Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 414 insertions, 0 deletions

diff --git a/drivers/net/wireguard/send.c b/drivers/net/wireguard/send.c
new file mode 100644
index 000000000..67d01478e
--- /dev/null
+++ b/drivers/net/wireguard/send.c
@@ -0,0 +1,414 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include "queueing.h"
+#include "timers.h"
+#include "device.h"
+#include "peer.h"
+#include "socket.h"
+#include "messages.h"
+#include "cookie.h"
+
+#include <linux/uio.h>
+#include <linux/inetdevice.h>
+#include <linux/socket.h>
+#include <net/ip_tunnels.h>
+#include <net/udp.h>
+#include <net/sock.h>
+
+static void wg_packet_send_handshake_initiation(struct wg_peer *peer)
+{
+	struct message_handshake_initiation packet;
+
+	if (!wg_birthdate_has_expired(atomic64_read(&peer->last_sent_handshake),
+				      REKEY_TIMEOUT))
+		return; /* This function is rate limited. */
+
+	atomic64_set(&peer->last_sent_handshake, ktime_get_coarse_boottime_ns());
+	net_dbg_ratelimited("%s: Sending handshake initiation to peer %llu (%pISpfsc)\n",
+			    peer->device->dev->name, peer->internal_id,
+			    &peer->endpoint.addr);
+
+	if (wg_noise_handshake_create_initiation(&packet, &peer->handshake)) {
+		wg_cookie_add_mac_to_packet(&packet, sizeof(packet), peer);
+		wg_timers_any_authenticated_packet_traversal(peer);
+		wg_timers_any_authenticated_packet_sent(peer);
+		atomic64_set(&peer->last_sent_handshake,
+			     ktime_get_coarse_boottime_ns());
+		wg_socket_send_buffer_to_peer(peer, &packet, sizeof(packet),
+					      HANDSHAKE_DSCP);
+		wg_timers_handshake_initiated(peer);
+	}
+}
+
+void wg_packet_handshake_send_worker(struct work_struct *work)
+{
+	struct wg_peer *peer = container_of(work, struct wg_peer,
+					    transmit_handshake_work);
+
+	wg_packet_send_handshake_initiation(peer);
+	wg_peer_put(peer);
+}
+
+void wg_packet_send_queued_handshake_initiation(struct wg_peer *peer,
+						bool is_retry)
+{
+	if (!is_retry)
+		peer->timer_handshake_attempts = 0;
+
+	rcu_read_lock_bh();
+	/* We check last_sent_handshake here in addition to the actual function
+	 * we're queueing up, so that we don't queue things if not strictly
+	 * necessary:
+	 */
+	if (!wg_birthdate_has_expired(atomic64_read(&peer->last_sent_handshake),
+				      REKEY_TIMEOUT) ||
+			unlikely(READ_ONCE(peer->is_dead)))
+		goto out;
+
+	wg_peer_get(peer);
+	/* Queues up calling packet_send_queued_handshakes(peer), where we do a
+	 * peer_put(peer) after:
+	 */
+	if (!queue_work(peer->device->handshake_send_wq,
+			&peer->transmit_handshake_work))
+		/* If the work was already queued, we want to drop the
+		 * extra reference:
+		 */
+		wg_peer_put(peer);
+out:
+	rcu_read_unlock_bh();
+}
+
+void wg_packet_send_handshake_response(struct wg_peer *peer)
+{
+	struct message_handshake_response packet;
+
+	atomic64_set(&peer->last_sent_handshake, ktime_get_coarse_boottime_ns());
+	net_dbg_ratelimited("%s: Sending handshake response to peer %llu (%pISpfsc)\n",
+			    peer->device->dev->name, peer->internal_id,
+			    &peer->endpoint.addr);
+
+	if (wg_noise_handshake_create_response(&packet, &peer->handshake)) {
+		wg_cookie_add_mac_to_packet(&packet, sizeof(packet), peer);
+		if (wg_noise_handshake_begin_session(&peer->handshake,
+						     &peer->keypairs)) {
+			wg_timers_session_derived(peer);
+			wg_timers_any_authenticated_packet_traversal(peer);
+			wg_timers_any_authenticated_packet_sent(peer);
