From 7c35b3f5e2a0f98dfd0ec9468f85247ca6f01bad 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() 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/atm/nicstar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/atm/nicstar.c b/drivers/atm/nicstar.c index 5c7e4df159b91..b015c3e143361 100644 --- a/drivers/atm/nicstar.c +++ b/drivers/atm/nicstar.c @@ -299,7 +299,7 @@ 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); -- 2.39.5