From e3583d7b1bd9869c371aa1164a085e0966a86391 Mon Sep 17 00:00:00 2001 From: Hermes Zhang Date: Tue, 28 Aug 2018 09:48:30 +0800 Subject: [PATCH] Bluetooth: hci_ldisc: Free rw_semaphore on close [ 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: [] debug_print_object+0xac/0xc8 [] debug_check_no_obj_freed+0x1e8/0x228 [] kfree+0x1cc/0x250 [] hci_uart_tty_close+0x54/0x108 [] tty_ldisc_close.isra.1+0x40/0x58 [] tty_ldisc_kill+0x1c/0x40 [] tty_ldisc_release+0x94/0x170 [] tty_release_struct+0x1c/0x58 [] tty_release+0x3b0/0x490 [] __fput+0x88/0x1d0 [] ____fput+0xc/0x18 [] task_work_run+0x9c/0xc0 [] do_exit+0x24c/0x8a0 [] do_group_exit+0x38/0xa0 [] __wake_up_parent+0x0/0x28 [] el0_svc_naked+0x34/0x38 ---[ end trace bfe08cbd89098cdf ]--- Signed-off-by: Hermes Zhang Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- 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 c823914b3a80..30bbe19b4b85 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -539,6 +539,8 @@ 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); }