kernel-5.4: backport latest patches for wireguard

These are the latest patches that just landed upstream for 5.13, will be
backported by Greg into 5.10 (because of stable@), and are now in the
5.4 backport branch of wireguard: https://git.zx2c4.com/wireguard-linux/log/?h=backport-5.4.y

Cc: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Stijn Segers <foss@volatilesystems.org>

12 files changed, 1514 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/080-wireguard-0124-crypto-mips-poly1305-enable-for-all-MIPS-processors.patch b/target/linux/generic/backport-5.4/080-wireguard-0124-crypto-mips-poly1305-enable-for-all-MIPS-processors.patch
new file mode 100644
index 0000000000..c0ee841b02
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0124-crypto-mips-poly1305-enable-for-all-MIPS-processors.patch
@@ -0,0 +1,60 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Maciej W. Rozycki" <macro@orcam.me.uk>
+Date: Thu, 11 Mar 2021 21:50:47 -0700
+Subject: [PATCH] crypto: mips/poly1305 - enable for all MIPS processors
+
+commit 6c810cf20feef0d4338e9b424ab7f2644a8b353e upstream.
+
+The MIPS Poly1305 implementation is generic MIPS code written such as to
+support down to the original MIPS I and MIPS III ISA for the 32-bit and
+64-bit variant respectively.  Lift the current limitation then to enable
+code for MIPSr1 ISA or newer processors only and have it available for
+all MIPS processors.
+
+Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
+Fixes: a11d055e7a64 ("crypto: mips/poly1305 - incorporate OpenSSL/CRYPTOGAMS optimized implementation")
+Cc: stable@vger.kernel.org # v5.5+
+Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ arch/mips/crypto/Makefile | 4 ++--
+ crypto/Kconfig            | 2 +-
+ drivers/net/Kconfig       | 2 +-
+ 3 files changed, 4 insertions(+), 4 deletions(-)
+
+--- a/arch/mips/crypto/Makefile
++++ b/arch/mips/crypto/Makefile
+@@ -12,8 +12,8 @@ AFLAGS_chacha-core.o += -O2 # needed to
+ obj-$(CONFIG_CRYPTO_POLY1305_MIPS) += poly1305-mips.o
+ poly1305-mips-y := poly1305-core.o poly1305-glue.o
+ 
+-perlasm-flavour-$(CONFIG_CPU_MIPS32) := o32
+-perlasm-flavour-$(CONFIG_CPU_MIPS64) := 64
++perlasm-flavour-$(CONFIG_32BIT) := o32
++perlasm-flavour-$(CONFIG_64BIT) := 64
+ 
+ quiet_cmd_perlasm = PERLASM $@
+       cmd_perlasm = $(PERL) $(<) $(perlasm-flavour-y) $(@)
+--- a/crypto/Kconfig
++++ b/crypto/Kconfig
+@@ -740,7 +740,7 @@ config CRYPTO_POLY1305_X86_64
+ 
+ config CRYPTO_POLY1305_MIPS
+ 	tristate "Poly1305 authenticator algorithm (MIPS optimized)"
+-	depends on CPU_MIPS32 || (CPU_MIPS64 && 64BIT)
++	depends on MIPS
+ 	select CRYPTO_ARCH_HAVE_LIB_POLY1305
+ 
+ config CRYPTO_MD4
+--- a/drivers/net/Kconfig
++++ b/drivers/net/Kconfig
+@@ -92,7 +92,7 @@ config WIREGUARD
+ 	select CRYPTO_POLY1305_ARM if ARM
+ 	select CRYPTO_CURVE25519_NEON if ARM && KERNEL_MODE_NEON
+ 	select CRYPTO_CHACHA_MIPS if CPU_MIPS32_R2
+-	select CRYPTO_POLY1305_MIPS if CPU_MIPS32 || (CPU_MIPS64 && 64BIT)
++	select CRYPTO_POLY1305_MIPS if MIPS
+ 	help
+ 	  WireGuard is a secure, fast, and easy to use replacement for IPSec
+ 	  that uses modern cryptography and clever networking tricks. It's
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0125-crypto-mips-add-poly1305-core.S-to-.gitignore.patch b/target/linux/generic/backport-5.4/080-wireguard-0125-crypto-mips-add-poly1305-core.S-to-.gitignore.patch
new file mode 100644
index 0000000000..856d67d5b8
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0125-crypto-mips-add-poly1305-core.S-to-.gitignore.patch
@@ -0,0 +1,24 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
+Date: Sat, 27 Mar 2021 19:39:43 -0700
+Subject: [PATCH] crypto: mips: add poly1305-core.S to .gitignore
+
+commit dc92d0df51dc61de88bf6f4884a17bf73d5c6326 upstream.
+
+poly1305-core.S is an auto-generated file, so it should be ignored.
+
+Fixes: a11d055e7a64 ("crypto: mips/poly1305 - incorporate OpenSSL/CRYPTOGAMS optimized implementation")
+Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
+Cc: Ard Biesheuvel <ardb@kernel.org>
+Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ arch/mips/crypto/.gitignore | 2 ++
+ 1 file changed, 2 insertions(+)
+ create mode 100644 arch/mips/crypto/.gitignore
+
+--- /dev/null
++++ b/arch/mips/crypto/.gitignore
+@@ -0,0 +1,2 @@
++# SPDX-License-Identifier: GPL-2.0-only
++poly1305-core.S
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0126-crypto-poly1305-fix-poly1305_core_setkey-declaration.patch b/target/linux/generic/backport-5.4/080-wireguard-0126-crypto-poly1305-fix-poly1305_core_setkey-declaration.patch
new file mode 100644
index 0000000000..ded6625aeb
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0126-crypto-poly1305-fix-poly1305_core_setkey-declaration.patch
@@ -0,0 +1,172 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Arnd Bergmann <arnd@arndb.de>
+Date: Mon, 22 Mar 2021 18:05:15 +0100
+Subject: [PATCH] crypto: poly1305 - fix poly1305_core_setkey() declaration
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+commit 8d195e7a8ada68928f2aedb2c18302a4518fe68e upstream.
+
+gcc-11 points out a mismatch between the declaration and the definition
+of poly1305_core_setkey():
+
+lib/crypto/poly1305-donna32.c:13:67: error: argument 2 of type ‘const u8[16]’ {aka ‘const unsigned char[16]’} with mismatched bound [-Werror=array-parameter=]
+   13 | void poly1305_core_setkey(struct poly1305_core_key *key, const u8 raw_key[16])
+      |                                                          ~~~~~~~~~^~~~~~~~~~~
+In file included from lib/crypto/poly1305-donna32.c:11:
+include/crypto/internal/poly1305.h:21:68: note: previously declared as ‘const u8 *’ {aka ‘const unsigned char *’}
+   21 | void poly1305_core_setkey(struct poly1305_core_key *key, const u8 *raw_key);
+
+This is harmless in principle, as the calling conventions are the same,
+but the more specific prototype allows better type checking in the
+caller.
+
+Change the declaration to match the actual function definition.
+The poly1305_simd_init() is a bit suspicious here, as it previously
+had a 32-byte argument type, but looks like it needs to take the
+16-byte POLY1305_BLOCK_SIZE array instead.
