1 files changed, 148 insertions, 159 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7554803218a2..6332a0e06596 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -59,7 +59,6 @@
 #include <linux/rhashtable.h>
 #include <asm/cacheflush.h>
 #include <linux/hash.h>
-#include <linux/genetlink.h>
 #include <linux/net_namespace.h>
 #include <linux/nospec.h>
 #include <linux/btf_ids.h>
@@ -73,6 +72,7 @@
 #include <trace/events/netlink.h>
 
 #include "af_netlink.h"
+#include "genetlink.h"
 
 struct listeners {
 	struct rcu_head		rcu;
@@ -387,21 +387,11 @@ static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 	WARN_ON(skb->sk != NULL);
 	skb->sk = sk;
 	skb->destructor = netlink_skb_destructor;
-	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
 	sk_mem_charge(sk, skb->truesize);
 }
 
 static void netlink_sock_destruct(struct sock *sk)
 {
-	struct netlink_sock *nlk = nlk_sk(sk);
-
-	if (nlk->cb_running) {
-		if (nlk->cb.done)
-			nlk->cb.done(&nlk->cb);
-		module_put(nlk->cb.module);
-		kfree_skb(nlk->cb.skb);
-	}
-
 	skb_queue_purge(&sk->sk_receive_queue);
 
 	if (!sock_flag(sk, SOCK_DEAD)) {
@@ -414,14 +404,6 @@ static void netlink_sock_destruct(struct sock *sk)
 	WARN_ON(nlk_sk(sk)->groups);
 }
 
-static void netlink_sock_destruct_work(struct work_struct *work)
-{
-	struct netlink_sock *nlk = container_of(work, struct netlink_sock,
-						work);
-
-	sk_free(&nlk->sk);
-}
-
 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
  * SMP. Look, when several writers sleep and reader wakes them up, all but one
  * immediately hit write lock and grab all the cpus. Exclusive sleep solves
@@ -636,8 +618,7 @@ static struct proto netlink_proto = {
 };
 
 static int __netlink_create(struct net *net, struct socket *sock,
-			    struct mutex *dump_cb_mutex, int protocol,
-			    int kern)
+			    int protocol, int kern)
 {
 	struct sock *sk;
 	struct netlink_sock *nlk;
@@ -655,7 +636,6 @@ static int __netlink_create(struct net *net, struct socket *sock,
 	lockdep_set_class_and_name(&nlk->nl_cb_mutex,
 					   nlk_cb_mutex_keys + protocol,
 					   nlk_cb_mutex_key_strings[protocol]);
-	nlk->dump_cb_mutex = dump_cb_mutex;
 	init_waitqueue_head(&nlk->wait);
 
 	sk->sk_destruct = netlink_sock_destruct;
@@ -667,7 +647,6 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
 			  int kern)
 {
 	struct module *module = NULL;
-	struct mutex *cb_mutex;
 	struct netlink_sock *nlk;
 	int (*bind)(struct net *net, int group);
 	void (*unbind)(struct net *net, int group);
@@ -696,7 +675,6 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
 		module = nl_table[protocol].module;
 	else
 		err = -EPROTONOSUPPORT;
-	cb_mutex = nl_table[protocol].cb_mutex;
 	bind = nl_table[protocol].bind;
 	unbind = nl_table[protocol].unbind;
 	release = nl_table[protocol].release;
@@ -705,7 +683,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
 	if (err < 0)
 		goto out;
 
-	err = __netlink_create(net, sock, cb_mutex, protocol, kern);
+	err = __netlink_create(net, sock, protocol, kern);
 	if (err < 0)
 		goto out_module;
 
@@ -735,12 +713,6 @@ static void deferred_put_nlk_sk(struct rcu_head *head)
 	if (!refcount_dec_and_test(&sk->sk_refcnt))
 		return;
 
-	if (nlk->cb_running && nlk->cb.done) {
-		INIT_WORK(&nlk->work, netlink_sock_destruct_work);
-		schedule_work(&nlk->work);
-		return;
-	}
-
 	sk_free(sk);
 }
 
@@ -792,6 +764,15 @@ static int netlink_release(struct socket *sock)
 				NETLINK_URELEASE, &n);
 	}
 
