From: Zheng Wang <zyytlz.wz@163.com>
To: timur@kernel.org
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, hackerzheng666@gmail.com,
1395428693sheep@gmail.com, alex000young@gmail.com,
Zheng Wang <zyytlz.wz@163.com>
Subject: [PATCH net v2] net: qcom/emac: Fix use after free bug in emac_remove due to race condition
Date: Sat, 18 Mar 2023 16:05:26 +0800 [thread overview]
Message-ID: <20230318080526.785457-1-zyytlz.wz@163.com> (raw)
In emac_probe, &adpt->work_thread is bound with
emac_work_thread. Then it will be started by timeout
handler emac_tx_timeout or a IRQ handler emac_isr.
If we remove the driver which will call emac_remove
to make cleanup, there may be a unfinished work.
The possible sequence is as follows:
Fix it by finishing the work before cleanup in the emac_remove
and disable timeout response.
CPU0 CPU1
|emac_work_thread
emac_remove |
free_netdev |
kfree(netdev); |
|emac_reinit_locked
|emac_mac_down
|//use netdev
Fixes: b9b17debc69d ("net: emac: emac gigabit ethernet controller driver")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
---
v2:
- cancel the work after unregister_netdev suggested by Jakub
---
drivers/net/ethernet/qualcomm/emac/emac.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/net/ethernet/qualcomm/emac/emac.c b/drivers/net/ethernet/qualcomm/emac/emac.c
index 3115b2c12898..eaa50050aa0b 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac.c
@@ -724,9 +724,15 @@ static int emac_remove(struct platform_device *pdev)
struct net_device *netdev = dev_get_drvdata(&pdev->dev);
struct emac_adapter *adpt = netdev_priv(netdev);
+ netif_carrier_off(netdev);
+ netif_tx_disable(netdev);
+
unregister_netdev(netdev);
netif_napi_del(&adpt->rx_q.napi);
+ free_irq(adpt->irq.irq, &adpt->irq);
+ cancel_work_sync(&adpt->work_thread);
+
emac_clks_teardown(adpt);
put_device(&adpt->phydev->mdio.dev);
--
2.25.1
next reply other threads:[~2023-03-18 8:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-18 8:05 Zheng Wang [this message]
2023-03-20 9:20 ` [PATCH net v2] net: qcom/emac: Fix use after free bug in emac_remove due to race condition patchwork-bot+netdevbpf
2023-03-20 19:22 ` Jakub Kicinski
2023-03-23 3:49 ` Zheng Hacker
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