+
+Fixes: 1c08a104360f ("crypto: poly1305 - add new 32 and 64-bit generic versions")
+Signed-off-by: Arnd Bergmann <arnd@arndb.de>
+Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
+Reviewed-by: Eric Biggers <ebiggers@google.com>
+Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ arch/arm/crypto/poly1305-glue.c    | 2 +-
+ arch/arm64/crypto/poly1305-glue.c  | 2 +-
+ arch/mips/crypto/poly1305-glue.c   | 2 +-
+ arch/x86/crypto/poly1305_glue.c    | 6 +++---
+ include/crypto/internal/poly1305.h | 3 ++-
+ include/crypto/poly1305.h          | 6 ++++--
+ lib/crypto/poly1305-donna32.c      | 3 ++-
+ lib/crypto/poly1305-donna64.c      | 3 ++-
+ lib/crypto/poly1305.c              | 3 ++-
+ 9 files changed, 18 insertions(+), 12 deletions(-)
+
+--- a/arch/arm/crypto/poly1305-glue.c
++++ b/arch/arm/crypto/poly1305-glue.c
+@@ -29,7 +29,7 @@ void __weak poly1305_blocks_neon(void *s
+ 
+ static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
+ 
+-void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
++void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
+ {
+ 	poly1305_init_arm(&dctx->h, key);
+ 	dctx->s[0] = get_unaligned_le32(key + 16);
+--- a/arch/arm64/crypto/poly1305-glue.c
++++ b/arch/arm64/crypto/poly1305-glue.c
+@@ -25,7 +25,7 @@ asmlinkage void poly1305_emit(void *stat
+ 
+ static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
+ 
+-void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
++void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
+ {
+ 	poly1305_init_arm64(&dctx->h, key);
+ 	dctx->s[0] = get_unaligned_le32(key + 16);
+--- a/arch/mips/crypto/poly1305-glue.c
++++ b/arch/mips/crypto/poly1305-glue.c
+@@ -17,7 +17,7 @@ asmlinkage void poly1305_init_mips(void
+ asmlinkage void poly1305_blocks_mips(void *state, const u8 *src, u32 len, u32 hibit);
+ asmlinkage void poly1305_emit_mips(void *state, u8 *digest, const u32 *nonce);
+ 
+-void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
++void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
+ {
+ 	poly1305_init_mips(&dctx->h, key);
+ 	dctx->s[0] = get_unaligned_le32(key + 16);
+--- a/arch/x86/crypto/poly1305_glue.c
++++ b/arch/x86/crypto/poly1305_glue.c
+@@ -15,7 +15,7 @@
+ #include <asm/simd.h>
+ 
+ asmlinkage void poly1305_init_x86_64(void *ctx,
+-				     const u8 key[POLY1305_KEY_SIZE]);
++				     const u8 key[POLY1305_BLOCK_SIZE]);
+ asmlinkage void poly1305_blocks_x86_64(void *ctx, const u8 *inp,
+ 				       const size_t len, const u32 padbit);
+ asmlinkage void poly1305_emit_x86_64(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
+@@ -80,7 +80,7 @@ static void convert_to_base2_64(void *ct
+ 	state->is_base2_26 = 0;
+ }
+ 
+-static void poly1305_simd_init(void *ctx, const u8 key[POLY1305_KEY_SIZE])
++static void poly1305_simd_init(void *ctx, const u8 key[POLY1305_BLOCK_SIZE])
+ {
+ 	poly1305_init_x86_64(ctx, key);
+ }
+@@ -128,7 +128,7 @@ static void poly1305_simd_emit(void *ctx
+ 		poly1305_emit_avx(ctx, mac, nonce);
+ }
+ 
+-void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
++void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
+ {
+ 	poly1305_simd_init(&dctx->h, key);
+ 	dctx->s[0] = get_unaligned_le32(&key[16]);
+--- a/include/crypto/internal/poly1305.h
++++ b/include/crypto/internal/poly1305.h
+@@ -18,7 +18,8 @@
+  * only the ε-almost-∆-universal hash function (not the full MAC) is computed.
+  */
+ 
+-void poly1305_core_setkey(struct poly1305_core_key *key, const u8 *raw_key);
++void poly1305_core_setkey(struct poly1305_core_key *key,
++			  const u8 raw_key[POLY1305_BLOCK_SIZE]);
+ static inline void poly1305_core_init(struct poly1305_state *state)
+ {
+ 	*state = (struct poly1305_state){};
+--- a/include/crypto/poly1305.h
++++ b/include/crypto/poly1305.h
+@@ -58,8 +58,10 @@ struct poly1305_desc_ctx {
+ 	};
+ };
+ 
+-void poly1305_init_arch(struct poly1305_desc_ctx *desc, const u8 *key);
+-void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key);
++void poly1305_init_arch(struct poly1305_desc_ctx *desc,
++			const u8 key[POLY1305_KEY_SIZE]);
++void poly1305_init_generic(struct poly1305_desc_ctx *desc,
++			   const u8 key[POLY1305_KEY_SIZE]);
+ 
+ static inline void poly1305_init(struct poly1305_desc_ctx *desc, const u8 *key)
+ {
+--- a/lib/crypto/poly1305-donna32.c
++++ b/lib/crypto/poly1305-donna32.c
+@@ -10,7 +10,8 @@
+ #include <asm/unaligned.h>
+ #include <crypto/internal/poly1305.h>
+ 
+-void poly1305_core_setkey(struct poly1305_core_key *key, const u8 raw_key[16])
++void poly1305_core_setkey(struct poly1305_core_key *key,
++			  const u8 raw_key[POLY1305_BLOCK_SIZE])
+ {
+ 	/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
+ 	key->key.r[0] = (get_unaligned_le32(&raw_key[0])) & 0x3ffffff;
+--- a/lib/crypto/poly1305-donna64.c
++++ b/lib/crypto/poly1305-donna64.c
+@@ -12,7 +12,8 @@
+ 
+ typedef __uint128_t u128;
+ 
+-void poly1305_core_setkey(struct poly1305_core_key *key, const u8 raw_key[16])
++void poly1305_core_setkey(struct poly1305_core_key *key,
++			  const u8 raw_key[POLY1305_BLOCK_SIZE])
+ {
+ 	u64 t0, t1;
+ 
+--- a/lib/crypto/poly1305.c
++++ b/lib/crypto/poly1305.c
+@@ -12,7 +12,8 @@
+ #include <linux/module.h>
+ #include <asm/unaligned.h>
+ 
+-void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key)
++void poly1305_init_generic(struct poly1305_desc_ctx *desc,
++			   const u8 key[POLY1305_KEY_SIZE])
+ {
+ 	poly1305_core_setkey(&desc->core_r, key);
+ 	desc->s[0] = get_unaligned_le32(key + 16);
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0127-wireguard-selftests-remove-old-conntrack-kconfig-val.patch b/target/linux/generic/backport-5.4/080-wireguard-0127-wireguard-selftests-remove-old-conntrack-kconfig-val.patch
new file mode 100644
index 0000000000..3e7d1a8e02
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0127-wireguard-selftests-remove-old-conntrack-kconfig-val.patch
@@ -0,0 +1,29 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:30 +0200
+Subject: [PATCH] wireguard: selftests: remove old conntrack kconfig value
+
+commit acf2492b51c9a3c4dfb947f4d3477a86d315150f upstream.
+
+On recent kernels, this config symbol is no longer used.
+
+Reported-by: Rui Salvaterra <rsalvaterra@gmail.com>
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ tools/testing/selftests/wireguard/qemu/kernel.config | 1 -
+ 1 file changed, 1 deletion(-)
+
+--- a/tools/testing/selftests/wireguard/qemu/kernel.config
++++ b/tools/testing/selftests/wireguard/qemu/kernel.config
+@@ -19,7 +19,6 @@ CONFIG_NETFILTER_XTABLES=y
+ CONFIG_NETFILTER_XT_NAT=y
+ CONFIG_NETFILTER_XT_MATCH_LENGTH=y
+ CONFIG_NETFILTER_XT_MARK=y
+-CONFIG_NF_CONNTRACK_IPV4=y
+ CONFIG_NF_NAT_IPV4=y
+ CONFIG_IP_NF_IPTABLES=y
+ CONFIG_IP_NF_FILTER=y
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0128-wireguard-selftests-make-sure-rp_filter-is-disabled-.patch b/target/linux/generic/backport-5.4/080-wireguard-0128-wireguard-selftests-make-sure-rp_filter-is-disabled-.patch
new file mode 100644
index 0000000000..22d0f3e32e
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0128-wireguard-selftests-make-sure-rp_filter-is-disabled-.patch
@@ -0,0 +1,31 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:31 +0200
+Subject: [PATCH] wireguard: selftests: make sure rp_filter is disabled on
+ vethc
+
+commit f8873d11d4121aad35024f9379e431e0c83abead upstream.
+
+Some distros may enable strict rp_filter by default, which will prevent
+vethc from receiving the packets with an unrouteable reverse path address.
+
+Reported-by: Hangbin Liu <liuhangbin@gmail.com>
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ tools/testing/selftests/wireguard/netns.sh | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/tools/testing/selftests/wireguard/netns.sh
++++ b/tools/testing/selftests/wireguard/netns.sh
+@@ -363,6 +363,7 @@ ip1 -6 rule add table main suppress_pref
+ ip1 -4 route add default dev wg0 table 51820
+ ip1 -4 rule add not fwmark 51820 table 51820
+ ip1 -4 rule add table main suppress_prefixlength 0
++n1 bash -c 'printf 0 > /proc/sys/net/ipv4/conf/vethc/rp_filter'
+ # Flood the pings instead of sending just one, to trigger routing table reference counting bugs.
+ n1 ping -W 1 -c 100 -f 192.168.99.7
+ n1 ping -W 1 -c 100 -f abab::1111
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0129-wireguard-do-not-use-O3.patch b/target/linux/generic/backport-5.4/080-wireguard-0129-wireguard-do-not-use-O3.patch
new file mode 100644
index 0000000000..a7890a7384
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0129-wireguard-do-not-use-O3.patch
@@ -0,0 +1,33 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:32 +0200
+Subject: [PATCH] wireguard: do not use -O3
+
+commit cc5060ca0285efe2728bced399a1955a7ce808b2 upstream.
+
+Apparently, various versions of gcc have O3-related miscompiles. Looking
+at the difference between -O2 and -O3 for gcc 11 doesn't indicate
+miscompiles, but the difference also doesn't seem so significant for
+performance that it's worth risking.