+	/* Terminate any outstanding dump */
+	if (nlk->cb_running) {
+		if (nlk->cb.done)
+			nlk->cb.done(&nlk->cb);
+		module_put(nlk->cb.module);
+		kfree_skb(nlk->cb.skb);
+		WRITE_ONCE(nlk->cb_running, false);
+	}
+
 	module_put(nlk->module);
 
 	if (netlink_is_kernel(sk)) {
@@ -814,16 +795,6 @@ static int netlink_release(struct socket *sock)
 
 	sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
 
-	/* Because struct net might disappear soon, do not keep a pointer. */
-	if (!sk->sk_net_refcnt && sock_net(sk) != &init_net) {
-		__netns_tracker_free(sock_net(sk), &sk->ns_tracker, false);
-		/* Because of deferred_put_nlk_sk and use of work queue,
-		 * it is possible  netns will be freed before this socket.
-		 */
-		sock_net_set(sk, &init_net);
-		__netns_tracker_alloc(&init_net, &sk->ns_tracker,
-				      false, GFP_KERNEL);
-	}
 	call_rcu(&nlk->rcu, deferred_put_nlk_sk);
 	return 0;
 }
@@ -1184,11 +1155,16 @@ static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
 	return sock;
 }
 
-struct sock *netlink_getsockbyfilp(struct file *filp)
+struct sock *netlink_getsockbyfd(int fd)
 {
-	struct inode *inode = file_inode(filp);
+	CLASS(fd, f)(fd);
+	struct inode *inode;
 	struct sock *sock;
 
+	if (fd_empty(f))
+		return ERR_PTR(-EBADF);
+
+	inode = file_inode(fd_file(f));
 	if (!S_ISSOCK(inode->i_mode))
 		return ERR_PTR(-ENOTSOCK);
 
@@ -1235,41 +1211,48 @@ struct sk_buff *netlink_alloc_large_skb(unsigned int size, int broadcast)
 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
 		      long *timeo, struct sock *ssk)
 {
+	DECLARE_WAITQUEUE(wait, current);
 	struct netlink_sock *nlk;
+	unsigned int rmem;
 
 	nlk = nlk_sk(sk);
+	rmem = atomic_add_return(skb->truesize, &sk->sk_rmem_alloc);
 
-	if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
-	     test_bit(NETLINK_S_CONGESTED, &nlk->state))) {
-		DECLARE_WAITQUEUE(wait, current);
-		if (!*timeo) {
-			if (!ssk || netlink_is_kernel(ssk))
-				netlink_overrun(sk);
-			sock_put(sk);
-			kfree_skb(skb);
-			return -EAGAIN;
-		}
-
-		__set_current_state(TASK_INTERRUPTIBLE);
-		add_wait_queue(&nlk->wait, &wait);
+	if ((rmem == skb->truesize || rmem < READ_ONCE(sk->sk_rcvbuf)) &&
+	    !test_bit(NETLINK_S_CONGESTED, &nlk->state)) {
+		netlink_skb_set_owner_r(skb, sk);
+		return 0;
+	}
 
-		if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
-		     test_bit(NETLINK_S_CONGESTED, &nlk->state)) &&
-		    !sock_flag(sk, SOCK_DEAD))
-			*timeo = schedule_timeout(*timeo);
+	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
 
-		__set_current_state(TASK_RUNNING);
-		remove_wait_queue(&nlk->wait, &wait);
+	if (!*timeo) {
+		if (!ssk || netlink_is_kernel(ssk))
+			netlink_overrun(sk);
 		sock_put(sk);
+		kfree_skb(skb);
+		return -EAGAIN;
+	}
 
