1 files changed, 187 insertions, 38 deletions

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 5b6d7f6956b..9ebf9e20de5 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -15,21 +15,34 @@
  */
 
 #include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/kobject.h>
+#include <linux/export.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/user_namespace.h>
 #include <linux/socket.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
-#include <linux/string.h>
-#include <linux/kobject.h>
 #include <net/sock.h>
+#include <net/net_namespace.h>
 
 
 u64 uevent_seqnum;
+#ifdef CONFIG_UEVENT_HELPER
 char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
-static DEFINE_SPINLOCK(sequence_lock);
-#if defined(CONFIG_NET)
-static struct sock *uevent_sock;
+#endif
+#ifdef CONFIG_NET
+struct uevent_sock {
+	struct list_head list;
+	struct sock *sk;
+};
+static LIST_HEAD(uevent_sock_list);
 #endif
 
+/* This lock protects uevent_seqnum and uevent_sock_list */
+static DEFINE_MUTEX(uevent_sock_mutex);
+
 /* the strings here must match the enum in include/linux/kobject.h */
 static const char *kobject_actions[] = {
 	[KOBJ_ADD] =		"add",
@@ -74,6 +87,71 @@ out:
 	return ret;
 }
 
+#ifdef CONFIG_NET
+static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data)
+{
+	struct kobject *kobj = data, *ksobj;
+	const struct kobj_ns_type_operations *ops;
+
+	ops = kobj_ns_ops(kobj);
+	if (!ops && kobj->kset) {
+		ksobj = &kobj->kset->kobj;
+		if (ksobj->parent != NULL)
+			ops = kobj_ns_ops(ksobj->parent);
+	}
+
+	if (ops && ops->netlink_ns && kobj->ktype->namespace) {
+		const void *sock_ns, *ns;
+		ns = kobj->ktype->namespace(kobj);
+		sock_ns = ops->netlink_ns(dsk);
+		return sock_ns != ns;
+	}
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_UEVENT_HELPER
+static int kobj_usermode_filter(struct kobject *kobj)
+{
+	const struct kobj_ns_type_operations *ops;
+
+	ops = kobj_ns_ops(kobj);
+	if (ops) {
+		const void *init_ns, *ns;
+		ns = kobj->ktype->namespace(kobj);
+		init_ns = ops->initial_ns();
+		return ns != init_ns;
+	}
+
+	return 0;
+}
+
+static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem)
+{
+	int len;
+
+	len = strlcpy(&env->buf[env->buflen], subsystem,
+		      sizeof(env->buf) - env->buflen);
+	if (len >= (sizeof(env->buf) - env->buflen)) {
+		WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n");
+		return -ENOMEM;
+	}
+
+	env->argv[0] = uevent_helper;
+	env->argv[1] = &env->buf[env->buflen];
+	env->argv[2] = NULL;
+
+	env->buflen += len + 1;
+	return 0;
+}
+
+static void cleanup_uevent_env(struct subprocess_info *info)
+{
+	kfree(info->data);
+}
+#endif
+
 /**
  * kobject_uevent_env - send an uevent with environmental data
  *
@@ -81,7 +159,7 @@ out:
  * @kobj: struct kobject that the action is happening to
  * @envp_ext: pointer to environmental data
  *
- * Returns 0 if kobject_uevent() is completed with success or the
+ * Returns 0 if kobject_uevent_env() is completed with success or the
  * corresponding error when it fails.
  */
 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
@@ -93,13 +171,15 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	const char *subsystem;
 	struct kobject *top_kobj;
 	struct kset *kset;
-	struct kset_uevent_ops *uevent_ops;
-	u64 seq;
+	const struct kset_uevent_ops *uevent_ops;
 	int i = 0;
 	int retval = 0;
+#ifdef CONFIG_NET
+	struct uevent_sock *ue_sk;
+#endif
 
 	pr_debug("kobject: '%s' (%p): %s\n",
-		 kobject_name(kobj), kobj, __FUNCTION__);
+		 kobject_name(kobj), kobj, __func__);
 
