From: Zou Wei zou_wei@huawei.com
stable inclusion from linux-4.19.198 commit 5f2818185da0fe82a932f0856633038b66faf124
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[ Upstream commit 009fc857c5f6fda81f2f7dd851b2d54193a8e733 ]
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/isdn/hardware/mISDN/hfcpci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c index ebb3fa2e1d00f..53349850f8669 100644 --- a/drivers/isdn/hardware/mISDN/hfcpci.c +++ b/drivers/isdn/hardware/mISDN/hfcpci.c @@ -2348,7 +2348,7 @@ 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); }