-		if (signal_pending(current)) {
-			kfree_skb(skb);
-			return sock_intr_errno(*timeo);
-		}
-		return 1;
+	__set_current_state(TASK_INTERRUPTIBLE);
+	add_wait_queue(&nlk->wait, &wait);
+	rmem = atomic_read(&sk->sk_rmem_alloc);
+
+	if (((rmem && rmem + skb->truesize > READ_ONCE(sk->sk_rcvbuf)) ||
+	     test_bit(NETLINK_S_CONGESTED, &nlk->state)) &&
+	    !sock_flag(sk, SOCK_DEAD))
+		*timeo = schedule_timeout(*timeo);
+
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&nlk->wait, &wait);
+	sock_put(sk);
+
+	if (signal_pending(current)) {
+		kfree_skb(skb);
+		return sock_intr_errno(*timeo);
 	}
-	netlink_skb_set_owner_r(skb, sk);
-	return 0;
+
+	return 1;
 }
 
 static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
@@ -1301,6 +1284,7 @@ static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
 {
 	int delta;
 
+	skb_assert_len(skb);
 	WARN_ON(skb->sk != NULL);
 	delta = skb->end - skb->tail;
 	if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize)
@@ -1329,6 +1313,7 @@ static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
 	ret = -ECONNREFUSED;
 	if (nlk->netlink_rcv != NULL) {
 		ret = skb->len;
+		atomic_add(skb->truesize, &sk->sk_rmem_alloc);
 		netlink_skb_set_owner_r(skb, sk);
 		NETLINK_CB(skb).sk = ssk;
 		netlink_deliver_tap_kernel(sk, ssk, skb);
@@ -1405,13 +1390,19 @@ EXPORT_SYMBOL_GPL(netlink_strict_get_check);
 static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
 {
 	struct netlink_sock *nlk = nlk_sk(sk);
+	unsigned int rmem, rcvbuf;
+
+	rmem = atomic_add_return(skb->truesize, &sk->sk_rmem_alloc);
+	rcvbuf = READ_ONCE(sk->sk_rcvbuf);
 
-	if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
+	if ((rmem == skb->truesize || rmem <= rcvbuf) &&
 	    !test_bit(NETLINK_S_CONGESTED, &nlk->state)) {
 		netlink_skb_set_owner_r(skb, sk);
 		__netlink_sendskb(sk, skb);
-		return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
+		return rmem > (rcvbuf >> 1);
 	}
+
+	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
 	return -1;
 }
 
@@ -2016,7 +2007,6 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
 	struct sock *sk;
 	struct netlink_sock *nlk;
 	struct listeners *listeners = NULL;
-	struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
 	unsigned int groups;
 
 	BUG_ON(!nl_table);
@@ -2027,7 +2017,7 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
 	if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
 		return NULL;
 
-	if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0)
+	if (__netlink_create(net, sock, unit, 1) < 0)
 		goto out_sock_release_nosk;
 
 	sk = sock->sk;
@@ -2055,7 +2045,6 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
 	if (!nl_table[unit].registered) {
 		nl_table[unit].groups = groups;
 		rcu_assign_pointer(nl_table[unit].listeners, listeners);
-		nl_table[unit].cb_mutex = cb_mutex;
 		nl_table[unit].module = module;
 		if (cfg) {
 			nl_table[unit].bind = cfg->bind;
@@ -2142,8 +2131,9 @@ void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
 {
 	struct sock *sk;
 	struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
+	struct hlist_node *tmp;
 
-	sk_for_each_bound(sk, &tbl->mc_list)
+	sk_for_each_bound_safe(sk, tmp, &tbl->mc_list)
 		netlink_update_socket_mc(nlk_sk(sk), group, 0);
 }
 
@@ -2165,6 +2155,70 @@ __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int fla
 }
 EXPORT_SYMBOL(__nlmsg_put);
 
