--- /dev/null
+From 4a25324891a32d080589a6e3a4dec2be2d9e3d60 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Tue, 23 Feb 2021 14:18:58 +0100
+Subject: [PATCH] net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before
+ sending
+
+commit ee576c47db60432c37e54b1e2b43a8ca6d3a8dca upstream.
+
+The icmp{,v6}_send functions make all sorts of use of skb->cb, casting
+it with IPCB or IP6CB, assuming the skb to have come directly from the
+inet layer. But when the packet comes from the ndo layer, especially
+when forwarded, there's no telling what might be in skb->cb at that
+point. As a result, the icmp sending code risks reading bogus memory
+contents, which can result in nasty stack overflows such as this one
+reported by a user:
+
+ panic+0x108/0x2ea
+ __stack_chk_fail+0x14/0x20
+ __icmp_send+0x5bd/0x5c0
+ icmp_ndo_send+0x148/0x160
+
+In icmp_send, skb->cb is cast with IPCB and an ip_options struct is read
+from it. The optlen parameter there is of particular note, as it can
+induce writes beyond bounds. There are quite a few ways that can happen
+in __ip_options_echo. For example:
+
+ // sptr/skb are attacker-controlled skb bytes
+ sptr = skb_network_header(skb);
+ // dptr/dopt points to stack memory allocated by __icmp_send
+ dptr = dopt->__data;
+ // sopt is the corrupt skb->cb in question
+ if (sopt->rr) {
+ optlen = sptr[sopt->rr+1]; // corrupt skb->cb + skb->data
+ soffset = sptr[sopt->rr+2]; // corrupt skb->cb + skb->data
+ // this now writes potentially attacker-controlled data, over
+ // flowing the stack:
+ memcpy(dptr, sptr+sopt->rr, optlen);
+ }
+
+In the icmpv6_send case, the story is similar, but not as dire, as only
+IP6CB(skb)->iif and IP6CB(skb)->dsthao are used. The dsthao case is
+worse than the iif case, but it is passed to ipv6_find_tlv, which does
+a bit of bounds checking on the value.
+
+This is easy to simulate by doing a `memset(skb->cb, 0x41,
+sizeof(skb->cb));` before calling icmp{,v6}_ndo_send, and it's only by
+good fortune and the rarity of icmp sending from that context that we've
+avoided reports like this until now. For example, in KASAN:
+
+ BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0xa0e/0x12b0
+ Write of size 38 at addr ffff888006f1f80e by task ping/89
+ CPU: 2 PID: 89 Comm: ping Not tainted 5.10.0-rc7-debug+ #5
+ Call Trace:
+ dump_stack+0x9a/0xcc
+ print_address_description.constprop.0+0x1a/0x160
+ __kasan_report.cold+0x20/0x38
+ kasan_report+0x32/0x40
+ check_memory_region+0x145/0x1a0
+ memcpy+0x39/0x60
+ __ip_options_echo+0xa0e/0x12b0
+ __icmp_send+0x744/0x1700
+
+Actually, out of the 4 drivers that do this, only gtp zeroed the cb for
+the v4 case, while the rest did not. So this commit actually removes the
+gtp-specific zeroing, while putting the code where it belongs in the
+shared infrastructure of icmp{,v6}_ndo_send.
+
+This commit fixes the issue by passing an empty IPCB or IP6CB along to
+the functions that actually do the work. For the icmp_send, this was
+already trivial, thanks to __icmp_send providing the plumbing function.
+For icmpv6_send, this required a tiny bit of refactoring to make it
+behave like the v4 case, after which it was straight forward.
