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-rw-r--r--lib/kobject_uevent.c178
-rw-r--r--lib/rhashtable.c51
2 files changed, 172 insertions, 57 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 15ea216a67ce6..63d0816ab23b0 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -22,6 +22,7 @@
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
+#include <linux/uidgid.h>
#include <linux/uuid.h>
#include <linux/ctype.h>
#include <net/sock.h>
@@ -231,30 +232,6 @@ out:
return r;
}
-#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)
{
@@ -296,15 +273,44 @@ static void cleanup_uevent_env(struct subprocess_info *info)
}
#endif
-static int kobject_uevent_net_broadcast(struct kobject *kobj,
- struct kobj_uevent_env *env,
+#ifdef CONFIG_NET
+static struct sk_buff *alloc_uevent_skb(struct kobj_uevent_env *env,
const char *action_string,
const char *devpath)
{
- int retval = 0;
-#if defined(CONFIG_NET)
+ struct netlink_skb_parms *parms;
+ struct sk_buff *skb = NULL;
+ char *scratch;
+ size_t len;
+
+ /* allocate message with maximum possible size */
+ len = strlen(action_string) + strlen(devpath) + 2;
+ skb = alloc_skb(len + env->buflen, GFP_KERNEL);
+ if (!skb)
+ return NULL;
+
+ /* add header */
+ scratch = skb_put(skb, len);
+ sprintf(scratch, "%s@%s", action_string, devpath);
+
+ skb_put_data(skb, env->buf, env->buflen);
+
+ parms = &NETLINK_CB(skb);
+ parms->creds.uid = GLOBAL_ROOT_UID;
+ parms->creds.gid = GLOBAL_ROOT_GID;
+ parms->dst_group = 1;
+ parms->portid = 0;
+
+ return skb;
+}
+
+static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env,
+ const char *action_string,
+ const char *devpath)
+{
struct sk_buff *skb = NULL;
struct uevent_sock *ue_sk;
+ int retval = 0;
/* send netlink message */
list_for_each_entry(ue_sk, &uevent_sock_list, list) {
@@ -314,37 +320,99 @@ static int kobject_uevent_net_broadcast(struct kobject *kobj,
continue;
if (!skb) {
- /* allocate message with the maximum possible size */
- size_t len = strlen(action_string) + strlen(devpath) + 2;
- char *scratch;
-
retval = -ENOMEM;
- skb = alloc_skb(len + env->buflen, GFP_KERNEL);
+ skb = alloc_uevent_skb(env, action_string, devpath);
if (!skb)
continue;
-
- /* add header */
- scratch = skb_put(skb, len);
- sprintf(scratch, "%s@%s", action_string, devpath);
-
- skb_put_data(skb, env->buf, env->buflen);
-
- NETLINK_CB(skb).dst_group = 1;
}
- retval = netlink_broadcast_filtered(uevent_sock, skb_get(skb),
- 0, 1, GFP_KERNEL,
- kobj_bcast_filter,
- kobj);
+ retval = netlink_broadcast(uevent_sock, skb_get(skb), 0, 1,
+ GFP_KERNEL);
/* ENOBUFS should be handled in userspace */
if (retval == -ENOBUFS || retval == -ESRCH)
retval = 0;
}
consume_skb(skb);
-#endif
+
return retval;
}
+static int uevent_net_broadcast_tagged(struct sock *usk,
+ struct kobj_uevent_env *env,
+ const char *action_string,
+ const char *devpath)
+{
+ struct user_namespace *owning_user_ns = sock_net(usk)->user_ns;
+ struct sk_buff *skb = NULL;
+ int ret = 0;
+
+ skb = alloc_uevent_skb(env, action_string, devpath);
+ if (!skb)
+ return -ENOMEM;
+
+ /* fix credentials */
+ if (owning_user_ns != &init_user_ns) {
+ struct netlink_skb_parms *parms = &NETLINK_CB(skb);
+ kuid_t root_uid;
+ kgid_t root_gid;
+
+ /* fix uid */
+ root_uid = make_kuid(owning_user_ns, 0);
+ if (uid_valid(root_uid))
+ parms->creds.uid = root_uid;
+
+ /* fix gid */
+ root_gid = make_kgid(owning_user_ns, 0);
+ if (gid_valid(root_gid))
+ parms->creds.gid = root_gid;
+ }
+
+ ret = netlink_broadcast(usk, skb, 0, 1, GFP_KERNEL);
+ /* ENOBUFS should be handled in userspace */
+ if (ret == -ENOBUFS || ret == -ESRCH)
+ ret = 0;
+
+ return ret;
+}
+#endif
+
+static int kobject_uevent_net_broadcast(struct kobject *kobj,
+ struct kobj_uevent_env *env,
+ const char *action_string,
+ const char *devpath)
+{
+ int ret = 0;
+
+#ifdef CONFIG_NET
+ const struct kobj_ns_type_operations *ops;
+ const struct net *net = NULL;
+
+ ops = kobj_ns_ops(kobj);
+ if (!ops && kobj->kset) {
+ struct kobject *ksobj = &kobj->kset->kobj;
+ if (ksobj->parent != NULL)
+ ops = kobj_ns_ops(ksobj->parent);
+ }
+
+ /* kobjects currently only carry network namespace tags and they
+ * are the only tag relevant here since we want to decide which
+ * network namespaces to broadcast the uevent into.
