X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=net%2Fxfrm%2Fxfrm_policy.c;h=b469c8b54613354a495db0fc4996aa5916e53829;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=d07f5ce31824f0f887a737cd544c4dbbb035344b;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index d07f5ce31..b469c8b54 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -10,10 +10,9 @@
  * 	YOSHIFUJI Hideaki
  * 		Split up af-specific portion
  *	Derek Atkins <derek@ihtfp.com>		Add the post_input processor
- * 	
+ *
  */
 
-#include <asm/bug.h>
 #include <linux/config.h>
 #include <linux/slab.h>
 #include <linux/kmod.h>
@@ -22,12 +21,13 @@
 #include <linux/workqueue.h>
 #include <linux/notifier.h>
 #include <linux/netdevice.h>
+#include <linux/netfilter.h>
 #include <linux/module.h>
 #include <net/xfrm.h>
 #include <net/ip.h>
 
-DECLARE_MUTEX(xfrm_cfg_sem);
-EXPORT_SYMBOL(xfrm_cfg_sem);
+DEFINE_MUTEX(xfrm_cfg_mutex);
+EXPORT_SYMBOL(xfrm_cfg_mutex);
 
 static DEFINE_RWLOCK(xfrm_policy_lock);
 
@@ -37,7 +37,7 @@ EXPORT_SYMBOL(xfrm_policy_list);
 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
 
-static kmem_cache_t *xfrm_dst_cache;
+static kmem_cache_t *xfrm_dst_cache __read_mostly;
 
 static struct work_struct xfrm_policy_gc_work;
 static struct list_head xfrm_policy_gc_list =
@@ -57,12 +57,12 @@ int xfrm_register_type(struct xfrm_type *type, unsigned short family)
 		return -EAFNOSUPPORT;
 	typemap = afinfo->type_map;
 
-	write_lock(&typemap->lock);
+	write_lock_bh(&typemap->lock);
 	if (likely(typemap->map[type->proto] == NULL))
 		typemap->map[type->proto] = type;
 	else
 		err = -EEXIST;
-	write_unlock(&typemap->lock);
+	write_unlock_bh(&typemap->lock);
 	xfrm_policy_put_afinfo(afinfo);
 	return err;
 }
@@ -78,12 +78,12 @@ int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
 		return -EAFNOSUPPORT;
 	typemap = afinfo->type_map;
 
-	write_lock(&typemap->lock);
+	write_lock_bh(&typemap->lock);
 	if (unlikely(typemap->map[type->proto] != type))
 		err = -ENOENT;
 	else
 		typemap->map[type->proto] = NULL;
-	write_unlock(&typemap->lock);
+	write_unlock_bh(&typemap->lock);
 	xfrm_policy_put_afinfo(afinfo);
 	return err;
 }
@@ -118,7 +118,6 @@ retry:
 	xfrm_policy_put_afinfo(afinfo);
 	return type;
 }
-EXPORT_SYMBOL(xfrm_get_type);
 
 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, 
 		    unsigned short family)
@@ -164,7 +163,7 @@ static void xfrm_policy_timer(unsigned long data)
 	if (xp->dead)
 		goto out;
 
-	dir = xp->index & 7;
+	dir = xfrm_policy_id2dir(xp->index);
 
 	if (xp->lft.hard_add_expires_seconds) {
 		long tmo = xp->lft.hard_add_expires_seconds +
@@ -204,7 +203,7 @@ static void xfrm_policy_timer(unsigned long data)
 	}
 
 	if (warn)
-		km_policy_expired(xp, dir, 0);
+		km_policy_expired(xp, dir, 0, 0);
 	if (next != LONG_MAX &&
 	    !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 		xfrm_pol_hold(xp);
@@ -216,8 +215,8 @@ out:
 
 expired:
 	read_unlock(&xp->lock);
-	km_policy_expired(xp, dir, 1);
-	xfrm_policy_delete(xp, dir);
+	if (!xfrm_policy_delete(xp, dir))
+		km_policy_expired(xp, dir, 1, 0);
 	xfrm_pol_put(xp);
 }
 
@@ -226,7 +225,7 @@ expired:
  * SPD calls.
  */
 
-struct xfrm_policy *xfrm_policy_alloc(int gfp)
+struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
 {
 	struct xfrm_policy *policy;
 
