aboutsummaryrefslogtreecommitdiff
path: root/lib/kobject_uevent.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/kobject_uevent.c')
-rw-r--r--lib/kobject_uevent.c196
1 files changed, 166 insertions, 30 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 920a3ca6e25..9ebf9e20de5 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -17,21 +17,32 @@
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/kobject.h>
-#include <linux/module.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 <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",
@@ -76,6 +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
*
@@ -83,7 +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,
@@ -95,10 +171,12 @@ 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, __func__);
@@ -200,20 +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);
@@ -232,23 +314,24 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
}
NETLINK_CB(skb).dst_group = 1;
- retval = 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)
+ 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;
@@ -256,10 +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;
- retval = 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);
@@ -269,7 +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
@@ -319,18 +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;
}
- netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV);
+ 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
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 12:09:38 +0000