+
+Fixes: a2b78e9b2cac ("sunvnet: generate ICMP PTMUD messages for smaller port MTUs")
+Reported-by: SinYu <liuxyon@gmail.com>
+Reviewed-by: Willem de Bruijn <willemb@google.com>
+Link: https://lore.kernel.org/netdev/CAF=yD-LOF116aHub6RMe8vB8ZpnrrnoTdqhobEx+bvoA8AsP0w@mail.gmail.com/T/
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Link: https://lore.kernel.org/r/20210223131858.72082-1-Jason@zx2c4.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+[Jason: backported to 5.10]
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ include/linux/icmpv6.h | 17 ++++++++++++++---
+ include/linux/ipv6.h | 1 -
+ include/net/icmp.h | 6 +++++-
+ net/ipv4/icmp.c | 5 +++--
+ net/ipv6/icmp.c | 16 ++++++++--------
+ net/ipv6/ip6_icmp.c | 12 +++++++-----
+ 6 files changed, 37 insertions(+), 20 deletions(-)
+
+--- a/drivers/net/gtp.c
++++ b/drivers/net/gtp.c
+@@ -539,7 +539,6 @@ static int gtp_build_skb_ip4(struct sk_b
+ if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
+ mtu < ntohs(iph->tot_len)) {
+ netdev_dbg(dev, "packet too big, fragmentation needed\n");
+- memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+ icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+ htonl(mtu));
+ goto err_rt;
+--- a/include/linux/icmpv6.h
++++ b/include/linux/icmpv6.h
+@@ -3,6 +3,7 @@
+ #define _LINUX_ICMPV6_H
+
+ #include <linux/skbuff.h>
++#include <linux/ipv6.h>
+ #include <uapi/linux/icmpv6.h>
+
+ static inline struct icmp6hdr *icmp6_hdr(const struct sk_buff *skb)
+@@ -15,13 +16,16 @@ static inline struct icmp6hdr *icmp6_hdr
+ #if IS_ENABLED(CONFIG_IPV6)
+
+ typedef void ip6_icmp_send_t(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+- const struct in6_addr *force_saddr);
++ const struct in6_addr *force_saddr,
++ const struct inet6_skb_parm *parm);
+ #if IS_BUILTIN(CONFIG_IPV6)
+ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+- const struct in6_addr *force_saddr);
+-static inline void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
++ const struct in6_addr *force_saddr,
++ const struct inet6_skb_parm *parm);
++static inline void __icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
++ const struct inet6_skb_parm *parm)
+ {
+- icmp6_send(skb, type, code, info, NULL);
++ icmp6_send(skb, type, code, info, NULL, parm);
+ }
+ static inline int inet6_register_icmp_sender(ip6_icmp_send_t *fn)
+ {
+@@ -34,18 +38,28 @@ static inline int inet6_unregister_icmp_
+ return 0;
+ }
+ #else
+-extern void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info);
++extern void __icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
++ const struct inet6_skb_parm *parm);
+ extern int inet6_register_icmp_sender(ip6_icmp_send_t *fn);
+ extern int inet6_unregister_icmp_sender(ip6_icmp_send_t *fn);
+ #endif
+
++static inline void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
++{
++ __icmpv6_send(skb, type, code, info, IP6CB(skb));
++}
++
+ int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
+ unsigned int data_len);
+
+ #if IS_ENABLED(CONFIG_NF_NAT)
+ void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info);
+ #else
+-#define icmpv6_ndo_send icmpv6_send
++static inline void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info)
++{
++ struct inet6_skb_parm parm = { 0 };
++ __icmpv6_send(skb_in, type, code, info, &parm);
++}
+ #endif
+
+ #else
+--- a/include/linux/ipv6.h
++++ b/include/linux/ipv6.h
+@@ -84,7 +84,6 @@ struct ipv6_params {
+ __s32 autoconf;
+ };
+ extern struct ipv6_params ipv6_defaults;
+-#include <linux/icmpv6.h>
+ #include <linux/tcp.h>
+ #include <linux/udp.h>
+
+--- a/include/net/icmp.h
++++ b/include/net/icmp.h
+@@ -46,7 +46,11 @@ static inline void icmp_send(struct sk_b
+ #if IS_ENABLED(CONFIG_NF_NAT)
+ void icmp_ndo_send(struct sk_buff *skb_in, int type, int code, __be32 info);
+ #else
+-#define icmp_ndo_send icmp_send
++static inline void icmp_ndo_send(struct sk_buff *skb_in, int type, int code, __be32 info)
++{
++ struct ip_options opts = { 0 };
++ __icmp_send(skb_in, type, code, info, &opts);
++}
+ #endif
+
+ int icmp_rcv(struct sk_buff *skb);
+--- a/net/ipv4/icmp.c
++++ b/net/ipv4/icmp.c
+@@ -775,13 +775,14 @@ EXPORT_SYMBOL(__icmp_send);
+ void icmp_ndo_send(struct sk_buff *skb_in, int type, int code, __be32 info)
+ {
+ struct sk_buff *cloned_skb = NULL;
++ struct ip_options opts = { 0 };
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct;
+ __be32 orig_ip;
+
+ ct = nf_ct_get(skb_in, &ctinfo);
+ if (!ct || !(ct->status & IPS_SRC_NAT)) {
+- icmp_send(skb_in, type, code, info);