@@ -248,15 +247,14 @@ EXPORT_SYMBOL(xfrm_policy_alloc);
 
 void __xfrm_policy_destroy(struct xfrm_policy *policy)
 {
-	if (!policy->dead)
-		BUG();
+	BUG_ON(!policy->dead);
 
-	if (policy->bundles)
-		BUG();
+	BUG_ON(policy->bundles);
 
 	if (del_timer(&policy->timer))
 		BUG();
 
+	security_xfrm_policy_free(policy);
 	kfree(policy);
 }
 EXPORT_SYMBOL(__xfrm_policy_destroy);
@@ -347,10 +345,12 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 	struct xfrm_policy *pol, **p;
 	struct xfrm_policy *delpol = NULL;
 	struct xfrm_policy **newpos = NULL;
+	struct dst_entry *gc_list;
 
 	write_lock_bh(&xfrm_policy_lock);
 	for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) {
-		if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0) {
+		if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0 &&
+		    xfrm_sec_ctx_match(pol->security, policy->security)) {
 			if (excl) {
 				write_unlock_bh(&xfrm_policy_lock);
 				return -EEXIST;
@@ -382,21 +382,49 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 		xfrm_pol_hold(policy);
 	write_unlock_bh(&xfrm_policy_lock);
 
-	if (delpol) {
+	if (delpol)
 		xfrm_policy_kill(delpol);
+
+	read_lock_bh(&xfrm_policy_lock);
+	gc_list = NULL;
+	for (policy = policy->next; policy; policy = policy->next) {
+		struct dst_entry *dst;
+
+		write_lock(&policy->lock);
+		dst = policy->bundles;
+		if (dst) {
+			struct dst_entry *tail = dst;
+			while (tail->next)
+				tail = tail->next;
+			tail->next = gc_list;
+			gc_list = dst;
+
+			policy->bundles = NULL;
+		}
+		write_unlock(&policy->lock);
 	}
+	read_unlock_bh(&xfrm_policy_lock);
+
+	while (gc_list) {
+		struct dst_entry *dst = gc_list;
+
+		gc_list = dst->next;
+		dst_free(dst);
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(xfrm_policy_insert);
 
-struct xfrm_policy *xfrm_policy_bysel(int dir, struct xfrm_selector *sel,
-				      int delete)
+struct xfrm_policy *xfrm_policy_bysel_ctx(int dir, struct xfrm_selector *sel,
+					  struct xfrm_sec_ctx *ctx, int delete)
 {
 	struct xfrm_policy *pol, **p;
 
 	write_lock_bh(&xfrm_policy_lock);
 	for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
-		if (memcmp(sel, &pol->selector, sizeof(*sel)) == 0) {
+		if ((memcmp(sel, &pol->selector, sizeof(*sel)) == 0) &&
+		    (xfrm_sec_ctx_match(ctx, pol->security))) {
 			xfrm_pol_hold(pol);
 			if (delete)
 				*p = pol->next;
@@ -411,14 +439,14 @@ struct xfrm_policy *xfrm_policy_bysel(int dir, struct xfrm_selector *sel,
 	}
 	return pol;
 }
-EXPORT_SYMBOL(xfrm_policy_bysel);
+EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 
 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete)
 {
 	struct xfrm_policy *pol, **p;
 
 	write_lock_bh(&xfrm_policy_lock);
-	for (p = &xfrm_policy_list[id & 7]; (pol=*p)!=NULL; p = &pol->next) {
+	for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
 		if (pol->index == id) {
 			xfrm_pol_hold(pol);
 			if (delete)
@@ -492,7 +520,7 @@ EXPORT_SYMBOL(xfrm_policy_walk);
 
 /* Find policy to apply to this flow. */
 
-static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
+static void xfrm_policy_lookup(struct flowi *fl, u32 sk_sid, u16 family, u8 dir,
 			       void **objp, atomic_t **obj_refp)
 {
 	struct xfrm_policy *pol;
@@ -506,9 +534,12 @@ static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
 			continue;
 
 		match = xfrm_selector_match(sel, fl, family);
+
 		if (match) {
-			xfrm_pol_hold(pol);
-			break;
+ 			if (!security_xfrm_policy_lookup(pol, sk_sid, dir)) {
+				xfrm_pol_hold(pol);
+				break;
+			}
 		}
 	}
 	read_unlock_bh(&xfrm_policy_lock);
@@ -516,15 +547,37 @@ static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
 		*obj_refp = &pol->refcnt;
 }
 
-static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
+static inline int policy_to_flow_dir(int dir)
+{
+	if (XFRM_POLICY_IN == FLOW_DIR_IN &&
+ 	    XFRM_POLICY_OUT == FLOW_DIR_OUT &&
+ 	    XFRM_POLICY_FWD == FLOW_DIR_FWD)
+ 		return dir;
+ 	switch (dir) {
+ 	default:
+ 	case XFRM_POLICY_IN:
+ 		return FLOW_DIR_IN;
+ 	case XFRM_POLICY_OUT:
+ 		return FLOW_DIR_OUT;
+ 	case XFRM_POLICY_FWD:
+ 		return FLOW_DIR_FWD;
+	};
+}
+
+static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl, u32 sk_sid)
 {
 	struct xfrm_policy *pol;
 
 	read_lock_bh(&xfrm_policy_lock);
 	if ((pol = sk->sk_policy[dir]) != NULL) {
-		int match = xfrm_selector_match(&pol->selector, fl,
+ 		int match = xfrm_selector_match(&pol->selector, fl,
 						sk->sk_family);
+ 		int err = 0;
+
 		if (match)
+		  err = security_xfrm_policy_lookup(pol, sk_sid, policy_to_flow_dir(dir));
+
+ 		if (match && !err)
 			xfrm_pol_hold(pol);
 		else
 			pol = NULL;
@@ -555,7 +608,7 @@ static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 	return NULL;
 }
 
-void xfrm_policy_delete(struct xfrm_policy *pol, int dir)
+int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
 {
 	write_lock_bh(&xfrm_policy_lock);
 	pol = __xfrm_policy_unlink(pol, dir);
@@ -564,8 +617,11 @@ void xfrm_policy_delete(struct xfrm_policy *pol, int dir)
 		if (dir < XFRM_POLICY_MAX)
 			atomic_inc(&flow_cache_genid);
 		xfrm_policy_kill(pol);
+		return 0;
 	}
+	return -ENOENT;
 }
+EXPORT_SYMBOL(xfrm_policy_delete);
 
 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
 {
@@ -595,6 +651,10 @@ static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
 
 	if (newp) {
 		newp->selector = old->selector;
+		if (security_xfrm_policy_clone(old, newp)) {
+			kfree(newp);
+			return NULL;  /* ENOMEM */
+		}
 		newp->lft = old->lft;
 		newp->curlft = old->curlft;
 		newp->action = old->action;
@@ -706,22 +766,6 @@ xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
 	return err;
 }
 
-static inline int policy_to_flow_dir(int dir)
-{
-	if (XFRM_POLICY_IN == FLOW_DIR_IN &&
-	    XFRM_POLICY_OUT == FLOW_DIR_OUT &&
-	    XFRM_POLICY_FWD == FLOW_DIR_FWD)
-		return dir;
-	switch (dir) {
-	default:
-	case XFRM_POLICY_IN:
-		return FLOW_DIR_IN;
-	case XFRM_POLICY_OUT:
-		return FLOW_DIR_OUT;
-	case XFRM_POLICY_FWD:
-		return FLOW_DIR_FWD;
-	};
-}
 
 static int stale_bundle(struct dst_entry *dst);
 
@@ -739,33 +783,35 @@ int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
 	int nx = 0;
 	int err;
 	u32 genid;
-	u16 family = dst_orig->ops->family;
+	u16 family;
+	u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
+	u32 sk_sid = security_sk_sid(sk, fl, dir);
 restart:
 	genid = atomic_read(&flow_cache_genid);
 	policy = NULL;
 	if (sk && sk->sk_policy[1])
-		policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
+		policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, sk_sid);
 
 	if (!policy) {
 		/* To accelerate a bit...  */
 		if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT])
 			return 0;
 
-		policy = flow_cache_lookup(fl, family,
-					   policy_to_flow_dir(XFRM_POLICY_OUT),
-					   xfrm_policy_lookup);
+		policy = flow_cache_lookup(fl, sk_sid, dst_orig->ops->family,
+					   dir, xfrm_policy_lookup);
 	}
 
 	if (!policy)
 		return 0;
 