+
+Link: https://lore.kernel.org/lkml/CAHk-=wjuoGyxDhAF8SsrTkN0-YfCx7E6jUN3ikC_tn2AKWTTsA@mail.gmail.com/
+Link: https://lore.kernel.org/lkml/CAHmME9otB5Wwxp7H8bR_i2uH2esEMvoBMC8uEXBMH9p0q1s6Bw@mail.gmail.com/
+Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/Makefile | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/drivers/net/wireguard/Makefile
++++ b/drivers/net/wireguard/Makefile
+@@ -1,5 +1,4 @@
+-ccflags-y := -O3
+-ccflags-y += -D'pr_fmt(fmt)=KBUILD_MODNAME ": " fmt'
++ccflags-y := -D'pr_fmt(fmt)=KBUILD_MODNAME ": " fmt'
+ ccflags-$(CONFIG_WIREGUARD_DEBUG) += -DDEBUG
+ wireguard-y := main.o
+ wireguard-y += noise.o
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0130-wireguard-use-synchronize_net-rather-than-synchroniz.patch b/target/linux/generic/backport-5.4/080-wireguard-0130-wireguard-use-synchronize_net-rather-than-synchroniz.patch
new file mode 100644
index 0000000000..309fe36198
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0130-wireguard-use-synchronize_net-rather-than-synchroniz.patch
@@ -0,0 +1,66 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:33 +0200
+Subject: [PATCH] wireguard: use synchronize_net rather than synchronize_rcu
+
+commit 24b70eeeb4f46c09487f8155239ebfb1f875774a upstream.
+
+Many of the synchronization points are sometimes called under the rtnl
+lock, which means we should use synchronize_net rather than
+synchronize_rcu. Under the hood, this expands to using the expedited
+flavor of function in the event that rtnl is held, in order to not stall
+other concurrent changes.
+
+This fixes some very, very long delays when removing multiple peers at
+once, which would cause some operations to take several minutes.
+
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/peer.c   | 6 +++---
+ drivers/net/wireguard/socket.c | 2 +-
+ 2 files changed, 4 insertions(+), 4 deletions(-)
+
+--- a/drivers/net/wireguard/peer.c
++++ b/drivers/net/wireguard/peer.c
+@@ -88,7 +88,7 @@ static void peer_make_dead(struct wg_pee
+ 	/* Mark as dead, so that we don't allow jumping contexts after. */
+ 	WRITE_ONCE(peer->is_dead, true);
+ 
+-	/* The caller must now synchronize_rcu() for this to take effect. */
++	/* The caller must now synchronize_net() for this to take effect. */
+ }
+ 
+ static void peer_remove_after_dead(struct wg_peer *peer)
+@@ -160,7 +160,7 @@ void wg_peer_remove(struct wg_peer *peer
+ 	lockdep_assert_held(&peer->device->device_update_lock);
+ 
+ 	peer_make_dead(peer);
+-	synchronize_rcu();
++	synchronize_net();
+ 	peer_remove_after_dead(peer);
+ }
+ 
+@@ -178,7 +178,7 @@ void wg_peer_remove_all(struct wg_device
+ 		peer_make_dead(peer);
+ 		list_add_tail(&peer->peer_list, &dead_peers);
+ 	}
+-	synchronize_rcu();
++	synchronize_net();
+ 	list_for_each_entry_safe(peer, temp, &dead_peers, peer_list)
+ 		peer_remove_after_dead(peer);
+ }
+--- a/drivers/net/wireguard/socket.c
++++ b/drivers/net/wireguard/socket.c
+@@ -430,7 +430,7 @@ void wg_socket_reinit(struct wg_device *
+ 	if (new4)
+ 		wg->incoming_port = ntohs(inet_sk(new4)->inet_sport);
+ 	mutex_unlock(&wg->socket_update_lock);
+-	synchronize_rcu();
++	synchronize_net();
+ 	sock_free(old4);
+ 	sock_free(old6);
+ }
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0131-wireguard-peer-allocate-in-kmem_cache.patch b/target/linux/generic/backport-5.4/080-wireguard-0131-wireguard-peer-allocate-in-kmem_cache.patch
new file mode 100644
index 0000000000..32ae327037
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0131-wireguard-peer-allocate-in-kmem_cache.patch
@@ -0,0 +1,125 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:34 +0200
+Subject: [PATCH] wireguard: peer: allocate in kmem_cache
+
+commit a4e9f8e3287c9eb6bf70df982870980dd3341863 upstream.
+
+With deployments having upwards of 600k peers now, this somewhat heavy
+structure could benefit from more fine-grained allocations.
+Specifically, instead of using a 2048-byte slab for a 1544-byte object,
+we can now use 1544-byte objects directly, thus saving almost 25%
+per-peer, or with 600k peers, that's a savings of 303 MiB. This also
+makes wireguard's memory usage more transparent in tools like slabtop
+and /proc/slabinfo.
+
+Fixes: 8b5553ace83c ("wireguard: queueing: get rid of per-peer ring buffers")
+Suggested-by: Arnd Bergmann <arnd@arndb.de>
+Suggested-by: Matthew Wilcox <willy@infradead.org>
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/main.c |  7 +++++++
+ drivers/net/wireguard/peer.c | 21 +++++++++++++++++----
+ drivers/net/wireguard/peer.h |  3 +++
+ 3 files changed, 27 insertions(+), 4 deletions(-)
+
+--- a/drivers/net/wireguard/main.c
++++ b/drivers/net/wireguard/main.c
+@@ -28,6 +28,10 @@ static int __init mod_init(void)
+ #endif
+ 	wg_noise_init();
+ 
++	ret = wg_peer_init();
++	if (ret < 0)
++		goto err_peer;
++
+ 	ret = wg_device_init();
+ 	if (ret < 0)
+ 		goto err_device;
+@@ -44,6 +48,8 @@ static int __init mod_init(void)
+ err_netlink:
+ 	wg_device_uninit();
+ err_device:
++	wg_peer_uninit();
++err_peer:
+ 	return ret;
+ }
+ 
+@@ -51,6 +57,7 @@ static void __exit mod_exit(void)
+ {
+ 	wg_genetlink_uninit();
+ 	wg_device_uninit();
++	wg_peer_uninit();
+ }
+ 
+ module_init(mod_init);
+--- a/drivers/net/wireguard/peer.c
++++ b/drivers/net/wireguard/peer.c
+@@ -15,6 +15,7 @@
+ #include <linux/rcupdate.h>
+ #include <linux/list.h>
+ 
++static struct kmem_cache *peer_cache;
+ static atomic64_t peer_counter = ATOMIC64_INIT(0);
+ 
+ struct wg_peer *wg_peer_create(struct wg_device *wg,
+@@ -29,10 +30,10 @@ struct wg_peer *wg_peer_create(struct wg
+ 	if (wg->num_peers >= MAX_PEERS_PER_DEVICE)
+ 		return ERR_PTR(ret);
+ 
+-	peer = kzalloc(sizeof(*peer), GFP_KERNEL);
++	peer = kmem_cache_zalloc(peer_cache, GFP_KERNEL);
+ 	if (unlikely(!peer))
+ 		return ERR_PTR(ret);
+-	if (dst_cache_init(&peer->endpoint_cache, GFP_KERNEL))
++	if (unlikely(dst_cache_init(&peer->endpoint_cache, GFP_KERNEL)))
+ 		goto err;
+ 
+ 	peer->device = wg;
+@@ -64,7 +65,7 @@ struct wg_peer *wg_peer_create(struct wg
+ 	return peer;
+ 
+ err:
+-	kfree(peer);
++	kmem_cache_free(peer_cache, peer);
+ 	return ERR_PTR(ret);
+ }
+ 
+@@ -193,7 +194,8 @@ static void rcu_release(struct rcu_head
+ 	/* The final zeroing takes care of clearing any remaining handshake key
+ 	 * material and other potentially sensitive information.
+ 	 */
+-	kzfree(peer);
++	memzero_explicit(peer, sizeof(*peer));
++	kmem_cache_free(peer_cache, peer);
+ }
+ 
+ static void kref_release(struct kref *refcount)
+@@ -225,3 +227,14 @@ void wg_peer_put(struct wg_peer *peer)
+ 		return;
+ 	kref_put(&peer->refcount, kref_release);
+ }
++
++int __init wg_peer_init(void)
++{
++	peer_cache = KMEM_CACHE(wg_peer, 0);
++	return peer_cache ? 0 : -ENOMEM;
++}
++
++void wg_peer_uninit(void)
++{
++	kmem_cache_destroy(peer_cache);
++}
+--- a/drivers/net/wireguard/peer.h
++++ b/drivers/net/wireguard/peer.h
+@@ -80,4 +80,7 @@ void wg_peer_put(struct wg_peer *peer);
+ void wg_peer_remove(struct wg_peer *peer);
+ void wg_peer_remove_all(struct wg_device *wg);
+ 
++int wg_peer_init(void);
++void wg_peer_uninit(void);
++
+ #endif /* _WG_PEER_H */
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0132-wireguard-allowedips-initialize-list-head-in-selftes.patch b/target/linux/generic/backport-5.4/080-wireguard-0132-wireguard-allowedips-initialize-list-head-in-selftes.patch
new file mode 100644
index 0000000000..ce4e5dcf50
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0132-wireguard-allowedips-initialize-list-head-in-selftes.patch
@@ -0,0 +1,43 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:35 +0200
+Subject: [PATCH] wireguard: allowedips: initialize list head in selftest
+
+commit 46cfe8eee285cde465b420637507884551f5d7ca upstream.
