From: Hermes Zhang <chenhuiz@xxxxxxxx> [ Upstream commit e6a57d22f787e73635ce0d29eef0abb77928b3e9 ] The percpu_rw_semaphore is not currently freed, and this leads to a crash when the stale rcu callback is invoked. DEBUG_OBJECTS detects this. ODEBUG: free active (active state 1) object type: rcu_head hint: (null) ------------[ cut here ]------------ WARNING: CPU: 1 PID: 2024 at debug_print_object+0xac/0xc8 PC is at debug_print_object+0xac/0xc8 LR is at debug_print_object+0xac/0xc8 Call trace: [<ffffff80082e2c2c>] debug_print_object+0xac/0xc8 [<ffffff80082e40b0>] debug_check_no_obj_freed+0x1e8/0x228 [<ffffff8008191254>] kfree+0x1cc/0x250 [<ffffff80083cc03c>] hci_uart_tty_close+0x54/0x108 [<ffffff800832e118>] tty_ldisc_close.isra.1+0x40/0x58 [<ffffff800832e14c>] tty_ldisc_kill+0x1c/0x40 [<ffffff800832e3dc>] tty_ldisc_release+0x94/0x170 [<ffffff8008325554>] tty_release_struct+0x1c/0x58 [<ffffff8008326400>] tty_release+0x3b0/0x490 [<ffffff80081a3fe8>] __fput+0x88/0x1d0 [<ffffff80081a418c>] ____fput+0xc/0x18 [<ffffff80080c0624>] task_work_run+0x9c/0xc0 [<ffffff80080a9e24>] do_exit+0x24c/0x8a0 [<ffffff80080aa4e0>] do_group_exit+0x38/0xa0 [<ffffff80080aa558>] __wake_up_parent+0x0/0x28 [<ffffff8008082c00>] el0_svc_naked+0x34/0x38 ---[ end trace bfe08cbd89098cdf ]--- Signed-off-by: Hermes Zhang <chenhuiz@xxxxxxxx> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- drivers/bluetooth/hci_ldisc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index 963bb0309e25..ea6238ed5c0e 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -543,6 +543,8 @@ static void hci_uart_tty_close(struct tty_struct *tty) } clear_bit(HCI_UART_PROTO_SET, &hu->flags); + percpu_free_rwsem(&hu->proto_lock); + kfree(hu); } -- 2.17.1
