Commit 8053fc3d authored Nov 26, 2007 by Herbert Xu

[IPSEC]: Temporarily remove locks around copying of non-atomic fields



The change 050f009e

	[IPSEC]: Lock state when copying non-atomic fields to user-space

caused a regression.

Ingo Molnar reports that it causes a potential dead-lock found by the
lock validator as it tries to take x->lock within xfrm_state_lock while
numerous other sites take the locks in opposite order.

For 2.6.24, the best fix is to simply remove the added locks as that puts
us back in the same state as we've been in for years.  For later kernels
a proper fix would be to reverse the locking order for every xfrm state
user such that if x->lock is taken together with xfrm_state_lock then
it is to be taken within it.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

parent 7f9c33e5

net/key/af_key.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -1015,9 +1015,7 @@ static inline struct sk_buff pfkey_xfrm_state2msg(struct xfrm_state x)
		{
		struct sk_buff *skb;

		spin_lock_bh(&x->lock);
		skb = __pfkey_xfrm_state2msg(x, 1, 3);
		spin_unlock_bh(&x->lock);

		return skb;
		}

net/xfrm/xfrm_user.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -507,7 +507,6 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
		struct xfrm_usersa_info *p,
		struct sk_buff *skb)
		{
		spin_lock_bh(&x->lock);
		copy_to_user_state(x, p);

		if (x->coaddr)
		@@ -515,7 +514,6 @@ static int copy_to_user_state_extra(struct xfrm_state *x,

		if (x->lastused)
		NLA_PUT_U64(skb, XFRMA_LASTUSED, x->lastused);
		spin_unlock_bh(&x->lock);

		if (x->aalg)
		NLA_PUT(skb, XFRMA_ALG_AUTH, alg_len(x->aalg), x->aalg);

Admin message