+			atomic64_set(&peer->last_sent_handshake,
+				     ktime_get_coarse_boottime_ns());
+			wg_socket_send_buffer_to_peer(peer, &packet,
+						      sizeof(packet),
+						      HANDSHAKE_DSCP);
+		}
+	}
+}
+
+void wg_packet_send_handshake_cookie(struct wg_device *wg,
+				     struct sk_buff *initiating_skb,
+				     __le32 sender_index)
+{
+	struct message_handshake_cookie packet;
+
+	net_dbg_skb_ratelimited("%s: Sending cookie response for denied handshake message for %pISpfsc\n",
+				wg->dev->name, initiating_skb);
+	wg_cookie_message_create(&packet, initiating_skb, sender_index,
+				 &wg->cookie_checker);
+	wg_socket_send_buffer_as_reply_to_skb(wg, initiating_skb, &packet,
+					      sizeof(packet));
+}
+
+static void keep_key_fresh(struct wg_peer *peer)
+{
+	struct noise_keypair *keypair;
+	bool send;
+
+	rcu_read_lock_bh();
+	keypair = rcu_dereference_bh(peer->keypairs.current_keypair);
+	send = keypair && READ_ONCE(keypair->sending.is_valid) &&
+	       (atomic64_read(&keypair->sending_counter) > REKEY_AFTER_MESSAGES ||
+		(keypair->i_am_the_initiator &&
+		 wg_birthdate_has_expired(keypair->sending.birthdate, REKEY_AFTER_TIME)));
+	rcu_read_unlock_bh();
+
+	if (unlikely(send))
+		wg_packet_send_queued_handshake_initiation(peer, false);
+}
+
+static unsigned int calculate_skb_padding(struct sk_buff *skb)
+{
+	unsigned int padded_size, last_unit = skb->len;
+
+	if (unlikely(!PACKET_CB(skb)->mtu))
+		return ALIGN(last_unit, MESSAGE_PADDING_MULTIPLE) - last_unit;
+
+	/* We do this modulo business with the MTU, just in case the networking
+	 * layer gives us a packet that's bigger than the MTU. In that case, we
+	 * wouldn't want the final subtraction to overflow in the case of the
+	 * padded_size being clamped. Fortunately, that's very rarely the case,
+	 * so we optimize for that not happening.
+	 */
+	if (unlikely(last_unit > PACKET_CB(skb)->mtu))
+		last_unit %= PACKET_CB(skb)->mtu;
+
+	padded_size = min(PACKET_CB(skb)->mtu,
+			  ALIGN(last_unit, MESSAGE_PADDING_MULTIPLE));
+	return padded_size - last_unit;
+}
+
+static bool encrypt_packet(struct sk_buff *skb, struct noise_keypair *keypair)
+{
+	unsigned int padding_len, plaintext_len, trailer_len;
+	struct scatterlist sg[MAX_SKB_FRAGS + 8];
+	struct message_data *header;
+	struct sk_buff *trailer;
+	int num_frags;
+
+	/* Force hash calculation before encryption so that flow analysis is
+	 * consistent over the inner packet.
+	 */
+	skb_get_hash(skb);
+
+	/* Calculate lengths. */
+	padding_len = calculate_skb_padding(skb);
+	trailer_len = padding_len + noise_encrypted_len(0);
+	plaintext_len = skb->len + padding_len;
+
+	/* Expand head section to have room for our header and the network
+	 * stack's headers.
+	 */
+	if (unlikely(skb_cow_head(skb, DATA_PACKET_HEAD_ROOM) < 0))
+		return false;
+
+	/* Finalize checksum calculation for the inner packet, if required. */
+	if (unlikely(skb->ip_summed == CHECKSUM_PARTIAL &&
+		     skb_checksum_help(skb)))
+		return false;
+
+	/* Expand data section to have room for padding and auth tag. */
+	num_frags = skb_cow_data(skb, trailer_len, &trailer);
+	if (unlikely(num_frags < 0 || num_frags > ARRAY_SIZE(sg)))
+		return false;
+
+	/* Set the padding to zeros, and make sure it and the auth tag are part
+	 * of the skb.
+	 */
+	memset(skb_tail_pointer(trailer), 0, padding_len);
+
+	/* Only after checksumming can we safely add on the padding at the end
+	 * and the header.
