[PATCH AUTOSEL 4.4 1/8] net: pxa168_eth: Fix a potential data race in pxa168_eth_remove

Sasha Levin
2021-03-29T22:31:59Z

From: Pavel Andrianov <andrianov@ispras.ru>

[ Upstream commit 0571a753cb07982cc82f4a5115e0b321da89e1f3 ]

pxa168_eth_remove() firstly calls unregister_netdev(),
then cancels a timeout work. unregister_netdev() shuts down a device
interface and removes it from the kernel tables. If the timeout occurs
in parallel, the timeout work (pxa168_eth_tx_timeout_task) performs stop
and open of the device. It may lead to an inconsistent state and memory
leaks.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Pavel Andrianov <andrianov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/marvell/pxa168_eth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/pxa168_eth.c b/drivers/net/ethernet/marvell/pxa168_eth.c
index 7ace07dad6a3..9986f88618bd 100644
--- a/drivers/net/ethernet/marvell/pxa168_eth.c
+++ b/drivers/net/ethernet/marvell/pxa168_eth.c
@@ -1577,8 +1577,8 @@ static int pxa168_eth_remove(struct platform_device *pdev)

mdiobus_unregister(pep->smi_bus);
mdiobus_free(pep->smi_bus);
- unregister_netdev(dev);
cancel_work_sync(&pep->tx_timeout_task);
+ unregister_netdev(dev);
free_netdev(dev);
return 0;
}
--
2.30.1