+
+The randomized trie tests weren't initializing the dummy peer list head,
+resulting in a NULL pointer dereference when used. Fix this by
+initializing it in the randomized trie test, just like we do for the
+static unit test.
+
+While we're at it, all of the other strings like this have the word
+"self-test", so add it to the missing place here.
+
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/selftest/allowedips.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/drivers/net/wireguard/selftest/allowedips.c
++++ b/drivers/net/wireguard/selftest/allowedips.c
+@@ -296,6 +296,7 @@ static __init bool randomized_test(void)
+ 			goto free;
+ 		}
+ 		kref_init(&peers[i]->refcount);
++		INIT_LIST_HEAD(&peers[i]->allowedips_list);
+ 	}
+ 
+ 	mutex_lock(&mutex);
+@@ -333,7 +334,7 @@ static __init bool randomized_test(void)
+ 			if (wg_allowedips_insert_v4(&t,
+ 						    (struct in_addr *)mutated,
+ 						    cidr, peer, &mutex) < 0) {
+-				pr_err("allowedips random malloc: FAIL\n");
++				pr_err("allowedips random self-test malloc: FAIL\n");
+ 				goto free_locked;
+ 			}
+ 			if (horrible_allowedips_insert_v4(&h,
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0133-wireguard-allowedips-remove-nodes-in-O-1.patch b/target/linux/generic/backport-5.4/080-wireguard-0133-wireguard-allowedips-remove-nodes-in-O-1.patch
new file mode 100644
index 0000000000..78da24ea46
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0133-wireguard-allowedips-remove-nodes-in-O-1.patch
@@ -0,0 +1,237 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:36 +0200
+Subject: [PATCH] wireguard: allowedips: remove nodes in O(1)
+
+commit f634f418c227c912e7ea95a3299efdc9b10e4022 upstream.
+
+Previously, deleting peers would require traversing the entire trie in
+order to rebalance nodes and safely free them. This meant that removing
+1000 peers from a trie with a half million nodes would take an extremely
+long time, during which we're holding the rtnl lock. Large-scale users
+were reporting 200ms latencies added to the networking stack as a whole
+every time their userspace software would queue up significant removals.
+That's a serious situation.
+
+This commit fixes that by maintaining a double pointer to the parent's
+bit pointer for each node, and then using the already existing node list
+belonging to each peer to go directly to the node, fix up its pointers,
+and free it with RCU. This means removal is O(1) instead of O(n), and we
+don't use gobs of stack.
+
+The removal algorithm has the same downside as the code that it fixes:
+it won't collapse needlessly long runs of fillers.  We can enhance that
+in the future if it ever becomes a problem. This commit documents that
+limitation with a TODO comment in code, a small but meaningful
+improvement over the prior situation.
+
+Currently the biggest flaw, which the next commit addresses, is that
+because this increases the node size on 64-bit machines from 60 bytes to
+68 bytes. 60 rounds up to 64, but 68 rounds up to 128. So we wind up
+using twice as much memory per node, because of power-of-two
+allocations, which is a big bummer. We'll need to figure something out
+there.
+
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/allowedips.c | 132 ++++++++++++-----------------
+ drivers/net/wireguard/allowedips.h |   9 +-
+ 2 files changed, 57 insertions(+), 84 deletions(-)
+
+--- a/drivers/net/wireguard/allowedips.c
++++ b/drivers/net/wireguard/allowedips.c
+@@ -66,60 +66,6 @@ static void root_remove_peer_lists(struc
+ 	}
+ }
+ 
+-static void walk_remove_by_peer(struct allowedips_node __rcu **top,
+-				struct wg_peer *peer, struct mutex *lock)
+-{
+-#define REF(p) rcu_access_pointer(p)
+-#define DEREF(p) rcu_dereference_protected(*(p), lockdep_is_held(lock))
+-#define PUSH(p) ({                                                             \
+-		WARN_ON(IS_ENABLED(DEBUG) && len >= 128);                      \
+-		stack[len++] = p;                                              \
+-	})
+-
+-	struct allowedips_node __rcu **stack[128], **nptr;
+-	struct allowedips_node *node, *prev;
+-	unsigned int len;
+-
+-	if (unlikely(!peer || !REF(*top)))
+-		return;
+-
+-	for (prev = NULL, len = 0, PUSH(top); len > 0; prev = node) {
+-		nptr = stack[len - 1];
+-		node = DEREF(nptr);
+-		if (!node) {
+-			--len;
+-			continue;
+-		}
+-		if (!prev || REF(prev->bit[0]) == node ||
+-		    REF(prev->bit[1]) == node) {
+-			if (REF(node->bit[0]))
+-				PUSH(&node->bit[0]);
+-			else if (REF(node->bit[1]))
+-				PUSH(&node->bit[1]);
+-		} else if (REF(node->bit[0]) == prev) {
+-			if (REF(node->bit[1]))
+-				PUSH(&node->bit[1]);
+-		} else {
+-			if (rcu_dereference_protected(node->peer,
+-				lockdep_is_held(lock)) == peer) {
+-				RCU_INIT_POINTER(node->peer, NULL);
+-				list_del_init(&node->peer_list);
+-				if (!node->bit[0] || !node->bit[1]) {
+-					rcu_assign_pointer(*nptr, DEREF(
+-					       &node->bit[!REF(node->bit[0])]));
+-					kfree_rcu(node, rcu);
+-					node = DEREF(nptr);
+-				}
+-			}
+-			--len;
+-		}
+-	}
+-
+-#undef REF
+-#undef DEREF
+-#undef PUSH
+-}
+-
+ static unsigned int fls128(u64 a, u64 b)
+ {
+ 	return a ? fls64(a) + 64U : fls64(b);
+@@ -224,6 +170,7 @@ static int add(struct allowedips_node __
+ 		RCU_INIT_POINTER(node->peer, peer);
+ 		list_add_tail(&node->peer_list, &peer->allowedips_list);
+ 		copy_and_assign_cidr(node, key, cidr, bits);
++		rcu_assign_pointer(node->parent_bit, trie);
+ 		rcu_assign_pointer(*trie, node);
+ 		return 0;
+ 	}
+@@ -243,9 +190,9 @@ static int add(struct allowedips_node __
+ 	if (!node) {
+ 		down = rcu_dereference_protected(*trie, lockdep_is_held(lock));
+ 	} else {
+-		down = rcu_dereference_protected(CHOOSE_NODE(node, key),
+-						 lockdep_is_held(lock));
++		down = rcu_dereference_protected(CHOOSE_NODE(node, key), lockdep_is_held(lock));
+ 		if (!down) {
++			rcu_assign_pointer(newnode->parent_bit, &CHOOSE_NODE(node, key));
+ 			rcu_assign_pointer(CHOOSE_NODE(node, key), newnode);
+ 			return 0;
+ 		}
+@@ -254,29 +201,37 @@ static int add(struct allowedips_node __
+ 	parent = node;
+ 
+ 	if (newnode->cidr == cidr) {
++		rcu_assign_pointer(down->parent_bit, &CHOOSE_NODE(newnode, down->bits));
+ 		rcu_assign_pointer(CHOOSE_NODE(newnode, down->bits), down);
+-		if (!parent)
++		if (!parent) {
++			rcu_assign_pointer(newnode->parent_bit, trie);
+ 			rcu_assign_pointer(*trie, newnode);
+-		else
+-			rcu_assign_pointer(CHOOSE_NODE(parent, newnode->bits),
+-					   newnode);
+-	} else {
+-		node = kzalloc(sizeof(*node), GFP_KERNEL);
+-		if (unlikely(!node)) {
+-			list_del(&newnode->peer_list);
+-			kfree(newnode);
+-			return -ENOMEM;
++		} else {
++			rcu_assign_pointer(newnode->parent_bit, &CHOOSE_NODE(parent, newnode->bits));
++			rcu_assign_pointer(CHOOSE_NODE(parent, newnode->bits), newnode);
+ 		}
+-		INIT_LIST_HEAD(&node->peer_list);
+-		copy_and_assign_cidr(node, newnode->bits, cidr, bits);
++		return 0;
++	}
++
++	node = kzalloc(sizeof(*node), GFP_KERNEL);
++	if (unlikely(!node)) {
++		list_del(&newnode->peer_list);
++		kfree(newnode);
++		return -ENOMEM;
++	}
++	INIT_LIST_HEAD(&node->peer_list);
++	copy_and_assign_cidr(node, newnode->bits, cidr, bits);
+ 
+-		rcu_assign_pointer(CHOOSE_NODE(node, down->bits), down);
+-		rcu_assign_pointer(CHOOSE_NODE(node, newnode->bits), newnode);
+-		if (!parent)
+-			rcu_assign_pointer(*trie, node);
+-		else
+-			rcu_assign_pointer(CHOOSE_NODE(parent, node->bits),
+-					   node);
++	rcu_assign_pointer(down->parent_bit, &CHOOSE_NODE(node, down->bits));
++	rcu_assign_pointer(CHOOSE_NODE(node, down->bits), down);
++	rcu_assign_pointer(newnode->parent_bit, &CHOOSE_NODE(node, newnode->bits));
++	rcu_assign_pointer(CHOOSE_NODE(node, newnode->bits), newnode);
++	if (!parent) {
++		rcu_assign_pointer(node->parent_bit, trie);
++		rcu_assign_pointer(*trie, node);
++	} else {
++		rcu_assign_pointer(node->parent_bit, &CHOOSE_NODE(parent, node->bits));
++		rcu_assign_pointer(CHOOSE_NODE(parent, node->bits), node);
+ 	}
+ 	return 0;
+ }
+@@ -335,9 +290,30 @@ int wg_allowedips_insert_v6(struct allow
+ void wg_allowedips_remove_by_peer(struct allowedips *table,
+ 				  struct wg_peer *peer, struct mutex *lock)
+ {
++	struct allowedips_node *node, *child, *tmp;
++
++	if (list_empty(&peer->allowedips_list))
++		return;
+ 	++table->seq;
+-	walk_remove_by_peer(&table->root4, peer, lock);
+-	walk_remove_by_peer(&table->root6, peer, lock);
++	list_for_each_entry_safe(node, tmp, &peer->allowedips_list, peer_list) {
++		list_del_init(&node->peer_list);
++		RCU_INIT_POINTER(node->peer, NULL);
++		if (node->bit[0] && node->bit[1])
++			continue;
++		child = rcu_dereference_protected(
++				node->bit[!rcu_access_pointer(node->bit[0])],
++				lockdep_is_held(lock));
++		if (child)
++			child->parent_bit = node->parent_bit;
++		*rcu_dereference_protected(node->parent_bit, lockdep_is_held(lock)) = child;
++		kfree_rcu(node, rcu);
++
++		/* TODO: Note that we currently don't walk up and down in order to
++		 * free any potential filler nodes. This means that this function
++		 * doesn't free up as much as it could, which could be revisited
++		 * at some point.