+	 */
+	skb_set_inner_network_header(skb, 0);
+	header = (struct message_data *)skb_push(skb, sizeof(*header));
+	header->header.type = cpu_to_le32(MESSAGE_DATA);
+	header->key_idx = keypair->remote_index;
+	header->counter = cpu_to_le64(PACKET_CB(skb)->nonce);
+	pskb_put(skb, trailer, trailer_len);
+
+	/* Now we can encrypt the scattergather segments */
+	sg_init_table(sg, num_frags);
+	if (skb_to_sgvec(skb, sg, sizeof(struct message_data),
+			 noise_encrypted_len(plaintext_len)) <= 0)
+		return false;
+	return chacha20poly1305_encrypt_sg_inplace(sg, plaintext_len, NULL, 0,
+						   PACKET_CB(skb)->nonce,
+						   keypair->sending.key);
+}
+
+void wg_packet_send_keepalive(struct wg_peer *peer)
+{
+	struct sk_buff *skb;
+
+	if (skb_queue_empty_lockless(&peer->staged_packet_queue)) {
+		skb = alloc_skb(DATA_PACKET_HEAD_ROOM + MESSAGE_MINIMUM_LENGTH,
+				GFP_ATOMIC);
+		if (unlikely(!skb))
+			return;
+		skb_reserve(skb, DATA_PACKET_HEAD_ROOM);
+		skb->dev = peer->device->dev;
+		PACKET_CB(skb)->mtu = skb->dev->mtu;
+		skb_queue_tail(&peer->staged_packet_queue, skb);
+		net_dbg_ratelimited("%s: Sending keepalive packet to peer %llu (%pISpfsc)\n",
+				    peer->device->dev->name, peer->internal_id,
+				    &peer->endpoint.addr);
+	}
+
+	wg_packet_send_staged_packets(peer);
+}
+
+static void wg_packet_create_data_done(struct wg_peer *peer, struct sk_buff *first)
+{
+	struct sk_buff *skb, *next;
+	bool is_keepalive, data_sent = false;
+
+	wg_timers_any_authenticated_packet_traversal(peer);
+	wg_timers_any_authenticated_packet_sent(peer);
+	skb_list_walk_safe(first, skb, next) {
+		is_keepalive = skb->len == message_data_len(0);
+		if (likely(!wg_socket_send_skb_to_peer(peer, skb,
+				PACKET_CB(skb)->ds) && !is_keepalive))
+			data_sent = true;
+	}
+
+	if (likely(data_sent))
+		wg_timers_data_sent(peer);
+
+	keep_key_fresh(peer);
+}
+
+void wg_packet_tx_worker(struct work_struct *work)
+{
+	struct wg_peer *peer = container_of(work, struct wg_peer, transmit_packet_work);
+	struct noise_keypair *keypair;
+	enum packet_state state;
+	struct sk_buff *first;
+
+	while ((first = wg_prev_queue_peek(&peer->tx_queue)) != NULL &&
+	       (state = atomic_read_acquire(&PACKET_CB(first)->state)) !=
+		       PACKET_STATE_UNCRYPTED) {
+		wg_prev_queue_drop_peeked(&peer->tx_queue);
+		keypair = PACKET_CB(first)->keypair;
+
+		if (likely(state == PACKET_STATE_CRYPTED))
+			wg_packet_create_data_done(peer, first);
+		else
+			kfree_skb_list(first);
+
+		wg_noise_keypair_put(keypair, false);
+		wg_peer_put(peer);
+		if (need_resched())
+			cond_resched();
+	}
+}
+
+void wg_packet_encrypt_worker(struct work_struct *work)
+{
+	struct crypt_queue *queue = container_of(work, struct multicore_worker,
+						 work)->ptr;
+	struct sk_buff *first, *skb, *next;
+
+	while ((first = ptr_ring_consume_bh(&queue->ring)) != NULL) {
+		enum packet_state state = PACKET_STATE_CRYPTED;
+
+		skb_list_walk_safe(first, skb, next) {
+			if (likely(encrypt_packet(skb,
+					PACKET_CB(first)->keypair))) {
+				wg_reset_packet(skb, true);
+			} else {
+				state = PACKET_STATE_DEAD;
+				break;
+			}
+		}
+		wg_queue_enqueue_per_peer_tx(first, state);
+		if (need_resched())
+			cond_resched();
+	}
+}
+
+static void wg_packet_create_data(struct wg_peer *peer, struct sk_buff *first)
+{
+	struct wg_device *wg = peer->device;
+	int ret = -EINVAL;
+
+	rcu_read_lock_bh();
