hsr: use hsr_for_each_port_rtnl in hsr_port_get_hsr

liuhangbin · gregkh · commit dac341e35749 · 2025-09-19T16:35:50.000+02:00
[ Upstream commit 393c841 ] hsr_port_get_hsr() iterates over ports using hsr_for_each_port(), but many of its callers do not hold the required RCU lock. Switch to hsr_for_each_port_rtnl(), since most callers already hold the rtnl lock. After review, all callers are covered by either the rtnl lock or the RCU lock, except hsr_dev_xmit(). Fix this by adding an RCU read lock there. Fixes: c5a7591 ("net/hsr: Use list_head (and rcu) instead of array for slave devices.") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250905091533.377443-3-liuhangbin@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
@@ -226,6 +226,7 @@ static netdev_tx_t hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct hsr_priv *hsr = netdev_priv(dev);
 	struct hsr_port *master;
 
+	rcu_read_lock();
 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 	if (master) {
 		skb->dev = master->dev;
@@ -238,6 +239,8 @@ static netdev_tx_t hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 		dev_core_stats_tx_dropped_inc(dev);
 		dev_kfree_skb_any(skb);
 	}
+	rcu_read_unlock();
+
 	return NETDEV_TX_OK;
 }
 
diff --git a/net/hsr/hsr_main.c b/net/hsr/hsr_main.c
@@ -125,7 +125,7 @@ struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt)
 {
 	struct hsr_port *port;
 
-	hsr_for_each_port(hsr, port)
+	hsr_for_each_port_rtnl(hsr, port)
 		if (port->type == pt)
 			return port;
 	return NULL;

Original file line number	Diff line number	Diff line change
`@@ -226,6 +226,7 @@ static netdev_tx_t hsr_dev_xmit(struct sk_buff skb, struct net_device dev)`
`226`	`226`	`struct hsr_priv *hsr = netdev_priv(dev);`
`227`	`227`	`struct hsr_port *master;`
`228`	`228`
	`229`	`+ rcu_read_lock();`
`229`	`230`	`master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);`
`230`	`231`	`if (master) {`
`231`	`232`	`skb->dev = master->dev;`
`@@ -238,6 +239,8 @@ static netdev_tx_t hsr_dev_xmit(struct sk_buff skb, struct net_device dev)`
`238`	`239`	`dev_core_stats_tx_dropped_inc(dev);`
`239`	`240`	`dev_kfree_skb_any(skb);`
`240`	`241`	`}`
	`242`	`+ rcu_read_unlock();`
	`243`	`+`
`241`	`244`	`return NETDEV_TX_OK;`
`242`	`245`	`}`
`243`	`246`
Original file line number	Diff line number	Diff line change
`@@ -125,7 +125,7 @@ struct hsr_port hsr_port_get_hsr(struct hsr_priv hsr, enum hsr_port_type pt)`
`125`	`125`	`{`
`126`	`126`	`struct hsr_port *port;`
`127`	`127`
`128`		`- hsr_for_each_port(hsr, port)`
	`128`	`+ hsr_for_each_port_rtnl(hsr, port)`
`129`	`129`	`if (port->type == pt)`
`130`	`130`	`return port;`
`131`	`131`	`return NULL;`