 	/* search the kset we belong to */
 	top_kobj = kobj;
@@ -109,19 +189,26 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	if (!top_kobj->kset) {
 		pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
 			 "without kset!\n", kobject_name(kobj), kobj,
-			 __FUNCTION__);
+			 __func__);
 		return -EINVAL;
 	}
 
 	kset = top_kobj->kset;
 	uevent_ops = kset->uevent_ops;
 
+	/* skip the event, if uevent_suppress is set*/
+	if (kobj->uevent_suppress) {
+		pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
+				 "caused the event to drop!\n",
+				 kobject_name(kobj), kobj, __func__);
+		return 0;
+	}
 	/* skip the event, if the filter returns zero. */
 	if (uevent_ops && uevent_ops->filter)
 		if (!uevent_ops->filter(kset, kobj)) {
 			pr_debug("kobject: '%s' (%p): %s: filter function "
 				 "caused the event to drop!\n",
-				 kobject_name(kobj), kobj, __FUNCTION__);
+				 kobject_name(kobj), kobj, __func__);
 			return 0;
 		}
 
@@ -133,7 +220,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	if (!subsystem) {
 		pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
 			 "event to drop!\n", kobject_name(kobj), kobj,
-			 __FUNCTION__);
+			 __func__);
 		return 0;
 	}
 
@@ -163,7 +250,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	/* keys passed in from the caller */
 	if (envp_ext) {
 		for (i = 0; envp_ext[i]; i++) {
-			retval = add_uevent_var(env, envp_ext[i]);
+			retval = add_uevent_var(env, "%s", envp_ext[i]);
 			if (retval)
 				goto exit;
 		}
@@ -175,7 +262,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 		if (retval) {
 			pr_debug("kobject: '%s' (%p): %s: uevent() returned "
 				 "%d\n", kobject_name(kobj), kobj,
-				 __FUNCTION__, retval);
+				 __func__, retval);
 			goto exit;
 		}
 	}
@@ -191,20 +278,24 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	else if (action == KOBJ_REMOVE)
 		kobj->state_remove_uevent_sent = 1;
 
+	mutex_lock(&uevent_sock_mutex);
 	/* we will send an event, so request a new sequence number */
-	spin_lock(&sequence_lock);
-	seq = ++uevent_seqnum;
-	spin_unlock(&sequence_lock);
-	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
-	if (retval)
+	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
+	if (retval) {
+		mutex_unlock(&uevent_sock_mutex);
 		goto exit;
+	}
 
 #if defined(CONFIG_NET)
 	/* send netlink message */
-	if (uevent_sock) {
+	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
+		struct sock *uevent_sock = ue_sk->sk;
 		struct sk_buff *skb;
 		size_t len;
 
+		if (!netlink_has_listeners(uevent_sock, 1))
+			continue;
+
 		/* allocate message with the maximum possible size */
 		len = strlen(action_string) + strlen(devpath) + 2;
 		skb = alloc_skb(len + env->buflen, GFP_KERNEL);
@@ -223,18 +314,24 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 			}
 
 			NETLINK_CB(skb).dst_group = 1;
-			netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);
-		}
+			retval = netlink_broadcast_filtered(uevent_sock, skb,
+							    0, 1, GFP_KERNEL,
+							    kobj_bcast_filter,
+							    kobj);
+			/* ENOBUFS should be handled in userspace */
+			if (retval == -ENOBUFS || retval == -ESRCH)
+				retval = 0;
+		} else
+			retval = -ENOMEM;
 	}
 #endif
+	mutex_unlock(&uevent_sock_mutex);
 
+#ifdef CONFIG_UEVENT_HELPER
 	/* call uevent_helper, usually only enabled during early boot */
-	if (uevent_helper[0]) {
-		char *argv [3];
+	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
+		struct subprocess_info *info;
 
