From 4e2a0848ea2cab0716d46f85a8ccd5fa9a493e51 Mon Sep 17 00:00:00 2001 From: Zou Wei Date: Wed, 12 May 2021 15:00:24 +0800 Subject: [PATCH] atm: nicstar: Fix possible use-after-free in nicstar_cleanup() [ Upstream commit 34e7434ba4e97f4b85c1423a59b2922ba7dff2ea ] 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 Signed-off-by: Sasha Levin --- drivers/atm/nicstar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/atm/nicstar.c b/drivers/atm/nicstar.c index 8bcd09fb0feb..b2bae94ffe4d 100644 --- a/drivers/atm/nicstar.c +++ b/drivers/atm/nicstar.c @@ -298,7 +298,7 @@ static void __exit nicstar_cleanup(void) { XPRINTK("nicstar: nicstar_cleanup() called.\n"); - del_timer(&ns_timer); + del_timer_sync(&ns_timer); pci_unregister_driver(&nicstar_driver);