++		 */
++	}
+ }
+ 
+ int wg_allowedips_read_node(struct allowedips_node *node, u8 ip[16], u8 *cidr)
+--- a/drivers/net/wireguard/allowedips.h
++++ b/drivers/net/wireguard/allowedips.h
+@@ -15,14 +15,11 @@ struct wg_peer;
+ struct allowedips_node {
+ 	struct wg_peer __rcu *peer;
+ 	struct allowedips_node __rcu *bit[2];
+-	/* While it may seem scandalous that we waste space for v4,
+-	 * we're alloc'ing to the nearest power of 2 anyway, so this
+-	 * doesn't actually make a difference.
+-	 */
+-	u8 bits[16] __aligned(__alignof(u64));
+ 	u8 cidr, bit_at_a, bit_at_b, bitlen;
++	u8 bits[16] __aligned(__alignof(u64));
+ 
+-	/* Keep rarely used list at bottom to be beyond cache line. */
++	/* Keep rarely used members at bottom to be beyond cache line. */
++	struct allowedips_node *__rcu *parent_bit; /* XXX: this puts us at 68->128 bytes instead of 60->64 bytes!! */
+ 	union {
+ 		struct list_head peer_list;
+ 		struct rcu_head rcu;
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0134-wireguard-allowedips-allocate-nodes-in-kmem_cache.patch b/target/linux/generic/backport-5.4/080-wireguard-0134-wireguard-allowedips-allocate-nodes-in-kmem_cache.patch
new file mode 100644
index 0000000000..65b31b05f5
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0134-wireguard-allowedips-allocate-nodes-in-kmem_cache.patch
@@ -0,0 +1,173 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:37 +0200
+Subject: [PATCH] wireguard: allowedips: allocate nodes in kmem_cache
+
+commit dc680de28ca849dfe589dc15ac56d22505f0ef11 upstream.
+
+The previous commit moved from O(n) to O(1) for removal, but in the
+process introduced an additional pointer member to a struct that
+increased the size from 60 to 68 bytes, putting nodes in the 128-byte
+slab. With deployed systems having as many as 2 million nodes, this
+represents a significant doubling in memory usage (128 MiB -> 256 MiB).
+Fix this by using our own kmem_cache, that's sized exactly right. This
+also makes wireguard's memory usage more transparent in tools like
+slabtop and /proc/slabinfo.
+
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Suggested-by: Arnd Bergmann <arnd@arndb.de>
+Suggested-by: Matthew Wilcox <willy@infradead.org>
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/allowedips.c | 31 ++++++++++++++++++++++++------
+ drivers/net/wireguard/allowedips.h |  5 ++++-
+ drivers/net/wireguard/main.c       | 10 +++++++++-
+ 3 files changed, 38 insertions(+), 8 deletions(-)
+
+--- a/drivers/net/wireguard/allowedips.c
++++ b/drivers/net/wireguard/allowedips.c
+@@ -6,6 +6,8 @@
+ #include "allowedips.h"
+ #include "peer.h"
+ 
++static struct kmem_cache *node_cache;
++
+ static void swap_endian(u8 *dst, const u8 *src, u8 bits)
+ {
+ 	if (bits == 32) {
+@@ -40,6 +42,11 @@ static void push_rcu(struct allowedips_n
+ 	}
+ }
+ 
++static void node_free_rcu(struct rcu_head *rcu)
++{
++	kmem_cache_free(node_cache, container_of(rcu, struct allowedips_node, rcu));
++}
++
+ static void root_free_rcu(struct rcu_head *rcu)
+ {
+ 	struct allowedips_node *node, *stack[128] = {
+@@ -49,7 +56,7 @@ static void root_free_rcu(struct rcu_hea
+ 	while (len > 0 && (node = stack[--len])) {
+ 		push_rcu(stack, node->bit[0], &len);
+ 		push_rcu(stack, node->bit[1], &len);
+-		kfree(node);
++		kmem_cache_free(node_cache, node);
+ 	}
+ }
+ 
+@@ -164,7 +171,7 @@ static int add(struct allowedips_node __
+ 		return -EINVAL;
+ 
+ 	if (!rcu_access_pointer(*trie)) {
+-		node = kzalloc(sizeof(*node), GFP_KERNEL);
++		node = kmem_cache_zalloc(node_cache, GFP_KERNEL);
+ 		if (unlikely(!node))
+ 			return -ENOMEM;
+ 		RCU_INIT_POINTER(node->peer, peer);
+@@ -180,7 +187,7 @@ static int add(struct allowedips_node __
+ 		return 0;
+ 	}
+ 
+-	newnode = kzalloc(sizeof(*newnode), GFP_KERNEL);
++	newnode = kmem_cache_zalloc(node_cache, GFP_KERNEL);
+ 	if (unlikely(!newnode))
+ 		return -ENOMEM;
+ 	RCU_INIT_POINTER(newnode->peer, peer);
+@@ -213,10 +220,10 @@ static int add(struct allowedips_node __
+ 		return 0;
+ 	}
+ 
+-	node = kzalloc(sizeof(*node), GFP_KERNEL);
++	node = kmem_cache_zalloc(node_cache, GFP_KERNEL);
+ 	if (unlikely(!node)) {
+ 		list_del(&newnode->peer_list);
+-		kfree(newnode);
++		kmem_cache_free(node_cache, newnode);
+ 		return -ENOMEM;
+ 	}
+ 	INIT_LIST_HEAD(&node->peer_list);
+@@ -306,7 +313,7 @@ void wg_allowedips_remove_by_peer(struct
+ 		if (child)
+ 			child->parent_bit = node->parent_bit;
+ 		*rcu_dereference_protected(node->parent_bit, lockdep_is_held(lock)) = child;
+-		kfree_rcu(node, rcu);
++		call_rcu(&node->rcu, node_free_rcu);
+ 
+ 		/* TODO: Note that we currently don't walk up and down in order to
+ 		 * free any potential filler nodes. This means that this function
+@@ -350,4 +357,16 @@ struct wg_peer *wg_allowedips_lookup_src
+ 	return NULL;
+ }
+ 
++int __init wg_allowedips_slab_init(void)
++{
++	node_cache = KMEM_CACHE(allowedips_node, 0);
++	return node_cache ? 0 : -ENOMEM;
++}
++
++void wg_allowedips_slab_uninit(void)
++{
++	rcu_barrier();
++	kmem_cache_destroy(node_cache);
++}
++
+ #include "selftest/allowedips.c"
+--- a/drivers/net/wireguard/allowedips.h
++++ b/drivers/net/wireguard/allowedips.h
+@@ -19,7 +19,7 @@ struct allowedips_node {
+ 	u8 bits[16] __aligned(__alignof(u64));
+ 
+ 	/* Keep rarely used members at bottom to be beyond cache line. */
+-	struct allowedips_node *__rcu *parent_bit; /* XXX: this puts us at 68->128 bytes instead of 60->64 bytes!! */
++	struct allowedips_node *__rcu *parent_bit;
+ 	union {
+ 		struct list_head peer_list;
+ 		struct rcu_head rcu;
+@@ -53,4 +53,7 @@ struct wg_peer *wg_allowedips_lookup_src
+ bool wg_allowedips_selftest(void);
+ #endif
+ 
++int wg_allowedips_slab_init(void);
++void wg_allowedips_slab_uninit(void);
++
+ #endif /* _WG_ALLOWEDIPS_H */
+--- a/drivers/net/wireguard/main.c
++++ b/drivers/net/wireguard/main.c
+@@ -21,10 +21,15 @@ static int __init mod_init(void)
+ {
+ 	int ret;
+ 
++	ret = wg_allowedips_slab_init();
++	if (ret < 0)
++		goto err_allowedips;
++
+ #ifdef DEBUG
++	ret = -ENOTRECOVERABLE;
+ 	if (!wg_allowedips_selftest() || !wg_packet_counter_selftest() ||
+ 	    !wg_ratelimiter_selftest())
+-		return -ENOTRECOVERABLE;
++		goto err_peer;
+ #endif
+ 	wg_noise_init();
+ 
+@@ -50,6 +55,8 @@ err_netlink:
+ err_device:
+ 	wg_peer_uninit();
+ err_peer:
++	wg_allowedips_slab_uninit();
++err_allowedips:
+ 	return ret;
+ }
+ 
+@@ -58,6 +65,7 @@ static void __exit mod_exit(void)
+ 	wg_genetlink_uninit();
+ 	wg_device_uninit();
+ 	wg_peer_uninit();
++	wg_allowedips_slab_uninit();
+ }
+ 
+ module_init(mod_init);
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0135-wireguard-allowedips-free-empty-intermediate-nodes-w.patch b/target/linux/generic/backport-5.4/080-wireguard-0135-wireguard-allowedips-free-empty-intermediate-nodes-w.patch
new file mode 100644
index 0000000000..c044ad25af
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0135-wireguard-allowedips-free-empty-intermediate-nodes-w.patch
@@ -0,0 +1,521 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 4 Jun 2021 17:17:38 +0200
+Subject: [PATCH] wireguard: allowedips: free empty intermediate nodes when
+ removing single node
+
+commit bf7b042dc62a31f66d3a41dd4dfc7806f267b307 upstream.
