Commit 64327fc8 authored Aug 31, 2017 by Stefano Brivio Committed by David S. Miller Sep 03, 2017

ipv4: Don't override return code from ip_route_input_noref()



After ip_route_input() calls ip_route_input_noref(), another
check on skb_dst() is done, but if this fails, we shouldn't
override the return code from ip_route_input_noref(), as it
could have been more specific (i.e. -EHOSTUNREACH).

This also saves one call to skb_dst_force_safe() and one to
skb_dst() in case the ip_route_input_noref() check fails.

Reported-by: Sabrina Dubroca <sdubroca@redhat.com>
Fixes: 9df16efa ("ipv4: call dst_hold_safe() properly")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Wei Wang <weiwan@google.com>
Acked-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 138e4ad6

include/net/route.h

+4 −3

Original line number	Diff line number	Diff line
		@@ -189,10 +189,11 @@ static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,

		rcu_read_lock();
		err = ip_route_input_noref(skb, dst, src, tos, devin);
		if (!err)
		if (!err) {
		skb_dst_force_safe(skb);
		if (!skb_dst(skb))
		err = -EINVAL;
		}
		rcu_read_unlock();

		return err;

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