From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> Connections may be cleanup while waiting for the commands to complete so this attempts to check if the connection handle remains valid in case of errors that would lead to call hci_conn_failed: BUG: KASAN: slab-use-after-free in hci_conn_failed+0x1f/0x160 Read of size 8 at addr ffff888001376958 by task kworker/u3:0/52 CPU: 0 PID: 52 Comm: kworker/u3:0 Not tainted 6.5.0-rc1-00527-g2dfe76d58d3a #5615 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: hci0 hci_cmd_sync_work Call Trace: <TASK> dump_stack_lvl+0x1d/0x70 print_report+0xce/0x620 ? __virt_addr_valid+0xd4/0x150 ? hci_conn_failed+0x1f/0x160 kasan_report+0xd1/0x100 ? hci_conn_failed+0x1f/0x160 hci_conn_failed+0x1f/0x160 hci_abort_conn_sync+0x237/0x360 Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> --- net/bluetooth/hci_sync.c | 44 +++++++++++++++++++++++++--------------- 1 file changed, 28 insertions(+), 16 deletions(-) diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index 420d25cce2b0..f7908044b411 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -5385,25 +5385,17 @@ static int hci_reject_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason) { - int err; + int err = 0; + u16 handle = conn->handle; switch (conn->state) { case BT_CONNECTED: case BT_CONFIG: - return hci_disconnect_sync(hdev, conn, reason); + err = hci_disconnect_sync(hdev, conn, reason); + break; case BT_CONNECT: err = hci_connect_cancel_sync(hdev, conn, reason); - /* Cleanup hci_conn object if it cannot be cancelled as it - * likelly means the controller and host stack are out of sync - * or in case of LE it was still scanning so it can be cleanup - * safely. - */ - if (err) { - hci_dev_lock(hdev); - hci_conn_failed(conn, err); - hci_dev_unlock(hdev); - } - return err; + break; case BT_CONNECT2: return hci_reject_conn_sync(hdev, conn, reason); case BT_OPEN: @@ -5413,13 +5405,33 @@ int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason) hci_conn_failed(conn, reason); hci_dev_unlock(hdev); } - break; + return 0; default: conn->state = BT_CLOSED; - break; + return 0; } - return 0; + /* Cleanup hci_conn object if it cannot be cancelled as it + * likelly means the controller and host stack are out of sync + * or in case of LE it was still scanning so it can be cleanup + * safely. + */ + if (err) { + struct hci_conn *c; + + /* Check if the connection hasn't been cleanup while waiting + * commands to complete. + */ + c = hci_conn_hash_lookup_handle(hdev, handle); + if (!c || c != conn) + return 0; + + hci_dev_lock(hdev); + hci_conn_failed(conn, err); + hci_dev_unlock(hdev); + } + + return err; } static int hci_disconnect_all_sync(struct hci_dev *hdev, u8 reason) -- 2.41.0