+	if (unlikely(READ_ONCE(peer->is_dead)))
+		goto err;
+
+	ret = wg_queue_enqueue_per_device_and_peer(&wg->encrypt_queue, &peer->tx_queue, first,
+						   wg->packet_crypt_wq);
+	if (unlikely(ret == -EPIPE))
+		wg_queue_enqueue_per_peer_tx(first, PACKET_STATE_DEAD);
+err:
+	rcu_read_unlock_bh();
+	if (likely(!ret || ret == -EPIPE))
+		return;
+	wg_noise_keypair_put(PACKET_CB(first)->keypair, false);
+	wg_peer_put(peer);
+	kfree_skb_list(first);
+}
+
+void wg_packet_purge_staged_packets(struct wg_peer *peer)
+{
+	spin_lock_bh(&peer->staged_packet_queue.lock);
+	DEV_STATS_ADD(peer->device->dev, tx_dropped,
+		      peer->staged_packet_queue.qlen);
+	__skb_queue_purge(&peer->staged_packet_queue);
+	spin_unlock_bh(&peer->staged_packet_queue.lock);
+}
+
+void wg_packet_send_staged_packets(struct wg_peer *peer)
+{
+	struct noise_keypair *keypair;
+	struct sk_buff_head packets;
+	struct sk_buff *skb;
+
+	/* Steal the current queue into our local one. */
+	__skb_queue_head_init(&packets);
+	spin_lock_bh(&peer->staged_packet_queue.lock);
+	skb_queue_splice_init(&peer->staged_packet_queue, &packets);
+	spin_unlock_bh(&peer->staged_packet_queue.lock);
+	if (unlikely(skb_queue_empty(&packets)))
+		return;
+
+	/* First we make sure we have a valid reference to a valid key. */
+	rcu_read_lock_bh();
+	keypair = wg_noise_keypair_get(
+		rcu_dereference_bh(peer->keypairs.current_keypair));
+	rcu_read_unlock_bh();
+	if (unlikely(!keypair))
+		goto out_nokey;
+	if (unlikely(!READ_ONCE(keypair->sending.is_valid)))
+		goto out_nokey;
+	if (unlikely(wg_birthdate_has_expired(keypair->sending.birthdate,
+					      REJECT_AFTER_TIME)))
+		goto out_invalid;
+
+	/* After we know we have a somewhat valid key, we now try to assign
+	 * nonces to all of the packets in the queue. If we can't assign nonces
+	 * for all of them, we just consider it a failure and wait for the next
+	 * handshake.
+	 */
+	skb_queue_walk(&packets, skb) {
+		/* 0 for no outer TOS: no leak. TODO: at some later point, we
+		 * might consider using flowi->tos as outer instead.
+		 */
+		PACKET_CB(skb)->ds = ip_tunnel_ecn_encap(0, ip_hdr(skb), skb);
+		PACKET_CB(skb)->nonce =
+				atomic64_inc_return(&keypair->sending_counter) - 1;
+		if (unlikely(PACKET_CB(skb)->nonce >= REJECT_AFTER_MESSAGES))
+			goto out_invalid;
+	}
+
+	packets.prev->next = NULL;
+	wg_peer_get(keypair->entry.peer);
+	PACKET_CB(packets.next)->keypair = keypair;
+	wg_packet_create_data(peer, packets.next);
+	return;
+
+out_invalid:
+	WRITE_ONCE(keypair->sending.is_valid, false);
+out_nokey:
+	wg_noise_keypair_put(keypair, false);
+
+	/* We orphan the packets if we're waiting on a handshake, so that they
+	 * don't block a socket's pool.
+	 */
+	skb_queue_walk(&packets, skb)
+		skb_orphan(skb);
+	/* Then we put them back on the top of the queue. We're not too
+	 * concerned about accidentally getting things a little out of order if
+	 * packets are being added really fast, because this queue is for before
+	 * packets can even be sent and it's small anyway.
+	 */
+	spin_lock_bh(&peer->staged_packet_queue.lock);
+	skb_queue_splice(&packets, &peer->staged_packet_queue);
+	spin_unlock_bh(&peer->staged_packet_queue.lock);
+
+	/* If we're exiting because there's something wrong with the key, it
+	 * means we should initiate a new handshake.
+	 */
+	wg_packet_send_queued_handshake_initiation(peer, false);
+}