Patch "ravb: Fix use-after-free issue in ravb_tx_timeout_work()" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ravb: Fix use-after-free issue in ravb_tx_timeout_work()

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ravb-fix-use-after-free-issue-in-ravb_tx_timeout_wor.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c2873350b75a60a06dbbb019bb57ca0cedc53d97
Author: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Date:   Thu Oct 5 10:12:01 2023 +0900

    ravb: Fix use-after-free issue in ravb_tx_timeout_work()
    
    [ Upstream commit 3971442870713de527684398416970cf025b4f89 ]
    
    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@xxxxxxx>
    Closes: https://lore.kernel.org/netdev/20230725030026.1664873-1-zyytlz.wz@xxxxxxx/
    Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
    Reviewed-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
    Link: https://lore.kernel.org/r/20231005011201.14368-3-yoshihiro.shimoda.uh@xxxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index a866a38ebea55..19733c9a7c25e 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1774,6 +1774,8 @@ 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);