+
+When removing single nodes, it's possible that that node's parent is an
+empty intermediate node, in which case, it too should be removed.
+Otherwise the trie fills up and never is fully emptied, leading to
+gradual memory leaks over time for tries that are modified often. There
+was originally code to do this, but was removed during refactoring in
+2016 and never reworked. Now that we have proper parent pointers from
+the previous commits, we can implement this properly.
+
+In order to reduce branching and expensive comparisons, we want to keep
+the double pointer for parent assignment (which lets us easily chain up
+to the root), but we still need to actually get the parent's base
+address. So encode the bit number into the last two bits of the pointer,
+and pack and unpack it as needed. This is a little bit clumsy but is the
+fastest and less memory wasteful of the compromises. Note that we align
+the root struct here to a minimum of 4, because it's embedded into a
+larger struct, and we're relying on having the bottom two bits for our
+flag, which would only be 16-bit aligned on m68k.
+
+The existing macro-based helpers were a bit unwieldy for adding the bit
+packing to, so this commit replaces them with safer and clearer ordinary
+functions.
+
+We add a test to the randomized/fuzzer part of the selftests, to free
+the randomized tries by-peer, refuzz it, and repeat, until it's supposed
+to be empty, and then then see if that actually resulted in the whole
+thing being emptied. That combined with kmemcheck should hopefully make
+sure this commit is doing what it should. Along the way this resulted in
+various other cleanups of the tests and fixes for recent graphviz.
+
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Cc: stable@vger.kernel.org
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/allowedips.c          | 102 ++++++------
+ drivers/net/wireguard/allowedips.h          |   4 +-
+ drivers/net/wireguard/selftest/allowedips.c | 162 ++++++++++----------
+ 3 files changed, 137 insertions(+), 131 deletions(-)
+
+--- a/drivers/net/wireguard/allowedips.c
++++ b/drivers/net/wireguard/allowedips.c
+@@ -30,8 +30,11 @@ static void copy_and_assign_cidr(struct
+ 	node->bitlen = bits;
+ 	memcpy(node->bits, src, bits / 8U);
+ }
+-#define CHOOSE_NODE(parent, key) \
+-	parent->bit[(key[parent->bit_at_a] >> parent->bit_at_b) & 1]
++
++static inline u8 choose(struct allowedips_node *node, const u8 *key)
++{
++	return (key[node->bit_at_a] >> node->bit_at_b) & 1;
++}
+ 
+ static void push_rcu(struct allowedips_node **stack,
+ 		     struct allowedips_node __rcu *p, unsigned int *len)
+@@ -112,7 +115,7 @@ static struct allowedips_node *find_node
+ 			found = node;
+ 		if (node->cidr == bits)
+ 			break;
+-		node = rcu_dereference_bh(CHOOSE_NODE(node, key));
++		node = rcu_dereference_bh(node->bit[choose(node, key)]);
+ 	}
+ 	return found;
+ }
+@@ -144,8 +147,7 @@ static bool node_placement(struct allowe
+ 			   u8 cidr, u8 bits, struct allowedips_node **rnode,
+ 			   struct mutex *lock)
+ {
+-	struct allowedips_node *node = rcu_dereference_protected(trie,
+-						lockdep_is_held(lock));
++	struct allowedips_node *node = rcu_dereference_protected(trie, lockdep_is_held(lock));
+ 	struct allowedips_node *parent = NULL;
+ 	bool exact = false;
+ 
+@@ -155,13 +157,24 @@ static bool node_placement(struct allowe
+ 			exact = true;
+ 			break;
+ 		}
+-		node = rcu_dereference_protected(CHOOSE_NODE(parent, key),
+-						 lockdep_is_held(lock));
++		node = rcu_dereference_protected(parent->bit[choose(parent, key)], lockdep_is_held(lock));
+ 	}
+ 	*rnode = parent;
+ 	return exact;
+ }
+ 
++static inline void connect_node(struct allowedips_node **parent, u8 bit, struct allowedips_node *node)
++{
++	node->parent_bit_packed = (unsigned long)parent | bit;
++	rcu_assign_pointer(*parent, node);
++}
++
++static inline void choose_and_connect_node(struct allowedips_node *parent, struct allowedips_node *node)
++{
++	u8 bit = choose(parent, node->bits);
++	connect_node(&parent->bit[bit], bit, node);
++}
++
+ static int add(struct allowedips_node __rcu **trie, u8 bits, const u8 *key,
+ 	       u8 cidr, struct wg_peer *peer, struct mutex *lock)
+ {
+@@ -177,8 +190,7 @@ static int add(struct allowedips_node __
+ 		RCU_INIT_POINTER(node->peer, peer);
+ 		list_add_tail(&node->peer_list, &peer->allowedips_list);
+ 		copy_and_assign_cidr(node, key, cidr, bits);
+-		rcu_assign_pointer(node->parent_bit, trie);
+-		rcu_assign_pointer(*trie, node);
++		connect_node(trie, 2, node);
+ 		return 0;
+ 	}
+ 	if (node_placement(*trie, key, cidr, bits, &node, lock)) {
+@@ -197,10 +209,10 @@ static int add(struct allowedips_node __
+ 	if (!node) {
+ 		down = rcu_dereference_protected(*trie, lockdep_is_held(lock));
+ 	} else {
+-		down = rcu_dereference_protected(CHOOSE_NODE(node, key), lockdep_is_held(lock));
++		const u8 bit = choose(node, key);
++		down = rcu_dereference_protected(node->bit[bit], lockdep_is_held(lock));
+ 		if (!down) {
+-			rcu_assign_pointer(newnode->parent_bit, &CHOOSE_NODE(node, key));
+-			rcu_assign_pointer(CHOOSE_NODE(node, key), newnode);
++			connect_node(&node->bit[bit], bit, newnode);
+ 			return 0;
+ 		}
+ 	}
+@@ -208,15 +220,11 @@ static int add(struct allowedips_node __
+ 	parent = node;
+ 
+ 	if (newnode->cidr == cidr) {
+-		rcu_assign_pointer(down->parent_bit, &CHOOSE_NODE(newnode, down->bits));
+-		rcu_assign_pointer(CHOOSE_NODE(newnode, down->bits), down);
+-		if (!parent) {
+-			rcu_assign_pointer(newnode->parent_bit, trie);
+-			rcu_assign_pointer(*trie, newnode);
+-		} else {
+-			rcu_assign_pointer(newnode->parent_bit, &CHOOSE_NODE(parent, newnode->bits));
+-			rcu_assign_pointer(CHOOSE_NODE(parent, newnode->bits), newnode);
+-		}
++		choose_and_connect_node(newnode, down);
++		if (!parent)
++			connect_node(trie, 2, newnode);
++		else
++			choose_and_connect_node(parent, newnode);
+ 		return 0;
+ 	}
+ 
+@@ -229,17 +237,12 @@ static int add(struct allowedips_node __
+ 	INIT_LIST_HEAD(&node->peer_list);
+ 	copy_and_assign_cidr(node, newnode->bits, cidr, bits);
+ 
+-	rcu_assign_pointer(down->parent_bit, &CHOOSE_NODE(node, down->bits));
+-	rcu_assign_pointer(CHOOSE_NODE(node, down->bits), down);
+-	rcu_assign_pointer(newnode->parent_bit, &CHOOSE_NODE(node, newnode->bits));
