From: Zheng Wang Date: Sat, 18 Mar 2023 08:05:26 +0000 (+0800) Subject: net: qcom/emac: Fix use after free bug in emac_remove due to race condition X-Git-Tag: baikal/mips/sdk5.8.2~93 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=d64928d328fbd79e1ce287dceb125e8b0c72fd23;p=kernel.git net: qcom/emac: Fix use after free bug in emac_remove due to race condition [ Upstream commit 6b6bc5b8bd2d4ca9e1efa9ae0f98a0b0687ace75 ] 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: 537813f6160a ("net: emac: emac gigabit ethernet controller driver") Signed-off-by: Zheng Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- diff --git a/drivers/net/ethernet/qualcomm/emac/emac.c b/drivers/net/ethernet/qualcomm/emac/emac.c index 5c199d2516d47..5fe28dec60c1d 100644 --- a/drivers/net/ethernet/qualcomm/emac/emac.c +++ b/drivers/net/ethernet/qualcomm/emac/emac.c @@ -738,9 +738,15 @@ 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);