4 files changed, 34 insertions, 7 deletions
diff --git a/net/dns_resolver/Kconfig b/net/dns_resolver/Kconfig
index 50d49f7e0472..0a1c2238b4bd 100644
--- a/net/dns_resolver/Kconfig
+++ b/net/dns_resolver/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Configuration for DNS Resolver
 #
diff --git a/net/dns_resolver/Makefile b/net/dns_resolver/Makefile
index d5c13c2eb36d..877532d662d0 100644
--- a/net/dns_resolver/Makefile
+++ b/net/dns_resolver/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Makefile for the Linux DNS Resolver.
 #
diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index a65d553e730d..6b201531b165 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -46,6 +46,15 @@ const struct cred *dns_resolver_cache;
 
 #define	DNS_ERRORNO_OPTION	"dnserror"
 
+static struct key_acl dns_keyring_acl = {
+	.usage	= REFCOUNT_INIT(1),
+	.nr_ace	= 2,
+	.aces = {
+		KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+		KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ | KEY_ACE_CLEAR),
+	}
+};
+
 /*
  * Preparse instantiation data for a dns_resolver key.
  *
@@ -314,6 +323,7 @@ static long dns_resolver_read(const struct key *key,
 
 struct key_type key_type_dns_resolver = {
 	.name		= "dns_resolver",
+	.flags		= KEY_TYPE_NET_DOMAIN,
 	.preparse	= dns_resolver_preparse,
 	.free_preparse	= dns_resolver_free_preparse,
 	.instantiate	= generic_key_instantiate,
@@ -342,8 +352,7 @@ static int __init init_dns_resolver(void)
 
 	keyring = keyring_alloc(".dns_resolver",
 				GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
-				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
-				KEY_USR_VIEW | KEY_USR_READ,
+				&dns_keyring_acl,
 				KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index 19aa32fc1802..236baf2bfa4c 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -40,20 +40,33 @@
 #include <linux/cred.h>
 #include <linux/dns_resolver.h>
 #include <linux/err.h>
+#include <net/net_namespace.h>
 
 #include <keys/dns_resolver-type.h>
 #include <keys/user-type.h>
 
 #include "internal.h"
 
+static struct key_acl dns_key_acl = {
+	.usage	= REFCOUNT_INIT(1),
+	.nr_ace	= 2,
+	.possessor_viewable = true,
+	.aces = {
+		KEY_POSSESSOR_ACE(KEY_ACE_VIEW | KEY_ACE_SEARCH | KEY_ACE_READ),
+		KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_INVAL),
+	}
+};
+
 /**
  * dns_query - Query the DNS
+ * @net: The network namespace to operate in.
  * @type: Query type (or NULL for straight host->IP lookup)
  * @name: Name to look up
  * @namelen: Length of name
  * @options: Request options (or NULL if no options)
  * @_result: Where to place the returned data (or NULL)
  * @_expiry: Where to store the result expiry time (or NULL)
+ * @invalidate: Always invalidate the key after use
  *
  * The data will be returned in the pointer at *result, if provided, and the
  * caller is responsible for freeing it.
@@ -68,8 +81,10 @@
  *
  * Returns the size of the result on success, -ve error code otherwise.
  */
-int dns_query(const char *type, const char *name, size_t namelen,
-	      const char *options, char **_result, time64_t *_expiry)
+int dns_query(struct net *net,
+	      const char *type, const char *name, size_t namelen,
+	      const char *options, char **_result, time64_t *_expiry,
+	      bool invalidate)
 {
 	struct key *rkey;
 	struct user_key_payload *upayload;
@@ -120,7 +135,8 @@ int dns_query(const char *type, const char *name, size_t namelen,
 	 * add_key() to preinstall malicious redirections
 	 */
 	saved_cred = override_creds(dns_resolver_cache);
-	rkey = request_key(&key_type_dns_resolver, desc, options);
+	rkey = request_key_net(&key_type_dns_resolver, desc, net, options,
+			       &dns_key_acl);
 	revert_creds(saved_cred);
 	kfree(desc);
 	if (IS_ERR(rkey)) {
@@ -130,8 +146,6 @@ int dns_query(const char *type, const char *name, size_t namelen,
 
 	down_read(&rkey->sem);
 	set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
-	rkey->perm |= KEY_USR_VIEW;
-
 	ret = key_validate(rkey);
 	if (ret < 0)
 		goto put;
@@ -157,6 +171,8 @@ int dns_query(const char *type, const char *name, size_t namelen,
 	ret = len;
 put:
 	up_read(&rkey->sem);
+	if (invalidate)
+		key_invalidate(rkey);
 	key_put(rkey);
 out:
 	kleave(" = %d", ret);