++ __icmp_send(skb_in, type, code, info, &opts);
+ return;
+ }
+
+@@ -796,7 +797,7 @@ void icmp_ndo_send(struct sk_buff *skb_i
+
+ orig_ip = ip_hdr(skb_in)->saddr;
+ ip_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.ip;
+- icmp_send(skb_in, type, code, info);
++ __icmp_send(skb_in, type, code, info, &opts);
+ ip_hdr(skb_in)->saddr = orig_ip;
+ out:
+ consume_skb(cloned_skb);
+--- a/net/ipv6/icmp.c
++++ b/net/ipv6/icmp.c
+@@ -331,10 +331,9 @@ static int icmpv6_getfrag(void *from, ch
+ }
+
+ #if IS_ENABLED(CONFIG_IPV6_MIP6)
+-static void mip6_addr_swap(struct sk_buff *skb)
++static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt)
+ {
+ struct ipv6hdr *iph = ipv6_hdr(skb);
+- struct inet6_skb_parm *opt = IP6CB(skb);
+ struct ipv6_destopt_hao *hao;
+ struct in6_addr tmp;
+ int off;
+@@ -351,7 +350,7 @@ static void mip6_addr_swap(struct sk_buf
+ }
+ }
+ #else
+-static inline void mip6_addr_swap(struct sk_buff *skb) {}
++static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {}
+ #endif
+
+ static struct dst_entry *icmpv6_route_lookup(struct net *net,
+@@ -446,7 +445,8 @@ static int icmp6_iif(const struct sk_buf
+ * Send an ICMP message in response to a packet in error
+ */
+ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+- const struct in6_addr *force_saddr)
++ const struct in6_addr *force_saddr,
++ const struct inet6_skb_parm *parm)
+ {
+ struct inet6_dev *idev = NULL;
+ struct ipv6hdr *hdr = ipv6_hdr(skb);
+@@ -542,7 +542,7 @@ void icmp6_send(struct sk_buff *skb, u8
+ if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
+ goto out_bh_enable;
+
+- mip6_addr_swap(skb);
++ mip6_addr_swap(skb, parm);
+
+ sk = icmpv6_xmit_lock(net);
+ if (!sk)
+@@ -559,7 +559,7 @@ void icmp6_send(struct sk_buff *skb, u8
+ /* select a more meaningful saddr from input if */
+ struct net_device *in_netdev;
+
+- in_netdev = dev_get_by_index(net, IP6CB(skb)->iif);
++ in_netdev = dev_get_by_index(net, parm->iif);
+ if (in_netdev) {
+ ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
+ inet6_sk(sk)->srcprefs,
+@@ -640,7 +640,7 @@ EXPORT_SYMBOL(icmp6_send);
+ */
+ void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
+ {
+- icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
++ icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb));
+ kfree_skb(skb);
+ }
+
+@@ -697,10 +697,10 @@ int ip6_err_gen_icmpv6_unreach(struct sk
+ }
+ if (type == ICMP_TIME_EXCEEDED)
+ icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
+- info, &temp_saddr);
++ info, &temp_saddr, IP6CB(skb2));
+ else
+ icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
+- info, &temp_saddr);
++ info, &temp_saddr, IP6CB(skb2));
+ if (rt)
+ ip6_rt_put(rt);
+
+--- a/net/ipv6/ip6_icmp.c
++++ b/net/ipv6/ip6_icmp.c
+@@ -33,23 +33,25 @@ int inet6_unregister_icmp_sender(ip6_icm
+ }
+ EXPORT_SYMBOL(inet6_unregister_icmp_sender);
+
+-void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
++void __icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
++ const struct inet6_skb_parm *parm)
+ {
+ ip6_icmp_send_t *send;
+
+ rcu_read_lock();
+ send = rcu_dereference(ip6_icmp_send);
+ if (send)
+- send(skb, type, code, info, NULL);
++ send(skb, type, code, info, NULL, parm);
+ rcu_read_unlock();
+ }
+-EXPORT_SYMBOL(icmpv6_send);
++EXPORT_SYMBOL(__icmpv6_send);
+ #endif
+
+ #if IS_ENABLED(CONFIG_NF_NAT)
+ #include <net/netfilter/nf_conntrack.h>
+ void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info)
+ {
++ struct inet6_skb_parm parm = { 0 };
+ struct sk_buff *cloned_skb = NULL;
+ enum ip_conntrack_info ctinfo;
+ struct in6_addr orig_ip;
+@@ -57,7 +59,7 @@ void icmpv6_ndo_send(struct sk_buff *skb
+
+ ct = nf_ct_get(skb_in, &ctinfo);
+ if (!ct || !(ct->status & IPS_SRC_NAT)) {
+- icmpv6_send(skb_in, type, code, info);
++ __icmpv6_send(skb_in, type, code, info, &parm);
+ return;
+ }
+
+@@ -72,7 +74,7 @@ void icmpv6_ndo_send(struct sk_buff *skb
+
+ orig_ip = ipv6_hdr(skb_in)->saddr;
+ ipv6_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.in6;
+- icmpv6_send(skb_in, type, code, info);
++ __icmpv6_send(skb_in, type, code, info, &parm);
+ ipv6_hdr(skb_in)->saddr = orig_ip;
+ out:
+ consume_skb(cloned_skb);
--- /dev/null
+From 1771bbcc5bc99f569dd82ec9e1b7c397a2fb50ac Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Mon, 22 Feb 2021 17:25:48 +0100
+Subject: [PATCH] wireguard: queueing: get rid of per-peer ring buffers
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+commit 8b5553ace83cced775eefd0f3f18b5c6214ccf7a upstream.
