Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 57c5d461 authored by Amerigo Wang's avatar Amerigo Wang Committed by David S. Miller
Browse files

netpoll: take rcu_read_lock_bh() in netpoll_rx() 



In __netpoll_rx(), it dereferences ->npinfo without rcu_dereference_bh(),
this patch fixes it by using the 'npinfo' passed from netpoll_rx()
where it is already dereferenced with rcu_dereference_bh().

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: default avatarCong Wang <amwang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3335f0ca

include/linux/netpoll.h

+2 −2
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ void netpoll_set_trap(int trap); 
void __netpoll_cleanup(struct netpoll *np);

void __netpoll_free_rcu(struct netpoll *np);

void netpoll_cleanup(struct netpoll *np);

int __netpoll_rx(struct sk_buff *skb);

int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);

void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,

			     struct net_device *dev);

static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
@@ -77,7 +77,7 @@ static inline bool netpoll_rx(struct sk_buff *skb) 


	spin_lock(&npinfo->rx_lock);

	/* check rx_flags again with the lock held */

	if (npinfo->rx_flags && __netpoll_rx(skb))

	if (npinfo->rx_flags && __netpoll_rx(skb, npinfo))

		ret = true;

	spin_unlock(&npinfo->rx_lock);

net/core/netpoll.c

+1 −2
Original line number Diff line number Diff line
@@ -543,13 +543,12 @@ static void arp_reply(struct sk_buff *skb) 
	spin_unlock_irqrestore(&npinfo->rx_lock, flags);

}



int __netpoll_rx(struct sk_buff *skb)

int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)

{

	int proto, len, ulen;

	int hits = 0;

	const struct iphdr *iph;

	struct udphdr *uh;

	struct netpoll_info *npinfo = skb->dev->npinfo;

	struct netpoll *np, *tmp;



	if (list_empty(&npinfo->rx_np))