+-	rcu_assign_pointer(CHOOSE_NODE(node, newnode->bits), newnode);
+-	if (!parent) {
+-		rcu_assign_pointer(node->parent_bit, trie);
+-		rcu_assign_pointer(*trie, node);
+-	} else {
+-		rcu_assign_pointer(node->parent_bit, &CHOOSE_NODE(parent, node->bits));
+-		rcu_assign_pointer(CHOOSE_NODE(parent, node->bits), node);
+-	}
++	choose_and_connect_node(node, down);
++	choose_and_connect_node(node, newnode);
++	if (!parent)
++		connect_node(trie, 2, node);
++	else
++		choose_and_connect_node(parent, node);
+ 	return 0;
+ }
+ 
+@@ -297,7 +300,8 @@ int wg_allowedips_insert_v6(struct allow
+ void wg_allowedips_remove_by_peer(struct allowedips *table,
+ 				  struct wg_peer *peer, struct mutex *lock)
+ {
+-	struct allowedips_node *node, *child, *tmp;
++	struct allowedips_node *node, *child, **parent_bit, *parent, *tmp;
++	bool free_parent;
+ 
+ 	if (list_empty(&peer->allowedips_list))
+ 		return;
+@@ -307,19 +311,29 @@ void wg_allowedips_remove_by_peer(struct
+ 		RCU_INIT_POINTER(node->peer, NULL);
+ 		if (node->bit[0] && node->bit[1])
+ 			continue;
+-		child = rcu_dereference_protected(
+-				node->bit[!rcu_access_pointer(node->bit[0])],
+-				lockdep_is_held(lock));
++		child = rcu_dereference_protected(node->bit[!rcu_access_pointer(node->bit[0])],
++						  lockdep_is_held(lock));
+ 		if (child)
+-			child->parent_bit = node->parent_bit;
+-		*rcu_dereference_protected(node->parent_bit, lockdep_is_held(lock)) = child;
++			child->parent_bit_packed = node->parent_bit_packed;
++		parent_bit = (struct allowedips_node **)(node->parent_bit_packed & ~3UL);
++		*parent_bit = child;
++		parent = (void *)parent_bit -
++			 offsetof(struct allowedips_node, bit[node->parent_bit_packed & 1]);
++		free_parent = !rcu_access_pointer(node->bit[0]) &&
++			      !rcu_access_pointer(node->bit[1]) &&
++			      (node->parent_bit_packed & 3) <= 1 &&
++			      !rcu_access_pointer(parent->peer);
++		if (free_parent)
++			child = rcu_dereference_protected(
++					parent->bit[!(node->parent_bit_packed & 1)],
++					lockdep_is_held(lock));
+ 		call_rcu(&node->rcu, node_free_rcu);
+-
+-		/* TODO: Note that we currently don't walk up and down in order to
+-		 * free any potential filler nodes. This means that this function
+-		 * doesn't free up as much as it could, which could be revisited
+-		 * at some point.
+-		 */
++		if (!free_parent)
++			continue;
++		if (child)
++			child->parent_bit_packed = parent->parent_bit_packed;
++		*(struct allowedips_node **)(parent->parent_bit_packed & ~3UL) = child;
++		call_rcu(&parent->rcu, node_free_rcu);
+ 	}
+ }
+ 
+--- a/drivers/net/wireguard/allowedips.h
++++ b/drivers/net/wireguard/allowedips.h
+@@ -19,7 +19,7 @@ struct allowedips_node {
+ 	u8 bits[16] __aligned(__alignof(u64));
+ 
+ 	/* Keep rarely used members at bottom to be beyond cache line. */
+-	struct allowedips_node *__rcu *parent_bit;
++	unsigned long parent_bit_packed;
+ 	union {
+ 		struct list_head peer_list;
+ 		struct rcu_head rcu;
+@@ -30,7 +30,7 @@ struct allowedips {
+ 	struct allowedips_node __rcu *root4;
+ 	struct allowedips_node __rcu *root6;
+ 	u64 seq;
+-};
++} __aligned(4); /* We pack the lower 2 bits of &root, but m68k only gives 16-bit alignment. */
+ 
+ void wg_allowedips_init(struct allowedips *table);
+ void wg_allowedips_free(struct allowedips *table, struct mutex *mutex);
+--- a/drivers/net/wireguard/selftest/allowedips.c
++++ b/drivers/net/wireguard/selftest/allowedips.c
+@@ -19,32 +19,22 @@
+ 
+ #include <linux/siphash.h>
+ 
+-static __init void swap_endian_and_apply_cidr(u8 *dst, const u8 *src, u8 bits,
+-					      u8 cidr)
+-{
+-	swap_endian(dst, src, bits);
+-	memset(dst + (cidr + 7) / 8, 0, bits / 8 - (cidr + 7) / 8);
+-	if (cidr)
+-		dst[(cidr + 7) / 8 - 1] &= ~0U << ((8 - (cidr % 8)) % 8);
+-}
+-
+ static __init void print_node(struct allowedips_node *node, u8 bits)
+ {
+ 	char *fmt_connection = KERN_DEBUG "\t\"%p/%d\" -> \"%p/%d\";\n";
+-	char *fmt_declaration = KERN_DEBUG
+-		"\t\"%p/%d\"[style=%s, color=\"#%06x\"];\n";
++	char *fmt_declaration = KERN_DEBUG "\t\"%p/%d\"[style=%s, color=\"#%06x\"];\n";
++	u8 ip1[16], ip2[16], cidr1, cidr2;
+ 	char *style = "dotted";
+-	u8 ip1[16], ip2[16];
+ 	u32 color = 0;
+ 
++	if (node == NULL)
++		return;
+ 	if (bits == 32) {
+ 		fmt_connection = KERN_DEBUG "\t\"%pI4/%d\" -> \"%pI4/%d\";\n";
+-		fmt_declaration = KERN_DEBUG
+-			"\t\"%pI4/%d\"[style=%s, color=\"#%06x\"];\n";
++		fmt_declaration = KERN_DEBUG "\t\"%pI4/%d\"[style=%s, color=\"#%06x\"];\n";
+ 	} else if (bits == 128) {
+ 		fmt_connection = KERN_DEBUG "\t\"%pI6/%d\" -> \"%pI6/%d\";\n";
+-		fmt_declaration = KERN_DEBUG
+-			"\t\"%pI6/%d\"[style=%s, color=\"#%06x\"];\n";
++		fmt_declaration = KERN_DEBUG "\t\"%pI6/%d\"[style=%s, color=\"#%06x\"];\n";
+ 	}
+ 	if (node->peer) {
+ 		hsiphash_key_t key = { { 0 } };
+@@ -55,24 +45,20 @@ static __init void print_node(struct all
+ 			hsiphash_1u32(0xabad1dea, &key) % 200;
+ 		style = "bold";
+ 	}
+-	swap_endian_and_apply_cidr(ip1, node->bits, bits, node->cidr);
+-	printk(fmt_declaration, ip1, node->cidr, style, color);
++	wg_allowedips_read_node(node, ip1, &cidr1);
++	printk(fmt_declaration, ip1, cidr1, style, color);
+ 	if (node->bit[0]) {
+-		swap_endian_and_apply_cidr(ip2,
+-				rcu_dereference_raw(node->bit[0])->bits, bits,
+-				node->cidr);
+-		printk(fmt_connection, ip1, node->cidr, ip2,
+-		       rcu_dereference_raw(node->bit[0])->cidr);
+-		print_node(rcu_dereference_raw(node->bit[0]), bits);
++		wg_allowedips_read_node(rcu_dereference_raw(node->bit[0]), ip2, &cidr2);
++		printk(fmt_connection, ip1, cidr1, ip2, cidr2);
+ 	}
+ 	if (node->bit[1]) {
+-		swap_endian_and_apply_cidr(ip2,
+-				rcu_dereference_raw(node->bit[1])->bits,
+-				bits, node->cidr);
+-		printk(fmt_connection, ip1, node->cidr, ip2,
+-		       rcu_dereference_raw(node->bit[1])->cidr);
+-		print_node(rcu_dereference_raw(node->bit[1]), bits);
++		wg_allowedips_read_node(rcu_dereference_raw(node->bit[1]), ip2, &cidr2);
++		printk(fmt_connection, ip1, cidr1, ip2, cidr2);
+ 	}
++	if (node->bit[0])
++		print_node(rcu_dereference_raw(node->bit[0]), bits);
++	if (node->bit[1])
++		print_node(rcu_dereference_raw(node->bit[1]), bits);
+ }
+ 
+ static __init void print_tree(struct allowedips_node __rcu *top, u8 bits)
+@@ -121,8 +107,8 @@ static __init inline union nf_inet_addr