+
+Having two ring buffers per-peer means that every peer results in two
+massive ring allocations. On an 8-core x86_64 machine, this commit
+reduces the per-peer allocation from 18,688 bytes to 1,856 bytes, which
+is an 90% reduction. Ninety percent! With some single-machine
+deployments approaching 500,000 peers, we're talking about a reduction
+from 7 gigs of memory down to 700 megs of memory.
+
+In order to get rid of these per-peer allocations, this commit switches
+to using a list-based queueing approach. Currently GSO fragments are
+chained together using the skb->next pointer (the skb_list_* singly
+linked list approach), so we form the per-peer queue around the unused
+skb->prev pointer (which sort of makes sense because the links are
+pointing backwards). Use of skb_queue_* is not possible here, because
+that is based on doubly linked lists and spinlocks. Multiple cores can
+write into the queue at any given time, because its writes occur in the
+start_xmit path or in the udp_recv path. But reads happen in a single
+workqueue item per-peer, amounting to a multi-producer, single-consumer
+paradigm.
+
+The MPSC queue is implemented locklessly and never blocks. However, it
+is not linearizable (though it is serializable), with a very tight and
+unlikely race on writes, which, when hit (some tiny fraction of the
+0.15% of partial adds on a fully loaded 16-core x86_64 system), causes
+the queue reader to terminate early. However, because every packet sent
+queues up the same workqueue item after it is fully added, the worker
+resumes again, and stopping early isn't actually a problem, since at
+that point the packet wouldn't have yet been added to the encryption
+queue. These properties allow us to avoid disabling interrupts or
+spinning. The design is based on Dmitry Vyukov's algorithm [1].
+
+Performance-wise, ordinarily list-based queues aren't preferable to
+ringbuffers, because of cache misses when following pointers around.
+However, we *already* have to follow the adjacent pointers when working
+through fragments, so there shouldn't actually be any change there. A
+potential downside is that dequeueing is a bit more complicated, but the
+ptr_ring structure used prior had a spinlock when dequeueing, so all and
+all the difference appears to be a wash.
+
+Actually, from profiling, the biggest performance hit, by far, of this
+commit winds up being atomic_add_unless(count, 1, max) and atomic_
+dec(count), which account for the majority of CPU time, according to
+perf. In that sense, the previous ring buffer was superior in that it
+could check if it was full by head==tail, which the list-based approach
+cannot do.
+
+But all and all, this enables us to get massive memory savings, allowing
+WireGuard to scale for real world deployments, without taking much of a
+performance hit.
+
+[1] http://www.1024cores.net/home/lock-free-algorithms/queues/intrusive-mpsc-node-based-queue
+
+Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
+Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/device.c | 12 ++---
+ drivers/net/wireguard/device.h | 15 +++---
+ drivers/net/wireguard/peer.c | 28 ++++-------
+ drivers/net/wireguard/peer.h | 4 +-
+ drivers/net/wireguard/queueing.c | 86 +++++++++++++++++++++++++-------
+ drivers/net/wireguard/queueing.h | 45 ++++++++++++-----
+ drivers/net/wireguard/receive.c | 16 +++---
+ drivers/net/wireguard/send.c | 31 ++++--------
+ 8 files changed, 144 insertions(+), 93 deletions(-)
+
+--- a/drivers/net/wireguard/device.c
++++ b/drivers/net/wireguard/device.c
+@@ -235,8 +235,8 @@ static void wg_destruct(struct net_devic
+ destroy_workqueue(wg->handshake_receive_wq);
+ destroy_workqueue(wg->handshake_send_wq);
+ destroy_workqueue(wg->packet_crypt_wq);
+- wg_packet_queue_free(&wg->decrypt_queue, true);
+- wg_packet_queue_free(&wg->encrypt_queue, true);
++ wg_packet_queue_free(&wg->decrypt_queue);
++ wg_packet_queue_free(&wg->encrypt_queue);
+ rcu_barrier(); /* Wait for all the peers to be actually freed. */
+ wg_ratelimiter_uninit();
+ memzero_explicit(&wg->static_identity, sizeof(wg->static_identity));
+@@ -338,12 +338,12 @@ static int wg_newlink(struct net *src_ne
+ goto err_destroy_handshake_send;
+
+ ret = wg_packet_queue_init(&wg->encrypt_queue, wg_packet_encrypt_worker,
+- true, MAX_QUEUED_PACKETS);
++ MAX_QUEUED_PACKETS);
+ if (ret < 0)
+ goto err_destroy_packet_crypt;
+
+ ret = wg_packet_queue_init(&wg->decrypt_queue, wg_packet_decrypt_worker,
+- true, MAX_QUEUED_PACKETS);
++ MAX_QUEUED_PACKETS);
+ if (ret < 0)
+ goto err_free_encrypt_queue;
+
+@@ -368,9 +368,9 @@ static int wg_newlink(struct net *src_ne
+ err_uninit_ratelimiter:
+ wg_ratelimiter_uninit();
+ err_free_decrypt_queue:
+- wg_packet_queue_free(&wg->decrypt_queue, true);
++ wg_packet_queue_free(&wg->decrypt_queue);
+ err_free_encrypt_queue:
+- wg_packet_queue_free(&wg->encrypt_queue, true);
++ wg_packet_queue_free(&wg->encrypt_queue);
+ err_destroy_packet_crypt:
+ destroy_workqueue(wg->packet_crypt_wq);
+ err_destroy_handshake_send:
+--- a/drivers/net/wireguard/device.h
++++ b/drivers/net/wireguard/device.h
+@@ -27,13 +27,14 @@ struct multicore_worker {
+
+ struct crypt_queue {
+ struct ptr_ring ring;
+- union {
+- struct {
+- struct multicore_worker __percpu *worker;
+- int last_cpu;
+- };
+- struct work_struct work;
+- };
++ struct multicore_worker __percpu *worker;
++ int last_cpu;
++};
++
++struct prev_queue {
++ struct sk_buff *head, *tail, *peeked;
++ struct { struct sk_buff *next, *prev; } empty; // Match first 2 members of struct sk_buff.
