From 1bdcec8a5f05445752a0639edd603ac09ae6c553 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Fri, 13 May 2016 13:55:21 +0200 Subject: [PATCH] hv_netvsc: use start_remove flag to protect netvsc_link_change() netvsc_link_change() can race with netvsc_change_mtu() or netvsc_set_channels() as these functions destroy struct netvsc_device and rndis filter. Use start_remove flag for syncronization. As netvsc_change_mtu()/netvsc_set_channels() are called with rtnl lock held we need to take it before checking start_remove value in netvsc_link_change(). Reported-by: Haiyang Zhang Signed-off-by: Vitaly Kuznetsov Signed-off-by: David S. Miller --- drivers/net/hyperv/netvsc_drv.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index b3fa2cdcb3f6..01de2dcef170 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -838,6 +838,8 @@ static int netvsc_set_channels(struct net_device *net, out: netvsc_open(net); net_device_ctx->start_remove = false; + /* We may have missed link change notifications */ + schedule_delayed_work(&net_device_ctx->dwork, 0); return ret; @@ -946,6 +948,9 @@ out: netvsc_open(ndev); ndevctx->start_remove = false; + /* We may have missed link change notifications */ + schedule_delayed_work(&ndevctx->dwork, 0); + return ret; } @@ -1066,6 +1071,11 @@ static void netvsc_link_change(struct work_struct *w) unsigned long flags, next_reconfig, delay; ndev_ctx = container_of(w, struct net_device_context, dwork.work); + + rtnl_lock(); + if (ndev_ctx->start_remove) + goto out_unlock; + net_device = hv_get_drvdata(ndev_ctx->device_ctx); rdev = net_device->extension; net = net_device->ndev; @@ -1079,7 +1089,7 @@ static void netvsc_link_change(struct work_struct *w) delay = next_reconfig - jiffies; delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT; schedule_delayed_work(&ndev_ctx->dwork, delay); - return; + goto out_unlock; } ndev_ctx->last_reconfig = jiffies; @@ -1093,9 +1103,7 @@ static void netvsc_link_change(struct work_struct *w) spin_unlock_irqrestore(&ndev_ctx->lock, flags); if (!event) - return; - - rtnl_lock(); + goto out_unlock; switch (event->event) { /* Only the following events are possible due to the check in @@ -1144,6 +1152,11 @@ static void netvsc_link_change(struct work_struct *w) */ if (reschedule) schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT); + + return; + +out_unlock: + rtnl_unlock(); } static void netvsc_free_netdev(struct net_device *netdev) -- 2.20.1