+ */
+ if (ops && ops->netlink_ns && kobj->ktype->namespace)
+ if (ops->type == KOBJ_NS_TYPE_NET)
+ net = kobj->ktype->namespace(kobj);
+
+ if (!net)
+ ret = uevent_net_broadcast_untagged(env, action_string,
+ devpath);
+ else
+ ret = uevent_net_broadcast_tagged(net->uevent_sock->sk, env,
+ action_string, devpath);
+#endif
+
+ return ret;
+}
+
static void zap_modalias_env(struct kobj_uevent_env *env)
{
static const char modalias_prefix[] = "MODALIAS=";
@@ -703,9 +771,13 @@ static int uevent_net_init(struct net *net)
net->uevent_sock = ue_sk;
- mutex_lock(&uevent_sock_mutex);
- list_add_tail(&ue_sk->list, &uevent_sock_list);
- mutex_unlock(&uevent_sock_mutex);
+ /* Restrict uevents to initial user namespace. */
+ if (sock_net(ue_sk->sk)->user_ns == &init_user_ns) {
+ mutex_lock(&uevent_sock_mutex);
+ list_add_tail(&ue_sk->list, &uevent_sock_list);
+ mutex_unlock(&uevent_sock_mutex);
+ }
+
return 0;
}
@@ -713,9 +785,11 @@ static void uevent_net_exit(struct net *net)
{
struct uevent_sock *ue_sk = net->uevent_sock;
- mutex_lock(&uevent_sock_mutex);
- list_del(&ue_sk->list);
- mutex_unlock(&uevent_sock_mutex);
+ if (sock_net(ue_sk->sk)->user_ns == &init_user_ns) {
+ mutex_lock(&uevent_sock_mutex);
+ list_del(&ue_sk->list);
+ mutex_unlock(&uevent_sock_mutex);
+ }
netlink_kernel_release(ue_sk->sk);
kfree(ue_sk);
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 2b2b79974b614..9427b5766134c 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -668,8 +668,9 @@ EXPORT_SYMBOL_GPL(rhashtable_insert_slow);
* For a completely stable walk you should construct your own data
* structure outside the hash table.
*
- * This function may sleep so you must not call it from interrupt
- * context or with spin locks held.
+ * This function may be called from any process context, including
+ * non-preemptable context, but cannot be called from softirq or
+ * hardirq context.
*
* You must call rhashtable_walk_exit after this function returns.
*/
@@ -726,6 +727,7 @@ int rhashtable_walk_start_check(struct rhashtable_iter *iter)
__acquires(RCU)
{
struct rhashtable *ht = iter->ht;
+ bool rhlist = ht->rhlist;
rcu_read_lock();
@@ -734,11 +736,52 @@ int rhashtable_walk_start_check(struct rhashtable_iter *iter)
list_del(&iter->walker.list);
spin_unlock(&ht->lock);
- if (!iter->walker.tbl && !iter->end_of_table) {
+ if (iter->end_of_table)
+ return 0;
+ if (!iter->walker.tbl) {
iter->walker.tbl = rht_dereference_rcu(ht->tbl, ht);
+ iter->slot = 0;
+ iter->skip = 0;
return -EAGAIN;
}
+ if (iter->p && !rhlist) {
+ /*
+ * We need to validate that 'p' is still in the table, and
+ * if so, update 'skip'
+ */
+ struct rhash_head *p;
+ int skip = 0;
+ rht_for_each_rcu(p, iter->walker.tbl, iter->slot) {
+ skip++;
+ if (p == iter->p) {
+ iter->skip = skip;
+ goto found;
+ }
+ }
+ iter->p = NULL;
+ } else if (iter->p && rhlist) {
+ /* Need to validate that 'list' is still in the table, and
+ * if so, update 'skip' and 'p'.
+ */
+ struct rhash_head *p;
+ struct rhlist_head *list;
+ int skip = 0;
+ rht_for_each_rcu(p, iter->walker.tbl, iter->slot) {
+ for (list = container_of(p, struct rhlist_head, rhead);
+ list;
+ list = rcu_dereference(list->next)) {
+ skip++;
+ if (list == iter->list) {
+ iter->p = p;
+ skip = skip;
+ goto found;
+ }
+ }
+ }
+ iter->p = NULL;
+ }
+found:
return 0;
}
EXPORT_SYMBOL_GPL(rhashtable_walk_start_check);
@@ -914,8 +957,6 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter)
iter->walker.tbl = NULL;
spin_unlock(&ht->lock);
- iter->p = NULL;
-
out:
rcu_read_unlock();
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-24 11:35:19 +0000