From 009fc857c5f6fda81f2f7dd851b2d54193a8e733 Mon Sep 17 00:00:00 2001 From: Zou Wei Date: Tue, 11 May 2021 14:58:53 +0800 Subject: mISDN: fix possible use-after-free in HFC_cleanup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself. Reported-by: Hulk Robot Signed-off-by: Zou Wei Signed-off-by: David S. Miller --- drivers/isdn/hardware/mISDN/hfcpci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/isdn') diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c index 56bd2e9db6ed..e501cb03f211 100644 --- a/drivers/isdn/hardware/mISDN/hfcpci.c +++ b/drivers/isdn/hardware/mISDN/hfcpci.c @@ -2342,7 +2342,7 @@ static void __exit HFC_cleanup(void) { if (timer_pending(&hfc_tl)) - del_timer(&hfc_tl); + del_timer_sync(&hfc_tl); pci_unregister_driver(&hfc_driver); } -- cgit