++ atomic_t count;
+ };
+
+ struct wg_device {
+--- a/drivers/net/wireguard/peer.c
++++ b/drivers/net/wireguard/peer.c
+@@ -32,27 +32,22 @@ struct wg_peer *wg_peer_create(struct wg
+ peer = kzalloc(sizeof(*peer), GFP_KERNEL);
+ if (unlikely(!peer))
+ return ERR_PTR(ret);
+- peer->device = wg;
++ if (dst_cache_init(&peer->endpoint_cache, GFP_KERNEL))
++ goto err;
+
++ peer->device = wg;
+ wg_noise_handshake_init(&peer->handshake, &wg->static_identity,
+ public_key, preshared_key, peer);
+- if (dst_cache_init(&peer->endpoint_cache, GFP_KERNEL))
+- goto err_1;
+- if (wg_packet_queue_init(&peer->tx_queue, wg_packet_tx_worker, false,
+- MAX_QUEUED_PACKETS))
+- goto err_2;
+- if (wg_packet_queue_init(&peer->rx_queue, NULL, false,
+- MAX_QUEUED_PACKETS))
+- goto err_3;
+-
+ peer->internal_id = atomic64_inc_return(&peer_counter);
+ peer->serial_work_cpu = nr_cpumask_bits;
+ wg_cookie_init(&peer->latest_cookie);
+ wg_timers_init(peer);
+ wg_cookie_checker_precompute_peer_keys(peer);
+ spin_lock_init(&peer->keypairs.keypair_update_lock);
+- INIT_WORK(&peer->transmit_handshake_work,
+- wg_packet_handshake_send_worker);
++ INIT_WORK(&peer->transmit_handshake_work, wg_packet_handshake_send_worker);
++ INIT_WORK(&peer->transmit_packet_work, wg_packet_tx_worker);
++ wg_prev_queue_init(&peer->tx_queue);
++ wg_prev_queue_init(&peer->rx_queue);
+ rwlock_init(&peer->endpoint_lock);
+ kref_init(&peer->refcount);
+ skb_queue_head_init(&peer->staged_packet_queue);
+@@ -68,11 +63,7 @@ struct wg_peer *wg_peer_create(struct wg
+ pr_debug("%s: Peer %llu created\n", wg->dev->name, peer->internal_id);
+ return peer;
+
+-err_3:
+- wg_packet_queue_free(&peer->tx_queue, false);
+-err_2:
+- dst_cache_destroy(&peer->endpoint_cache);
+-err_1:
++err:
+ kfree(peer);
+ return ERR_PTR(ret);
+ }
+@@ -197,8 +188,7 @@ static void rcu_release(struct rcu_head
+ struct wg_peer *peer = container_of(rcu, struct wg_peer, rcu);
+
+ dst_cache_destroy(&peer->endpoint_cache);
+- wg_packet_queue_free(&peer->rx_queue, false);
+- wg_packet_queue_free(&peer->tx_queue, false);
++ WARN_ON(wg_prev_queue_peek(&peer->tx_queue) || wg_prev_queue_peek(&peer->rx_queue));
+
+ /* The final zeroing takes care of clearing any remaining handshake key
+ * material and other potentially sensitive information.
