Commit 1caf2729 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

ipv6: adopt dst_dev() helper 



Use the new helper as a step to deal with potential dst->dev races.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-9-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a74fc62e

include/net/ip6_route.h

+2 −2
Original line number Diff line number Diff line
@@ -274,7 +274,7 @@ static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb) 
	unsigned int mtu;



	if (np && READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE) {

		mtu = READ_ONCE(dst->dev->mtu);

		mtu = READ_ONCE(dst_dev(dst)->mtu);

		mtu -= lwtunnel_headroom(dst->lwtstate, mtu);

	} else {

		mtu = dst_mtu(dst);
@@ -337,7 +337,7 @@ static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst 


	mtu = IPV6_MIN_MTU;

	rcu_read_lock();

	idev = __in6_dev_get(dst->dev);

	idev = __in6_dev_get(dst_dev(dst));

	if (idev)

		mtu = READ_ONCE(idev->cnf.mtu6);

	rcu_read_unlock();

net/ipv6/exthdrs.c

+1 −1
Original line number Diff line number Diff line
@@ -306,7 +306,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb) 
	if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||

	    !pskb_may_pull(skb, (skb_transport_offset(skb) +

				 ((skb_transport_header(skb)[1] + 1) << 3)))) {

		__IP6_INC_STATS(dev_net(dst->dev), idev,

		__IP6_INC_STATS(dev_net(dst_dev(dst)), idev,

				IPSTATS_MIB_INHDRERRORS);

fail_and_free:

		kfree_skb(skb);

net/ipv6/icmp.c

+3 −1
Original line number Diff line number Diff line
@@ -196,6 +196,7 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, 
			       struct flowi6 *fl6, bool apply_ratelimit)

{

	struct net *net = sock_net(sk);

	struct net_device *dev;

	struct dst_entry *dst;

	bool res = false;
@@ -208,10 +209,11 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, 
	 * this lookup should be more aggressive (not longer than timeout).

	 */

	dst = ip6_route_output(net, sk, fl6);

	dev = dst_dev(dst);

	if (dst->error) {

		IP6_INC_STATS(net, ip6_dst_idev(dst),

			      IPSTATS_MIB_OUTNOROUTES);

	} else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {

	} else if (dev && (dev->flags & IFF_LOOPBACK)) {

		res = true;

	} else {

		struct rt6_info *rt = dst_rt6_info(dst);

net/ipv6/ila/ila_lwt.c

+1 −1
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb) 
		 */



		memset(&fl6, 0, sizeof(fl6));

		fl6.flowi6_oif = orig_dst->dev->ifindex;

		fl6.flowi6_oif = dst_dev(orig_dst)->ifindex;

		fl6.flowi6_iif = LOOPBACK_IFINDEX;

		fl6.daddr = *rt6_nexthop(dst_rt6_info(orig_dst),

					 &ip6h->daddr);

net/ipv6/ioam6_iptunnel.c

+2 −2
Original line number Diff line number Diff line
@@ -335,7 +335,7 @@ static int ioam6_do_encap(struct net *net, struct sk_buff *skb, 
	if (has_tunsrc)

		memcpy(&hdr->saddr, tunsrc, sizeof(*tunsrc));

	else

		ipv6_dev_get_saddr(net, dst->dev, &hdr->daddr,

		ipv6_dev_get_saddr(net, dst_dev(dst), &hdr->daddr,

				   IPV6_PREFER_SRC_PUBLIC, &hdr->saddr);



	skb_postpush_rcsum(skb, hdr, len);
@@ -442,7 +442,7 @@ static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb) 
			dst_cache_set_ip6(&ilwt->cache, dst, &fl6.saddr);

		local_bh_enable();



		err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));

		err = skb_cow_head(skb, LL_RESERVED_SPACE(dst_dev(dst)));

		if (unlikely(err))

			goto drop;

	}