-		argv [0] = uevent_helper;
-		argv [1] = (char *)subsystem;
-		argv [2] = NULL;
 		retval = add_uevent_var(env, "HOME=/");
 		if (retval)
 			goto exit;
@@ -242,9 +339,20 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 					"PATH=/sbin:/bin:/usr/sbin:/usr/bin");
 		if (retval)
 			goto exit;
+		retval = init_uevent_argv(env, subsystem);
+		if (retval)
+			goto exit;
 
-		call_usermodehelper(argv[0], argv, env->envp, UMH_WAIT_EXEC);
+		retval = -ENOMEM;
+		info = call_usermodehelper_setup(env->argv[0], env->argv,
+						 env->envp, GFP_KERNEL,
+						 NULL, cleanup_uevent_env, env);
+		if (info) {
+			retval = call_usermodehelper_exec(info, UMH_NO_WAIT);
+			env = NULL;	/* freed by cleanup_uevent_env */
+		}
 	}
+#endif
 
 exit:
 	kfree(devpath);
@@ -254,7 +362,7 @@ exit:
 EXPORT_SYMBOL_GPL(kobject_uevent_env);
 
 /**
- * kobject_uevent - notify userspace by ending an uevent
+ * kobject_uevent - notify userspace by sending an uevent
  *
  * @action: action that is happening
  * @kobj: struct kobject that the action is happening to
@@ -282,8 +390,7 @@ int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 	int len;
 
 	if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
-		printk(KERN_ERR "add_uevent_var: too many keys\n");
-		WARN_ON(1);
+		WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
 		return -ENOMEM;
 	}
 
@@ -294,8 +401,7 @@ int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 	va_end(args);
 
 	if (len >= (sizeof(env->buf) - env->buflen)) {
-		printk(KERN_ERR "add_uevent_var: buffer size too small\n");
-		WARN_ON(1);
+		WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
 		return -ENOMEM;
 	}
 
@@ -306,18 +412,61 @@ int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 EXPORT_SYMBOL_GPL(add_uevent_var);
 
 #if defined(CONFIG_NET)
-static int __init kobject_uevent_init(void)
+static int uevent_net_init(struct net *net)
 {
-	uevent_sock = netlink_kernel_create(&init_net, NETLINK_KOBJECT_UEVENT,
-					    1, NULL, NULL, THIS_MODULE);
-	if (!uevent_sock) {
+	struct uevent_sock *ue_sk;
+	struct netlink_kernel_cfg cfg = {
+		.groups	= 1,
+		.flags	= NL_CFG_F_NONROOT_RECV,
+	};
+
+	ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
+	if (!ue_sk)
+		return -ENOMEM;
+
+	ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
+	if (!ue_sk->sk) {
 		printk(KERN_ERR
 		       "kobject_uevent: unable to create netlink socket!\n");
+		kfree(ue_sk);
 		return -ENODEV;
 	}
-
+	mutex_lock(&uevent_sock_mutex);
+	list_add_tail(&ue_sk->list, &uevent_sock_list);
+	mutex_unlock(&uevent_sock_mutex);
 	return 0;
 }
 
+static void uevent_net_exit(struct net *net)
+{
+	struct uevent_sock *ue_sk;
+
+	mutex_lock(&uevent_sock_mutex);
+	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
+		if (sock_net(ue_sk->sk) == net)
+			goto found;
+	}
+	mutex_unlock(&uevent_sock_mutex);
+	return;
+
+found:
+	list_del(&ue_sk->list);
+	mutex_unlock(&uevent_sock_mutex);
+
+	netlink_kernel_release(ue_sk->sk);
+	kfree(ue_sk);
+}
+
+static struct pernet_operations uevent_net_ops = {
+	.init	= uevent_net_init,
+	.exit	= uevent_net_exit,
+};
+
+static int __init kobject_uevent_init(void)
+{
+	return register_pernet_subsys(&uevent_net_ops);
+}
+
+
 postcore_initcall(kobject_uevent_init);
 #endif