+--- a/drivers/net/wireguard/peer.h
++++ b/drivers/net/wireguard/peer.h
+@@ -36,7 +36,7 @@ struct endpoint {
+
+ struct wg_peer {
+ struct wg_device *device;
+- struct crypt_queue tx_queue, rx_queue;
++ struct prev_queue tx_queue, rx_queue;
+ struct sk_buff_head staged_packet_queue;
+ int serial_work_cpu;
+ bool is_dead;
+@@ -46,7 +46,7 @@ struct wg_peer {
+ rwlock_t endpoint_lock;
+ struct noise_handshake handshake;
+ atomic64_t last_sent_handshake;
+- struct work_struct transmit_handshake_work, clear_peer_work;
++ struct work_struct transmit_handshake_work, clear_peer_work, transmit_packet_work;
+ struct cookie latest_cookie;
+ struct hlist_node pubkey_hash;
+ u64 rx_bytes, tx_bytes;
+--- a/drivers/net/wireguard/queueing.c
++++ b/drivers/net/wireguard/queueing.c
+@@ -9,8 +9,7 @@ struct multicore_worker __percpu *
+ wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr)
+ {
+ int cpu;
+- struct multicore_worker __percpu *worker =
+- alloc_percpu(struct multicore_worker);
++ struct multicore_worker __percpu *worker = alloc_percpu(struct multicore_worker);
+
+ if (!worker)
+ return NULL;
+@@ -23,7 +22,7 @@ wg_packet_percpu_multicore_worker_alloc(
+ }
+
+ int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function,
+- bool multicore, unsigned int len)
++ unsigned int len)
+ {
+ int ret;
+
+@@ -31,25 +30,78 @@ int wg_packet_queue_init(struct crypt_qu
+ ret = ptr_ring_init(&queue->ring, len, GFP_KERNEL);
+ if (ret)
+ return ret;
+- if (function) {
+- if (multicore) {
+- queue->worker = wg_packet_percpu_multicore_worker_alloc(
+- function, queue);
+- if (!queue->worker) {
+- ptr_ring_cleanup(&queue->ring, NULL);
+- return -ENOMEM;
+- }
+- } else {
+- INIT_WORK(&queue->work, function);
+- }
++ queue->worker = wg_packet_percpu_multicore_worker_alloc(function, queue);
++ if (!queue->worker) {
++ ptr_ring_cleanup(&queue->ring, NULL);
++ return -ENOMEM;
+ }
+ return 0;
+ }
+
+-void wg_packet_queue_free(struct crypt_queue *queue, bool multicore)
++void wg_packet_queue_free(struct crypt_queue *queue)
+ {
+- if (multicore)
+- free_percpu(queue->worker);
++ free_percpu(queue->worker);
+ WARN_ON(!__ptr_ring_empty(&queue->ring));
+ ptr_ring_cleanup(&queue->ring, NULL);
+ }
++
++#define NEXT(skb) ((skb)->prev)
++#define STUB(queue) ((struct sk_buff *)&queue->empty)
++
++void wg_prev_queue_init(struct prev_queue *queue)
++{
++ NEXT(STUB(queue)) = NULL;
++ queue->head = queue->tail = STUB(queue);
++ queue->peeked = NULL;
++ atomic_set(&queue->count, 0);
++ BUILD_BUG_ON(
++ offsetof(struct sk_buff, next) != offsetof(struct prev_queue, empty.next) -
++ offsetof(struct prev_queue, empty) ||
++ offsetof(struct sk_buff, prev) != offsetof(struct prev_queue, empty.prev) -
++ offsetof(struct prev_queue, empty));
++}
++
++static void __wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb)
++{
++ WRITE_ONCE(NEXT(skb), NULL);
++ WRITE_ONCE(NEXT(xchg_release(&queue->head, skb)), skb);
++}
++
++bool wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb)
++{
++ if (!atomic_add_unless(&queue->count, 1, MAX_QUEUED_PACKETS))
++ return false;
++ __wg_prev_queue_enqueue(queue, skb);
++ return true;
++}
++
++struct sk_buff *wg_prev_queue_dequeue(struct prev_queue *queue)
++{
++ struct sk_buff *tail = queue->tail, *next = smp_load_acquire(&NEXT(tail));
++
++ if (tail == STUB(queue)) {
++ if (!next)
++ return NULL;
++ queue->tail = next;
++ tail = next;
++ next = smp_load_acquire(&NEXT(next));
++ }
++ if (next) {
++ queue->tail = next;
++ atomic_dec(&queue->count);
++ return tail;
++ }
++ if (tail != READ_ONCE(queue->head))
++ return NULL;
++ __wg_prev_queue_enqueue(queue, STUB(queue));
++ next = smp_load_acquire(&NEXT(tail));
++ if (next) {
++ queue->tail = next;
++ atomic_dec(&queue->count);
++ return tail;
++ }
++ return NULL;
++}
++
++#undef NEXT
++#undef STUB
+--- a/drivers/net/wireguard/queueing.h
++++ b/drivers/net/wireguard/queueing.h
+@@ -17,12 +17,13 @@ struct wg_device;
+ struct wg_peer;
+ struct multicore_worker;
+ struct crypt_queue;
++struct prev_queue;
+ struct sk_buff;
