Commit ce7ea4af authored Sep 18, 2018 by Wei Wang Committed by David S. Miller Sep 18, 2018

ipv6: fix memory leak on dst->_metrics



When dst->_metrics and f6i->fib6_metrics share the same memory, both
take reference count on the dst_metrics structure. However, when dst is
destroyed, ip6_dst_destroy() only invokes dst_destroy_metrics_generic()
which does not take care of READONLY metrics and does not release refcnt.
This causes memory leak.
Similar to ipv4 logic, the fix is to properly release refcnt and free
the memory space pointed by dst->_metrics if refcnt becomes 0.

Fixes: 93531c67 ("net/ipv6: separate handling of FIB entries from dst based routes")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 86758605

net/ipv6/route.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -364,11 +364,14 @@ EXPORT_SYMBOL(ip6_dst_alloc);

		static void ip6_dst_destroy(struct dst_entry *dst)
		{
		struct dst_metrics p = (struct dst_metrics )DST_METRICS_PTR(dst);
		struct rt6_info rt = (struct rt6_info )dst;
		struct fib6_info *from;
		struct inet6_dev *idev;

		dst_destroy_metrics_generic(dst);
		if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
		kfree(p);

		rt6_uncached_list_del(rt);

		idev = rt->rt6i_idev;

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