+ {
+ 	union nf_inet_addr mask;
+ 
+-	memset(&mask, 0x00, 128 / 8);
+-	memset(&mask, 0xff, cidr / 8);
++	memset(&mask, 0, sizeof(mask));
++	memset(&mask.all, 0xff, cidr / 8);
+ 	if (cidr % 32)
+ 		mask.all[cidr / 32] = (__force u32)htonl(
+ 			(0xFFFFFFFFUL << (32 - (cidr % 32))) & 0xFFFFFFFFUL);
+@@ -149,42 +135,36 @@ horrible_mask_self(struct horrible_allow
+ }
+ 
+ static __init inline bool
+-horrible_match_v4(const struct horrible_allowedips_node *node,
+-		  struct in_addr *ip)
++horrible_match_v4(const struct horrible_allowedips_node *node, struct in_addr *ip)
+ {
+ 	return (ip->s_addr & node->mask.ip) == node->ip.ip;
+ }
+ 
+ static __init inline bool
+-horrible_match_v6(const struct horrible_allowedips_node *node,
+-		  struct in6_addr *ip)
++horrible_match_v6(const struct horrible_allowedips_node *node, struct in6_addr *ip)
+ {
+-	return (ip->in6_u.u6_addr32[0] & node->mask.ip6[0]) ==
+-		       node->ip.ip6[0] &&
+-	       (ip->in6_u.u6_addr32[1] & node->mask.ip6[1]) ==
+-		       node->ip.ip6[1] &&
+-	       (ip->in6_u.u6_addr32[2] & node->mask.ip6[2]) ==
+-		       node->ip.ip6[2] &&
++	return (ip->in6_u.u6_addr32[0] & node->mask.ip6[0]) == node->ip.ip6[0] &&
++	       (ip->in6_u.u6_addr32[1] & node->mask.ip6[1]) == node->ip.ip6[1] &&
++	       (ip->in6_u.u6_addr32[2] & node->mask.ip6[2]) == node->ip.ip6[2] &&
+ 	       (ip->in6_u.u6_addr32[3] & node->mask.ip6[3]) == node->ip.ip6[3];
+ }
+ 
+ static __init void
+-horrible_insert_ordered(struct horrible_allowedips *table,
+-			struct horrible_allowedips_node *node)
++horrible_insert_ordered(struct horrible_allowedips *table, struct horrible_allowedips_node *node)
+ {
+ 	struct horrible_allowedips_node *other = NULL, *where = NULL;
+ 	u8 my_cidr = horrible_mask_to_cidr(node->mask);
+ 
+ 	hlist_for_each_entry(other, &table->head, table) {
+-		if (!memcmp(&other->mask, &node->mask,
+-			    sizeof(union nf_inet_addr)) &&
+-		    !memcmp(&other->ip, &node->ip,
+-			    sizeof(union nf_inet_addr)) &&
+-		    other->ip_version == node->ip_version) {
++		if (other->ip_version == node->ip_version &&
++		    !memcmp(&other->mask, &node->mask, sizeof(union nf_inet_addr)) &&
++		    !memcmp(&other->ip, &node->ip, sizeof(union nf_inet_addr))) {
+ 			other->value = node->value;
+ 			kfree(node);
+ 			return;
+ 		}
++	}
++	hlist_for_each_entry(other, &table->head, table) {
+ 		where = other;
+ 		if (horrible_mask_to_cidr(other->mask) <= my_cidr)
+ 			break;
+@@ -201,8 +181,7 @@ static __init int
+ horrible_allowedips_insert_v4(struct horrible_allowedips *table,
+ 			      struct in_addr *ip, u8 cidr, void *value)
+ {
+-	struct horrible_allowedips_node *node = kzalloc(sizeof(*node),
+-							GFP_KERNEL);
++	struct horrible_allowedips_node *node = kzalloc(sizeof(*node), GFP_KERNEL);
+ 
+ 	if (unlikely(!node))
+ 		return -ENOMEM;
+@@ -219,8 +198,7 @@ static __init int
+ horrible_allowedips_insert_v6(struct horrible_allowedips *table,
+ 			      struct in6_addr *ip, u8 cidr, void *value)
+ {
+-	struct horrible_allowedips_node *node = kzalloc(sizeof(*node),
+-							GFP_KERNEL);
++	struct horrible_allowedips_node *node = kzalloc(sizeof(*node), GFP_KERNEL);
+ 
+ 	if (unlikely(!node))
+ 		return -ENOMEM;
+@@ -234,39 +212,43 @@ horrible_allowedips_insert_v6(struct hor
+ }
+ 
+ static __init void *
+-horrible_allowedips_lookup_v4(struct horrible_allowedips *table,
+-			      struct in_addr *ip)
++horrible_allowedips_lookup_v4(struct horrible_allowedips *table, struct in_addr *ip)
+ {
+ 	struct horrible_allowedips_node *node;
+-	void *ret = NULL;
+ 
+ 	hlist_for_each_entry(node, &table->head, table) {
+-		if (node->ip_version != 4)
+-			continue;
+-		if (horrible_match_v4(node, ip)) {
+-			ret = node->value;
+-			break;
+-		}
++		if (node->ip_version == 4 && horrible_match_v4(node, ip))
++			return node->value;
+ 	}
+-	return ret;
++	return NULL;
+ }
+ 
+ static __init void *
+-horrible_allowedips_lookup_v6(struct horrible_allowedips *table,
+-			      struct in6_addr *ip)
++horrible_allowedips_lookup_v6(struct horrible_allowedips *table, struct in6_addr *ip)
+ {
+ 	struct horrible_allowedips_node *node;
+-	void *ret = NULL;
+ 
+ 	hlist_for_each_entry(node, &table->head, table) {
+-		if (node->ip_version != 6)
++		if (node->ip_version == 6 && horrible_match_v6(node, ip))
++			return node->value;
++	}
++	return NULL;
++}
++
++
++static __init void
++horrible_allowedips_remove_by_value(struct horrible_allowedips *table, void *value)
++{
++	struct horrible_allowedips_node *node;
++	struct hlist_node *h;
++
++	hlist_for_each_entry_safe(node, h, &table->head, table) {
++		if (node->value != value)
+ 			continue;
+-		if (horrible_match_v6(node, ip)) {
+-			ret = node->value;
+-			break;
+-		}
++		hlist_del(&node->table);
++		kfree(node);
+ 	}
+-	return ret;
++
+ }
+ 
+ static __init bool randomized_test(void)
+@@ -397,23 +379,33 @@ static __init bool randomized_test(void)
+ 		print_tree(t.root6, 128);
+ 	}
+ 
+-	for (i = 0; i < NUM_QUERIES; ++i) {
+-		prandom_bytes(ip, 4);
+-		if (lookup(t.root4, 32, ip) !=
+-		    horrible_allowedips_lookup_v4(&h, (struct in_addr *)ip)) {
+-			pr_err("allowedips random self-test: FAIL\n");
+-			goto free;
++	for (j = 0;; ++j) {
++		for (i = 0; i < NUM_QUERIES; ++i) {
++			prandom_bytes(ip, 4);
++			if (lookup(t.root4, 32, ip) != horrible_allowedips_lookup_v4(&h, (struct in_addr *)ip)) {
++				horrible_allowedips_lookup_v4(&h, (struct in_addr *)ip);
++				pr_err("allowedips random v4 self-test: FAIL\n");
++				goto free;
++			}
++			prandom_bytes(ip, 16);
++			if (lookup(t.root6, 128, ip) != horrible_allowedips_lookup_v6(&h, (struct in6_addr *)ip)) {
++				pr_err("allowedips random v6 self-test: FAIL\n");
++				goto free;
++			}
+ 		}
++		if (j >= NUM_PEERS)
++			break;
++		mutex_lock(&mutex);
++		wg_allowedips_remove_by_peer(&t, peers[j], &mutex);
++		mutex_unlock(&mutex);
++		horrible_allowedips_remove_by_value(&h, peers[j]);
+ 	}
+ 
+-	for (i = 0; i < NUM_QUERIES; ++i) {
+-		prandom_bytes(ip, 16);
+-		if (lookup(t.root6, 128, ip) !=
+-		    horrible_allowedips_lookup_v6(&h, (struct in6_addr *)ip)) {
+-			pr_err("allowedips random self-test: FAIL\n");
+-			goto free;
+-		}
++	if (t.root4 || t.root6) {
++		pr_err("allowedips random self-test removal: FAIL\n");
++		goto free;
+ 	}
++
+ 	ret = true;
+ 
+ free: