Messages in this thread Patch in this message | | | From | Zheng Wang <> | Subject | [PATCH net] net: qcom/emac: Fix use after free bug in emac_remove due to race condition | Date | Fri, 10 Mar 2023 18:57:34 +0800 |
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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> --- drivers/net/ethernet/qualcomm/emac/emac.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/ethernet/qualcomm/emac/emac.c b/drivers/net/ethernet/qualcomm/emac/emac.c index 3115b2c12898..ddc328f7b96a 100644 --- a/drivers/net/ethernet/qualcomm/emac/emac.c +++ b/drivers/net/ethernet/qualcomm/emac/emac.c @@ -724,6 +724,9 @@ 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); + cancel_work_sync(&adpt->work_thread); unregister_netdev(netdev); netif_napi_del(&adpt->rx_q.napi); -- 2.25.1
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