From: Zou Wei zou_wei@huawei.com
stable inclusion from linux-4.19.198 commit a7a7b2848312cc4c3a42b6e42a8ab2e441857aba
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[ 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 hulkci@huawei.com Signed-off-by: Zou Wei zou_wei@huawei.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- 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 0d3754a4ac209..5281db3d67836 100644 --- a/drivers/atm/nicstar.c +++ b/drivers/atm/nicstar.c @@ -296,7 +296,7 @@ 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);