Commit 3a9016f9 authored Feb 19, 2014 by Steffen Klassert

xfrm: Fix unlink race when policies are deleted.



When a policy is unlinked from the lists in thread context,
the xfrm timer can fire before we can mark this policy as dead.
So reinitialize the bydst hlist, then hlist_unhashed() will
notice that this policy is not linked and will avoid a
doulble unlink of that policy.

Reported-by: Xianpeng Zhao <673321875@qq.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

parent ee5c2317

net/xfrm/xfrm_policy.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1158,7 +1158,7 @@ static struct xfrm_policy __xfrm_policy_unlink(struct xfrm_policy pol,
		if (hlist_unhashed(&pol->bydst))
		return NULL;

		hlist_del(&pol->bydst);
		hlist_del_init(&pol->bydst);
		hlist_del(&pol->byidx);
		list_del(&pol->walk.all);
		net->xfrm.policy_count[dir]--;