although the upstream commit 2b0f2fc9ed62 ("Bluetooth: hci_conn: Use disable_delayed_work_sync") has fixed the issue CVE-2024-56591, that patch depends on the implementaion of disable/enable_work() of workqueue [1], which are merged into 6.9/6.10 and so on. But for branch linux-6.6, there's no these feature of workqueue.
To solve CVE-2024-56591 without backport too many feature patches about workqueue, we can set a new flag HCI_CONN_DELETE when hci_conn_dell() is called, and the subsequent queuing of work will be ignored.
[1] https://lore.kernel.org/all/20240216180559.208276-1-tj@kernel.org/
Signed-off-by: Chen Junlin chen.junlin@zte.com.cn Signed-off-by: xu xin xu.xin16@zte.com.cn --- include/net/bluetooth/hci_core.h | 8 +++++++- net/bluetooth/hci_conn.c | 1 + 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index 4f067599e6e9..9a3ec55079a1 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -954,6 +954,7 @@ enum { HCI_CONN_BIG_SYNC_FAILED, HCI_CONN_PA_SYNC, HCI_CONN_PA_SYNC_FAILED, + HCI_CONN_DELETE, };
static inline bool hci_conn_ssp_enabled(struct hci_conn *conn) @@ -1575,7 +1576,12 @@ static inline void hci_conn_drop(struct hci_conn *conn) }
cancel_delayed_work(&conn->disc_work); - queue_delayed_work(conn->hdev->workqueue, + /* + * When HCI_CONN_DELETE is set, the conn is goint to be freed. + * Don't queue the work to avoid noisy WARNing about refcnt < 0. + */ + if (!test_bit(HCI_CONN_DELETE, &conn->flags)) + queue_delayed_work(conn->hdev->workqueue, &conn->disc_work, timeo); } } diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 549ee9e87d63..67a6513bb01c 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -1112,6 +1112,7 @@ void hci_conn_del(struct hci_conn *conn)
hci_conn_unlink(conn);
+ set_bit(HCI_CONN_DELETE, &conn->flags); cancel_delayed_work_sync(&conn->disc_work); cancel_delayed_work_sync(&conn->auto_accept_work); cancel_delayed_work_sync(&conn->idle_work); -- 2.15.2