+static size_t
+netlink_ack_tlv_len(struct netlink_sock *nlk, int err,
+		    const struct netlink_ext_ack *extack)
+{
+	size_t tlvlen;
+
+	if (!extack || !test_bit(NETLINK_F_EXT_ACK, &nlk->flags))
+		return 0;
+
+	tlvlen = 0;
+	if (extack->_msg)
+		tlvlen += nla_total_size(strlen(extack->_msg) + 1);
+	if (extack->cookie_len)
+		tlvlen += nla_total_size(extack->cookie_len);
+
+	/* Following attributes are only reported as error (not warning) */
+	if (!err)
+		return tlvlen;
+
+	if (extack->bad_attr)
+		tlvlen += nla_total_size(sizeof(u32));
+	if (extack->policy)
+		tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy);
+	if (extack->miss_type)
+		tlvlen += nla_total_size(sizeof(u32));
+	if (extack->miss_nest)
+		tlvlen += nla_total_size(sizeof(u32));
+
+	return tlvlen;
+}
+
+static bool nlmsg_check_in_payload(const struct nlmsghdr *nlh, const void *addr)
+{
+	return !WARN_ON(addr < nlmsg_data(nlh) ||
+			addr - (const void *) nlh >= nlh->nlmsg_len);
+}
+
+static void
+netlink_ack_tlv_fill(struct sk_buff *skb, const struct nlmsghdr *nlh, int err,
+		     const struct netlink_ext_ack *extack)
+{
+	if (extack->_msg)
+		WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg));
+	if (extack->cookie_len)
+		WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
+				extack->cookie_len, extack->cookie));
+
+	if (!err)
+		return;
+
+	if (extack->bad_attr && nlmsg_check_in_payload(nlh, extack->bad_attr))
+		WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
+				    (u8 *)extack->bad_attr - (const u8 *)nlh));
+	if (extack->policy)
+		netlink_policy_dump_write_attr(skb, extack->policy,
+					       NLMSGERR_ATTR_POLICY);
+	if (extack->miss_type)
+		WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_TYPE,
+				    extack->miss_type));
+	if (extack->miss_nest && nlmsg_check_in_payload(nlh, extack->miss_nest))
+		WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_NEST,
+				    (u8 *)extack->miss_nest - (const u8 *)nlh));
+}
+
 /*
  * It looks a bit ugly.
  * It would be better to create kernel thread.
@@ -2175,6 +2229,7 @@ static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb,
 			     struct netlink_ext_ack *extack)
 {
 	struct nlmsghdr *nlh;
+	size_t extack_len;
 
 	nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(nlk->dump_done_errno),
 			       NLM_F_MULTI | cb->answer_flags);
@@ -2184,10 +2239,14 @@ static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb,
 	nl_dump_check_consistent(cb, nlh);
 	memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno));
 
-	if (extack->_msg && test_bit(NETLINK_F_EXT_ACK, &nlk->flags)) {
+	extack_len = netlink_ack_tlv_len(nlk, nlk->dump_done_errno, extack);
+	if (extack_len) {
 		nlh->nlmsg_flags |= NLM_F_ACK_TLVS;
-		if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg))
+		if (skb_tailroom(skb) >= extack_len) {
+			netlink_ack_tlv_fill(skb, cb->nlh,
+					     nlk->dump_done_errno, extack);
 			nlmsg_end(skb, nlh);
+		}
 	}
 
 	return 0;
@@ -2199,6 +2258,7 @@ static int netlink_dump(struct sock *sk, bool lock_taken)
 	struct netlink_ext_ack extack = {};
 	struct netlink_callback *cb;
 	struct sk_buff *skb = NULL;
+	unsigned int rmem, rcvbuf;
 	size_t max_recvmsg_len;
 	struct module *module;
 	int err = -ENOBUFS;
@@ -2212,11 +2272,8 @@ static int netlink_dump(struct sock *sk, bool lock_taken)
 		goto errout_skb;
 	}
 
-	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
-		goto errout_skb;
-
 	/* NLMSG_GOODSIZE is small to avoid high order allocations being
-	 * required, but it makes sense to _attempt_ a 16K bytes allocation
+	 * required, but it makes sense to _attempt_ a 32KiB allocation
 	 * to reduce number of system calls on dump operations, if user
 	 * ever provided a big enough buffer.
 	 */
@@ -2237,8 +2294,15 @@ static int netlink_dump(struct sock *sk, bool lock_taken)
 	if (!skb)
 		goto errout_skb;
 
+	rcvbuf = READ_ONCE(sk->sk_rcvbuf);
+	rmem = atomic_add_return(skb->truesize, &sk->sk_rmem_alloc);
+	if (rmem != skb->truesize && rmem >= rcvbuf) {
+		atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
+		goto errout_skb;
+	}
+
 	/* Trim skb to allocated size. User is expected to provide buffer as
-	 * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at
+	 * large as max(min_dump_alloc, 32KiB (max_recvmsg_len capped at
 	 * netlink_recvmsg())). dump will pack as many smaller messages as
 	 * could fit within the allocated skb. skb is typically allocated
 	 * with larger space than required (could be as much as near 2x the
@@ -2258,17 +2322,9 @@ static int netlink_dump(struct sock *sk, bool lock_taken)
 	netlink_skb_set_owner_r(skb, sk);
 
 	if (nlk->dump_done_errno > 0) {
-		struct mutex *extra_mutex = nlk->dump_cb_mutex;
-
 		cb->extack = &extack;
 