+
+ /* queueing.c APIs: */
+ int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function,
+- bool multicore, unsigned int len);
+-void wg_packet_queue_free(struct crypt_queue *queue, bool multicore);
++ unsigned int len);
++void wg_packet_queue_free(struct crypt_queue *queue);
+ struct multicore_worker __percpu *
+ wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr);
+
+@@ -135,8 +136,31 @@ static inline int wg_cpumask_next_online
+ return cpu;
+ }
+
++void wg_prev_queue_init(struct prev_queue *queue);
++
++/* Multi producer */
++bool wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb);
++
++/* Single consumer */
++struct sk_buff *wg_prev_queue_dequeue(struct prev_queue *queue);
++
++/* Single consumer */
++static inline struct sk_buff *wg_prev_queue_peek(struct prev_queue *queue)
++{
++ if (queue->peeked)
++ return queue->peeked;
++ queue->peeked = wg_prev_queue_dequeue(queue);
++ return queue->peeked;
++}
++
++/* Single consumer */
++static inline void wg_prev_queue_drop_peeked(struct prev_queue *queue)
++{
++ queue->peeked = NULL;
++}
++
+ static inline int wg_queue_enqueue_per_device_and_peer(
+- struct crypt_queue *device_queue, struct crypt_queue *peer_queue,
++ struct crypt_queue *device_queue, struct prev_queue *peer_queue,
+ struct sk_buff *skb, struct workqueue_struct *wq, int *next_cpu)
+ {
+ int cpu;
+@@ -145,8 +169,9 @@ static inline int wg_queue_enqueue_per_d
+ /* We first queue this up for the peer ingestion, but the consumer
+ * will wait for the state to change to CRYPTED or DEAD before.
+ */
+- if (unlikely(ptr_ring_produce_bh(&peer_queue->ring, skb)))
++ if (unlikely(!wg_prev_queue_enqueue(peer_queue, skb)))
+ return -ENOSPC;
++
+ /* Then we queue it up in the device queue, which consumes the
+ * packet as soon as it can.
+ */
+@@ -157,9 +182,7 @@ static inline int wg_queue_enqueue_per_d
+ return 0;
+ }
+
+-static inline void wg_queue_enqueue_per_peer(struct crypt_queue *queue,
+- struct sk_buff *skb,
+- enum packet_state state)
++static inline void wg_queue_enqueue_per_peer_tx(struct sk_buff *skb, enum packet_state state)
+ {
+ /* We take a reference, because as soon as we call atomic_set, the
+ * peer can be freed from below us.
+@@ -167,14 +190,12 @@ static inline void wg_queue_enqueue_per_
+ struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb));
+
+ atomic_set_release(&PACKET_CB(skb)->state, state);
+- queue_work_on(wg_cpumask_choose_online(&peer->serial_work_cpu,
+- peer->internal_id),
+- peer->device->packet_crypt_wq, &queue->work);
++ queue_work_on(wg_cpumask_choose_online(&peer->serial_work_cpu, peer->internal_id),
++ peer->device->packet_crypt_wq, &peer->transmit_packet_work);
+ wg_peer_put(peer);
+ }
+
+-static inline void wg_queue_enqueue_per_peer_napi(struct sk_buff *skb,
+- enum packet_state state)
++static inline void wg_queue_enqueue_per_peer_rx(struct sk_buff *skb, enum packet_state state)
+ {
+ /* We take a reference, because as soon as we call atomic_set, the
+ * peer can be freed from below us.
+--- a/drivers/net/wireguard/receive.c
++++ b/drivers/net/wireguard/receive.c
+@@ -444,7 +444,6 @@ packet_processed:
+ int wg_packet_rx_poll(struct napi_struct *napi, int budget)
+ {
+ struct wg_peer *peer = container_of(napi, struct wg_peer, napi);
+- struct crypt_queue *queue = &peer->rx_queue;
+ struct noise_keypair *keypair;
+ struct endpoint endpoint;
+ enum packet_state state;
+@@ -455,11 +454,10 @@ int wg_packet_rx_poll(struct napi_struct
+ if (unlikely(budget <= 0))
+ return 0;
+
+- while ((skb = __ptr_ring_peek(&queue->ring)) != NULL &&
++ while ((skb = wg_prev_queue_peek(&peer->rx_queue)) != NULL &&
+ (state = atomic_read_acquire(&PACKET_CB(skb)->state)) !=
+ PACKET_STATE_UNCRYPTED) {
+- __ptr_ring_discard_one(&queue->ring);
+- peer = PACKET_PEER(skb);
++ wg_prev_queue_drop_peeked(&peer->rx_queue);
+ keypair = PACKET_CB(skb)->keypair;
+ free = true;
+
+@@ -508,7 +506,7 @@ void wg_packet_decrypt_worker(struct wor
+ enum packet_state state =
+ likely(decrypt_packet(skb, PACKET_CB(skb)->keypair)) ?