+	family = dst_orig->ops->family;
 	policy->curlft.use_time = (unsigned long)xtime.tv_sec;
 
 	switch (policy->action) {
 	case XFRM_POLICY_BLOCK:
 		/* Prohibit the flow */
-		xfrm_pol_put(policy);
-		return -EPERM;
+		err = -EPERM;
+		goto error;
 
 	case XFRM_POLICY_ALLOW:
 		if (policy->xfrm_nr == 0) {
@@ -781,8 +827,8 @@ restart:
 		 */
 		dst = xfrm_find_bundle(fl, policy, family);
 		if (IS_ERR(dst)) {
-			xfrm_pol_put(policy);
-			return PTR_ERR(dst);
+			err = PTR_ERR(dst);
+			goto error;
 		}
 
 		if (dst)
@@ -841,11 +887,11 @@ restart:
 			 * We can't enlist stable bundles either.
 			 */
 			write_unlock_bh(&policy->lock);
-
-			xfrm_pol_put(policy);
 			if (dst)
 				dst_free(dst);
-			goto restart;
+
+			err = -EHOSTUNREACH;
+			goto error;
 		}
 		dst->next = policy->bundles;
 		policy->bundles = dst;
@@ -897,16 +943,16 @@ xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
 	} else
 		start = -1;
 	for (; idx < sp->len; idx++) {
-		if (xfrm_state_ok(tmpl, sp->x[idx].xvec, family))
+		if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
 			return ++idx;
-		if (sp->x[idx].xvec->props.mode)
+		if (sp->xvec[idx]->props.mode)
 			break;
 	}
 	return start;
 }
 
-static int
-_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
+int
+xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
 {
 	struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 
@@ -917,11 +963,12 @@ _decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
 	xfrm_policy_put_afinfo(afinfo);
 	return 0;
 }
+EXPORT_SYMBOL(xfrm_decode_session);
 
 static inline int secpath_has_tunnel(struct sec_path *sp, int k)
 {
 	for (; k < sp->len; k++) {
-		if (sp->x[k].xvec->props.mode)
+		if (sp->xvec[k]->props.mode)
 			return 1;
 	}
 
@@ -933,35 +980,32 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 {
 	struct xfrm_policy *pol;
 	struct flowi fl;
+	u8 fl_dir = policy_to_flow_dir(dir);
+	u32 sk_sid;
 
-	if (_decode_session(skb, &fl, family) < 0)
+	if (xfrm_decode_session(skb, &fl, family) < 0)
 		return 0;
+	nf_nat_decode_session(skb, &fl, family);
+
+	sk_sid = security_sk_sid(sk, &fl, fl_dir);
 
 	/* First, check used SA against their selectors. */
 	if (skb->sp) {
 		int i;
 
 		for (i=skb->sp->len-1; i>=0; i--) {
-		  struct sec_decap_state *xvec = &(skb->sp->x[i]);
-			if (!xfrm_selector_match(&xvec->xvec->sel, &fl, family))
-				return 0;
-
-			/* If there is a post_input processor, try running it */
-			if (xvec->xvec->type->post_input &&
-			    (xvec->xvec->type->post_input)(xvec->xvec,
-							   &(xvec->decap),
-							   skb) != 0)
+			struct xfrm_state *x = skb->sp->xvec[i];
+			if (!xfrm_selector_match(&x->sel, &fl, family))
 				return 0;
 		}
 	}
 
 	pol = NULL;
 	if (sk && sk->sk_policy[dir])
-		pol = xfrm_sk_policy_lookup(sk, dir, &fl);
+		pol = xfrm_sk_policy_lookup(sk, dir, &fl, sk_sid);
 
 	if (!pol)
-		pol = flow_cache_lookup(&fl, family,
-					policy_to_flow_dir(dir),
+		pol = flow_cache_lookup(&fl, sk_sid, family, fl_dir,
 					xfrm_policy_lookup);
 
 	if (!pol)
@@ -1006,20 +1050,19 @@ int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
 {
 	struct flowi fl;
 