-		if (cb->flags & RTNL_FLAG_DUMP_UNLOCKED)
-			extra_mutex = NULL;
-		if (extra_mutex)
-			mutex_lock(extra_mutex);
 		nlk->dump_done_errno = cb->dump(skb, cb);
-		if (extra_mutex)
-			mutex_unlock(extra_mutex);
 
 		/* EMSGSIZE plus something already in the skb means
 		 * that there's more to dump but current skb has filled up.
@@ -2406,69 +2462,6 @@ error_free:
 }
 EXPORT_SYMBOL(__netlink_dump_start);
 
-static size_t
-netlink_ack_tlv_len(struct netlink_sock *nlk, int err,
-		    const struct netlink_ext_ack *extack)
-{
-	size_t tlvlen;
-
-	if (!extack || !test_bit(NETLINK_F_EXT_ACK, &nlk->flags))
-		return 0;
-
-	tlvlen = 0;
-	if (extack->_msg)
-		tlvlen += nla_total_size(strlen(extack->_msg) + 1);
-	if (extack->cookie_len)
-		tlvlen += nla_total_size(extack->cookie_len);
-
-	/* Following attributes are only reported as error (not warning) */
-	if (!err)
-		return tlvlen;
-
-	if (extack->bad_attr)
-		tlvlen += nla_total_size(sizeof(u32));
-	if (extack->policy)
-		tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy);
-	if (extack->miss_type)
-		tlvlen += nla_total_size(sizeof(u32));
-	if (extack->miss_nest)
-		tlvlen += nla_total_size(sizeof(u32));
-
-	return tlvlen;
-}
-
-static void
-netlink_ack_tlv_fill(struct sk_buff *in_skb, struct sk_buff *skb,
-		     struct nlmsghdr *nlh, int err,
-		     const struct netlink_ext_ack *extack)
-{
-	if (extack->_msg)
-		WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg));
-	if (extack->cookie_len)
-		WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
-				extack->cookie_len, extack->cookie));
-
-	if (!err)
-		return;
-
-	if (extack->bad_attr &&
-	    !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
-		     (u8 *)extack->bad_attr >= in_skb->data + in_skb->len))
-		WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
-				    (u8 *)extack->bad_attr - (u8 *)nlh));
-	if (extack->policy)
-		netlink_policy_dump_write_attr(skb, extack->policy,
-					       NLMSGERR_ATTR_POLICY);
-	if (extack->miss_type)
-		WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_TYPE,
-				    extack->miss_type));
-	if (extack->miss_nest &&
-	    !WARN_ON((u8 *)extack->miss_nest < in_skb->data ||
-		     (u8 *)extack->miss_nest > in_skb->data + in_skb->len))
-		WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_NEST,
-				    (u8 *)extack->miss_nest - (u8 *)nlh));
-}
-
 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
 		 const struct netlink_ext_ack *extack)
 {
@@ -2514,7 +2507,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
 	}
 
 	if (tlvlen)
-		netlink_ack_tlv_fill(in_skb, skb, nlh, err, extack);
+		netlink_ack_tlv_fill(skb, nlh, err, extack);
 
 	nlmsg_end(skb, rep);
 
@@ -2943,12 +2936,8 @@ static int __init netlink_proto_init(void)
 
 	for (i = 0; i < MAX_LINKS; i++) {
 		if (rhashtable_init(&nl_table[i].hash,
-				    &netlink_rhashtable_params) < 0) {
-			while (--i > 0)
-				rhashtable_destroy(&nl_table[i].hash);
-			kfree(nl_table);
+				    &netlink_rhashtable_params) < 0)
 			goto panic;
-		}
 	}
 
 	netlink_add_usersock_entry();