From 3971442870713de527684398416970cf025b4f89 Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Thu, 5 Oct 2023 10:12:01 +0900
Subject: [PATCH 2/2] ravb: Fix use-after-free issue in ravb_tx_timeout_work()
Git-commit: 3971442870713de527684398416970cf025b4f89
Patch-mainline: v6.6-rc6
References: bsc#1212514 CVE-2023-35827 CVE-2023-52509 bsc#1220836

The ravb_stop() should call cancel_work_sync(). Otherwise,
ravb_tx_timeout_work() is possible to use the freed priv after
ravb_remove() was called like below:

CPU0			CPU1
			ravb_tx_timeout()
ravb_remove()
unregister_netdev()
free_netdev(ndev)
// free priv
			ravb_tx_timeout_work()
			// use priv

unregister_netdev() will call .ndo_stop() so that ravb_stop() is
called. And, after phy_stop() is called, netif_carrier_off()
is also called. So that .ndo_tx_timeout() will not be called
after phy_stop().

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Reported-by: Zheng Wang <zyytlz.wz@163.com>
Closes: https://lore.kernel.org/netdev/20230725030026.1664873-1-zyytlz.wz@163.com/
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/20231005011201.14368-3-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Vasant Karasulli <vkarasulli@suse.de>

---
 drivers/net/ethernet/renesas/ravb_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 9e2e801049cc..0ef0b88b7145 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2167,6 +2167,8 @@ static int ravb_close(struct net_device *ndev)
 			of_phy_deregister_fixed_link(np);
 	}

+	cancel_work_sync(&priv->work);
+
 	if (info->multi_irqs) {
 		free_irq(priv->tx_irqs[RAVB_NC], ndev);
 		free_irq(priv->rx_irqs[RAVB_NC], ndev);
--
2.34.1