-	if (_decode_session(skb, &fl, family) < 0)
+	if (xfrm_decode_session(skb, &fl, family) < 0)
 		return 0;
 
 	return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
 }
 EXPORT_SYMBOL(__xfrm_route_forward);
 
-/* Optimize later using cookies and generation ids. */
-
 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
 {
-	if (!stale_bundle(dst))
-		return dst;
-
+	/* If it is marked obsolete, which is how we even get here,
+	 * then we have purged it from the policy bundle list and we
+	 * did that for a good reason.
+	 */
 	return NULL;
 }
 
@@ -1103,6 +1146,16 @@ int xfrm_flush_bundles(void)
 	return 0;
 }
 
+static int always_true(struct dst_entry *dst)
+{
+	return 1;
+}
+
+void xfrm_flush_all_bundles(void)
+{
+	xfrm_prune_bundles(always_true);
+}
+
 void xfrm_init_pmtu(struct dst_entry *dst)
 {
 	do {
@@ -1191,46 +1244,6 @@ int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family)
 
 EXPORT_SYMBOL(xfrm_bundle_ok);
 
-/* Well... that's _TASK_. We need to scan through transformation
- * list and figure out what mss tcp should generate in order to
- * final datagram fit to mtu. Mama mia... :-)
- *
- * Apparently, some easy way exists, but we used to choose the most
- * bizarre ones. :-) So, raising Kalashnikov... tra-ta-ta.
- *
- * Consider this function as something like dark humour. :-)
- */
-static int xfrm_get_mss(struct dst_entry *dst, u32 mtu)
-{
-	int res = mtu - dst->header_len;
-
-	for (;;) {
-		struct dst_entry *d = dst;
-		int m = res;
-
-		do {
-			struct xfrm_state *x = d->xfrm;
-			if (x) {
-				spin_lock_bh(&x->lock);
-				if (x->km.state == XFRM_STATE_VALID &&
-				    x->type && x->type->get_max_size)
-					m = x->type->get_max_size(d->xfrm, m);
-				else
-					m += x->props.header_len;
-				spin_unlock_bh(&x->lock);
-			}
-		} while ((d = d->child) != NULL);
-
-		if (m <= mtu)
-			break;
-		res -= (m - mtu);
-		if (res < 88)
-			return mtu;
-	}
-
-	return res + dst->header_len;
-}
-
 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
 {
 	int err = 0;
@@ -1238,7 +1251,7 @@ int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
 		return -EINVAL;
 	if (unlikely(afinfo->family >= NPROTO))
 		return -EAFNOSUPPORT;
-	write_lock(&xfrm_policy_afinfo_lock);
+	write_lock_bh(&xfrm_policy_afinfo_lock);
 	if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
 		err = -ENOBUFS;
 	else {
@@ -1251,13 +1264,11 @@ int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
 			dst_ops->negative_advice = xfrm_negative_advice;
 		if (likely(dst_ops->link_failure == NULL))
 			dst_ops->link_failure = xfrm_link_failure;
-		if (likely(dst_ops->get_mss == NULL))
-			dst_ops->get_mss = xfrm_get_mss;
 		if (likely(afinfo->garbage_collect == NULL))
 			afinfo->garbage_collect = __xfrm_garbage_collect;
 		xfrm_policy_afinfo[afinfo->family] = afinfo;
 	}
-	write_unlock(&xfrm_policy_afinfo_lock);
+	write_unlock_bh(&xfrm_policy_afinfo_lock);
 	return err;
 }
 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
@@ -1269,7 +1280,7 @@ int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
 		return -EINVAL;
 	if (unlikely(afinfo->family >= NPROTO))
 		return -EAFNOSUPPORT;
-	write_lock(&xfrm_policy_afinfo_lock);
+	write_lock_bh(&xfrm_policy_afinfo_lock);
 	if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
 		if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
 			err = -EINVAL;
@@ -1280,11 +1291,10 @@ int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
 			dst_ops->check = NULL;
 			dst_ops->negative_advice = NULL;
 			dst_ops->link_failure = NULL;
-			dst_ops->get_mss = NULL;
 			afinfo->garbage_collect = NULL;
 		}
 	}
-	write_unlock(&xfrm_policy_afinfo_lock);
+	write_unlock_bh(&xfrm_policy_afinfo_lock);
 	return err;
 }
 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);