+ PACKET_STATE_CRYPTED : PACKET_STATE_DEAD;
+- wg_queue_enqueue_per_peer_napi(skb, state);
++ wg_queue_enqueue_per_peer_rx(skb, state);
+ if (need_resched())
+ cond_resched();
+ }
+@@ -531,12 +529,10 @@ static void wg_packet_consume_data(struc
+ if (unlikely(READ_ONCE(peer->is_dead)))
+ goto err;
+
+- ret = wg_queue_enqueue_per_device_and_peer(&wg->decrypt_queue,
+- &peer->rx_queue, skb,
+- wg->packet_crypt_wq,
+- &wg->decrypt_queue.last_cpu);
++ ret = wg_queue_enqueue_per_device_and_peer(&wg->decrypt_queue, &peer->rx_queue, skb,
++ wg->packet_crypt_wq, &wg->decrypt_queue.last_cpu);
+ if (unlikely(ret == -EPIPE))
+- wg_queue_enqueue_per_peer_napi(skb, PACKET_STATE_DEAD);
++ wg_queue_enqueue_per_peer_rx(skb, PACKET_STATE_DEAD);
+ if (likely(!ret || ret == -EPIPE)) {
+ rcu_read_unlock_bh();
+ return;
+--- a/drivers/net/wireguard/send.c
++++ b/drivers/net/wireguard/send.c
+@@ -239,8 +239,7 @@ void wg_packet_send_keepalive(struct wg_
+ wg_packet_send_staged_packets(peer);
+ }
+
+-static void wg_packet_create_data_done(struct sk_buff *first,
+- struct wg_peer *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;
+@@ -262,22 +261,19 @@ static void wg_packet_create_data_done(s
+
+ void wg_packet_tx_worker(struct work_struct *work)
+ {
+- struct crypt_queue *queue = container_of(work, struct crypt_queue,
+- 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;
+- struct wg_peer *peer;
+
+- while ((first = __ptr_ring_peek(&queue->ring)) != NULL &&
++ while ((first = wg_prev_queue_peek(&peer->tx_queue)) != NULL &&
+ (state = atomic_read_acquire(&PACKET_CB(first)->state)) !=
+ PACKET_STATE_UNCRYPTED) {
+- __ptr_ring_discard_one(&queue->ring);
+- peer = PACKET_PEER(first);
++ wg_prev_queue_drop_peeked(&peer->tx_queue);
+ keypair = PACKET_CB(first)->keypair;
+
+ if (likely(state == PACKET_STATE_CRYPTED))
+- wg_packet_create_data_done(first, peer);
++ wg_packet_create_data_done(peer, first);
+ else
+ kfree_skb_list(first);
+
+@@ -306,16 +302,14 @@ void wg_packet_encrypt_worker(struct wor
+ break;
+ }
+ }
+- wg_queue_enqueue_per_peer(&PACKET_PEER(first)->tx_queue, first,
+- state);
++ wg_queue_enqueue_per_peer_tx(first, state);
+ if (need_resched())
+ cond_resched();
+ }
+ }
+
+-static void wg_packet_create_data(struct sk_buff *first)
++static void wg_packet_create_data(struct wg_peer *peer, struct sk_buff *first)
+ {
+- struct wg_peer *peer = PACKET_PEER(first);
+ struct wg_device *wg = peer->device;
+ int ret = -EINVAL;
+
+@@ -323,13 +317,10 @@ static void wg_packet_create_data(struct
+ 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,
+- &wg->encrypt_queue.last_cpu);
++ ret = wg_queue_enqueue_per_device_and_peer(&wg->encrypt_queue, &peer->tx_queue, first,
++ wg->packet_crypt_wq, &wg->encrypt_queue.last_cpu);
+ if (unlikely(ret == -EPIPE))
+- wg_queue_enqueue_per_peer(&peer->tx_queue, first,
+- PACKET_STATE_DEAD);
++ wg_queue_enqueue_per_peer_tx(first, PACKET_STATE_DEAD);
+ err:
+ rcu_read_unlock_bh();
+ if (likely(!ret || ret == -EPIPE))
+@@ -393,7 +384,7 @@ void wg_packet_send_staged_packets(struc
+ packets.prev->next = NULL;
+ wg_peer_get(keypair->entry.peer);
+ PACKET_CB(packets.next)->keypair = keypair;
+- wg_packet_create_data(packets.next);
++ wg_packet_create_data(peer, packets.next);
+ return;
+
+ out_invalid: