[PATCH AUTOSEL 5.9 22/55] mac80211: fix use of skb payload instead of header

[PATCH AUTOSEL 5.9 22/55] mac80211: fix use of skb payload instead of header

[Sasha Levin]

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 14f46c1e5108696ec1e5a129e838ecedf108c7bf ]

When ieee80211_skb_resize() is called from ieee80211_build_hdr()
the skb has no 802.11 header yet, in fact it consist only of the
payload as the ethernet frame is removed. As such, we're using
the payload data for ieee80211_is_mgmt(), which is of course
completely wrong. This didn't really hurt us because these are
always data frames, so we could only have added more tailroom
than we needed if we determined it was a management frame and
sdata->crypto_tx_tailroom_needed_cnt was false.

However, syzbot found that of course there need not be any payload,
so we're using at best uninitialized memory for the check.

Fix this to pass explicitly the kind of frame that we have instead
of checking there, by replacing the "bool may_encrypt" argument
with an argument that can carry the three possible states - it's
not going to be encrypted, it's a management frame, or it's a data
frame (and then we check sdata->crypto_tx_tailroom_needed_cnt).

Reported-by: syzbot+32fd1a1bfe355e93f1e2@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20201009132538.e1fd7f802947.I799b288466ea2815f9d4c84349fae697dca2f189@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mac80211/tx.c | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 282b0bc201eeb..b82d6cfd6aaf4 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1938,19 +1938,24 @@ static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
 
 /* device xmit handlers */
 
+enum ieee80211_encrypt {
+	ENCRYPT_NO,
+	ENCRYPT_MGMT,
+	ENCRYPT_DATA,
+};
+
 static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
 				struct sk_buff *skb,
-				int head_need, bool may_encrypt)
+				int head_need,
+				enum ieee80211_encrypt encrypt)
 {
 	struct ieee80211_local *local = sdata->local;
-	struct ieee80211_hdr *hdr;
 	bool enc_tailroom;
 	int tail_need = 0;
 
-	hdr = (struct ieee80211_hdr *) skb->data;
-	enc_tailroom = may_encrypt &&
-		       (sdata->crypto_tx_tailroom_needed_cnt ||
-			ieee80211_is_mgmt(hdr->frame_control));
+	enc_tailroom = encrypt == ENCRYPT_MGMT ||
+		       (encrypt == ENCRYPT_DATA &&
+			sdata->crypto_tx_tailroom_needed_cnt);
 
 	if (enc_tailroom) {
 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
@@ -1981,23 +1986,29 @@ void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	struct ieee80211_hdr *hdr;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	int headroom;
-	bool may_encrypt;
+	enum ieee80211_encrypt encrypt;
 
-	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
+	if (info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT)
+		encrypt = ENCRYPT_NO;
+	else if (ieee80211_is_mgmt(hdr->frame_control))
+		encrypt = ENCRYPT_MGMT;
+	else
+		encrypt = ENCRYPT_DATA;
 
 	headroom = local->tx_headroom;
-	if (may_encrypt)
+	if (encrypt != ENCRYPT_NO)
 		headroom += sdata->encrypt_headroom;
 	headroom -= skb_headroom(skb);
 	headroom = max_t(int, 0, headroom);
 
-	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
+	if (ieee80211_skb_resize(sdata, skb, headroom, encrypt)) {
 		ieee80211_free_txskb(&local->hw, skb);
 		return;
 	}
 
+	/* reload after potential resize */
 	hdr = (struct ieee80211_hdr *) skb->data;
 	info->control.vif = &sdata->vif;
 
@@ -2822,7 +2833,7 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
 		head_need += sdata->encrypt_headroom;
 		head_need += local->tx_headroom;
 		head_need = max_t(int, 0, head_need);
-		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
+		if (ieee80211_skb_resize(sdata, skb, head_need, ENCRYPT_DATA)) {
 			ieee80211_free_txskb(&local->hw, skb);
 			skb = NULL;
 			return ERR_PTR(-ENOMEM);
@@ -3496,7 +3507,7 @@ static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
 	if (unlikely(ieee80211_skb_resize(sdata, skb,
 					  max_t(int, extra_head + hw_headroom -
 						     skb_headroom(skb), 0),
-					  false))) {
+					  ENCRYPT_NO))) {
 		kfree_skb(skb);
 		return true;
 	}
-- 
2.27.0

[PATCH AUTOSEL 5.9 23/55] cfg80211: initialize wdev data earlier

[Sasha Levin]

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 9bdaf3b91efd229dd272b228e13df10310c80d19 ]

There's a race condition in the netdev registration in that
NETDEV_REGISTER actually happens after the netdev is available,
and so if we initialize things only there, we might get called
with an uninitialized wdev through nl80211 - not using a wdev
but using a netdev interface index.

I found this while looking into a syzbot report, but it doesn't
really seem to be related, and unfortunately there's no repro
for it (yet). I can't (yet) explain how it managed to get into
cfg80211_release_pmsr() from nl80211_netlink_notify() without
the wdev having been initialized, as the latter only iterates
the wdevs that are linked into the rdev, which even without the
change here happened after init.

However, looking at this, it seems fairly clear that the init
needs to be done earlier, otherwise we might even re-init on a
netns move, when data might still be pending.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20201009135821.fdcbba3aad65.Ie9201d91dbcb7da32318812effdc1561aeaf4cdc@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/wireless/core.c    | 57 +++++++++++++++++++++++-------------------
 net/wireless/core.h    |  5 ++--
 net/wireless/nl80211.c |  3 ++-
 3 files changed, 36 insertions(+), 29 deletions(-)

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 354b0ccbdc240..e025493171262 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -1248,8 +1248,7 @@ void cfg80211_stop_iface(struct wiphy *wiphy, struct wireless_dev *wdev,
 }
 EXPORT_SYMBOL(cfg80211_stop_iface);
 
-void cfg80211_init_wdev(struct cfg80211_registered_device *rdev,
-			struct wireless_dev *wdev)
+void cfg80211_init_wdev(struct wireless_dev *wdev)
 {
 	mutex_init(&wdev->mtx);
 	INIT_LIST_HEAD(&wdev->event_list);
@@ -1260,6 +1259,30 @@ void cfg80211_init_wdev(struct cfg80211_registered_device *rdev,
 	spin_lock_init(&wdev->pmsr_lock);
 	INIT_WORK(&wdev->pmsr_free_wk, cfg80211_pmsr_free_wk);
 
+#ifdef CONFIG_CFG80211_WEXT
+	wdev->wext.default_key = -1;
+	wdev->wext.default_mgmt_key = -1;
+	wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
+#endif
+
+	if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT)
+		wdev->ps = true;
+	else
+		wdev->ps = false;
+	/* allow mac80211 to determine the timeout */
+	wdev->ps_timeout = -1;
+
+	if ((wdev->iftype == NL80211_IFTYPE_STATION ||
+	     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
+	     wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
+		wdev->netdev->priv_flags |= IFF_DONT_BRIDGE;
+
+	INIT_WORK(&wdev->disconnect_wk, cfg80211_autodisconnect_wk);
+}
+
+void cfg80211_register_wdev(struct cfg80211_registered_device *rdev,
+			    struct wireless_dev *wdev)
+{
 	/*
 	 * We get here also when the interface changes network namespaces,
 	 * as it's registered into the new one, but we don't want it to
@@ -1293,6 +1316,11 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 	switch (state) {
 	case NETDEV_POST_INIT:
 		SET_NETDEV_DEVTYPE(dev, &wiphy_type);
+		wdev->netdev = dev;
+		/* can only change netns with wiphy */
+		dev->features |= NETIF_F_NETNS_LOCAL;
+
+		cfg80211_init_wdev(wdev);
 		break;
 	case NETDEV_REGISTER:
 		/*
@@ -1300,35 +1328,12 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		 * called within code protected by it when interfaces
 		 * are added with nl80211.
 		 */
-		/* can only change netns with wiphy */
-		dev->features |= NETIF_F_NETNS_LOCAL;
-
 		if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 				      "phy80211")) {
 			pr_err("failed to add phy80211 symlink to netdev!\n");
 		}
-		wdev->netdev = dev;
-#ifdef CONFIG_CFG80211_WEXT
-		wdev->wext.default_key = -1;
-		wdev->wext.default_mgmt_key = -1;
-		wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
-#endif
-
-		if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT)
-			wdev->ps = true;
-		else
-			wdev->ps = false;
-		/* allow mac80211 to determine the timeout */
-		wdev->ps_timeout = -1;
-
-		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
-		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
-		     wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
-			dev->priv_flags |= IFF_DONT_BRIDGE;
-
-		INIT_WORK(&wdev->disconnect_wk, cfg80211_autodisconnect_wk);
 
-		cfg80211_init_wdev(rdev, wdev);
+		cfg80211_register_wdev(rdev, wdev);
 		break;
 	case NETDEV_GOING_DOWN:
 		cfg80211_leave(rdev, wdev);
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 67b0389fca4dc..8cd4a9793298e 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -208,8 +208,9 @@ struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx);
 int cfg80211_switch_netns(struct cfg80211_registered_device *rdev,
 			  struct net *net);
 
-void cfg80211_init_wdev(struct cfg80211_registered_device *rdev,
-			struct wireless_dev *wdev);
+void cfg80211_init_wdev(struct wireless_dev *wdev);
+void cfg80211_register_wdev(struct cfg80211_registered_device *rdev,
+			    struct wireless_dev *wdev);
 
 static inline void wdev_lock(struct wireless_dev *wdev)
 	__acquires(wdev)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index e14307f2bddcc..8eb43c47e582a 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3801,7 +3801,8 @@ static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
 		 * P2P Device and NAN do not have a netdev, so don't go
 		 * through the netdev notifier and must be added here
 		 */
-		cfg80211_init_wdev(rdev, wdev);
+		cfg80211_init_wdev(wdev);
+		cfg80211_register_wdev(rdev, wdev);
 		break;
 	default:
 		break;
-- 
2.27.0

[PATCH AUTOSEL 5.9 24/55] mac80211: always wind down STA state

[Sasha Levin]

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit dcd479e10a0510522a5d88b29b8f79ea3467d501 ]

When (for example) an IBSS station is pre-moved to AUTHORIZED
before it's inserted, and then the insertion fails, we don't
clean up the fast RX/TX states that might already have been
created, since we don't go through all the state transitions
again on the way down.

Do that, if it hasn't been done already, when the station is
freed. I considered only freeing the fast TX/RX state there,
but we might add more state so it's more robust to wind down
the state properly.

Note that we warn if the station was ever inserted, it should
have been properly cleaned up in that case, and the driver
will probably not like things happening out of order.

Reported-by: syzbot+2e293dbd67de2836ba42@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20201009141710.7223b322a955.I95bd08b9ad0e039c034927cce0b75beea38e059b@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mac80211/sta_info.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index fb4f2b9b294f0..4fe284ff1ea3d 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -258,6 +258,24 @@ struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
  */
 void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
 {
+	/*
+	 * If we had used sta_info_pre_move_state() then we might not
+	 * have gone through the state transitions down again, so do
+	 * it here now (and warn if it's inserted).
+	 *
+	 * This will clear state such as fast TX/RX that may have been
+	 * allocated during state transitions.
+	 */
+	while (sta->sta_state > IEEE80211_STA_NONE) {
+		int ret;
+
+		WARN_ON_ONCE(test_sta_flag(sta, WLAN_STA_INSERTED));
+
+		ret = sta_info_move_state(sta, sta->sta_state - 1);
+		if (WARN_ONCE(ret, "sta_info_move_state() returned %d\n", ret))
+			break;
+	}
+
 	if (sta->rate_ctrl)
 		rate_control_free_sta(sta);
 
-- 
2.27.0

[PATCH AUTOSEL 5.9 25/55] cfg80211: regulatory: Fix inconsistent format argument

[Sasha Levin]

From: Ye Bin <yebin10@huawei.com>

[ Upstream commit db18d20d1cb0fde16d518fb5ccd38679f174bc04 ]

Fix follow warning:
[net/wireless/reg.c:3619]: (warning) %d in format string (no. 2)
requires 'int' but the argument type is 'unsigned int'.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20201009070215.63695-1-yebin10@huawei.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/wireless/reg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index d8a90d3974235..763a45655ac21 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -3411,7 +3411,7 @@ static void print_rd_rules(const struct ieee80211_regdomain *rd)
 		power_rule = &reg_rule->power_rule;
 
 		if (reg_rule->flags & NL80211_RRF_AUTO_BW)
-			snprintf(bw, sizeof(bw), "%d KHz, %d KHz AUTO",
+			snprintf(bw, sizeof(bw), "%d KHz, %u KHz AUTO",
 				 freq_range->max_bandwidth_khz,
 				 reg_get_max_bandwidth(rd, reg_rule));
 		else
-- 
2.27.0

[PATCH AUTOSEL 5.9 26/55] wireguard: selftests: check that route_me_harder packets use the right sk

[Sasha Levin]

From: "Jason A. Donenfeld" <Jason@zx2c4.com>

[ Upstream commit af8afcf1fdd5f365f70e2386c2d8c7a1abd853d7 ]

If netfilter changes the packet mark, the packet is rerouted. The
ip_route_me_harder family of functions fails to use the right sk, opting
to instead use skb->sk, resulting in a routing loop when used with
tunnels. With the next change fixing this issue in netfilter, test for
the relevant condition inside our test suite, since wireguard was where
the bug was discovered.

Reported-by: Chen Minqiang <ptpt52@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/wireguard/netns.sh           | 8 ++++++++
 tools/testing/selftests/wireguard/qemu/kernel.config | 2 ++
 2 files changed, 10 insertions(+)

diff --git a/tools/testing/selftests/wireguard/netns.sh b/tools/testing/selftests/wireguard/netns.sh
index d77f4829f1e07..74c69b75f6f5a 100755
--- a/tools/testing/selftests/wireguard/netns.sh
+++ b/tools/testing/selftests/wireguard/netns.sh
@@ -316,6 +316,14 @@ pp sleep 3
 n2 ping -W 1 -c 1 192.168.241.1
 n1 wg set wg0 peer "$pub2" persistent-keepalive 0
 
+# Test that sk_bound_dev_if works
+n1 ping -I wg0 -c 1 -W 1 192.168.241.2
+# What about when the mark changes and the packet must be rerouted?
+n1 iptables -t mangle -I OUTPUT -j MARK --set-xmark 1
+n1 ping -c 1 -W 1 192.168.241.2 # First the boring case
+n1 ping -I wg0 -c 1 -W 1 192.168.241.2 # Then the sk_bound_dev_if case
+n1 iptables -t mangle -D OUTPUT -j MARK --set-xmark 1
+
 # Test that onion routing works, even when it loops
 n1 wg set wg0 peer "$pub3" allowed-ips 192.168.242.2/32 endpoint 192.168.241.2:5
 ip1 addr add 192.168.242.1/24 dev wg0
diff --git a/tools/testing/selftests/wireguard/qemu/kernel.config b/tools/testing/selftests/wireguard/qemu/kernel.config
index d531de13c95b0..4eecb432a66c1 100644
--- a/tools/testing/selftests/wireguard/qemu/kernel.config
+++ b/tools/testing/selftests/wireguard/qemu/kernel.config
@@ -18,10 +18,12 @@ CONFIG_NF_NAT=y
 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
+CONFIG_IP_NF_MANGLE=y
 CONFIG_IP_NF_NAT=y
 CONFIG_IP_ADVANCED_ROUTER=y
 CONFIG_IP_MULTIPLE_TABLES=y
-- 
2.27.0

[PATCH AUTOSEL 5.9 42/55] net: usb: qmi_wwan: add Telit LE910Cx 0x1230 composition

[Sasha Levin]

From: Daniele Palmas <dnlplm@gmail.com>

[ Upstream commit 5fd8477ed8ca77e64b93d44a6dae4aa70c191396 ]

Add support for Telit LE910Cx 0x1230 composition:

0x1230: tty, adb, rmnet, audio, tty, tty, tty, tty

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Link: https://lore.kernel.org/r/20201102110108.17244-1-dnlplm@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/usb/qmi_wwan.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index 5ca1356b8656f..3db5b5d104798 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -1331,6 +1331,7 @@ static const struct usb_device_id products[] = {
 	{QMI_FIXED_INTF(0x1bc7, 0x1101, 3)},	/* Telit ME910 dual modem */
 	{QMI_FIXED_INTF(0x1bc7, 0x1200, 5)},	/* Telit LE920 */
 	{QMI_QUIRK_SET_DTR(0x1bc7, 0x1201, 2)},	/* Telit LE920, LE920A4 */
+	{QMI_QUIRK_SET_DTR(0x1bc7, 0x1230, 2)},	/* Telit LE910Cx */
 	{QMI_QUIRK_SET_DTR(0x1bc7, 0x1260, 2)},	/* Telit LE910Cx */
 	{QMI_QUIRK_SET_DTR(0x1bc7, 0x1261, 2)},	/* Telit LE910Cx */
 	{QMI_QUIRK_SET_DTR(0x1bc7, 0x1900, 1)},	/* Telit LN940 series */
-- 
2.27.0

Re: [PATCH AUTOSEL 5.9 26/55] wireguard: selftests: check that route_me_harder packets use the right sk

[Jason A. Donenfeld]

Note that this requires
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=46d6c5ae953cc0be38efd0e469284df7c4328cf8
And that commit should be backported to every kernel ever, since the
bug is so old.

Re: [PATCH AUTOSEL 5.9 26/55] wireguard: selftests: check that route_me_harder packets use the right sk

[Greg KH]

On Tue, Nov 10, 2020 at 01:29:41PM +0100, Jason A. Donenfeld wrote:
> Note that this requires
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=46d6c5ae953cc0be38efd0e469284df7c4328cf8
> And that commit should be backported to every kernel ever, since the
> bug is so old.

Sasha queued this up to 5.4.y and 5.9.y, but it looks like it doesn't
easily apply to older kernels.  If you think that it's needed beyond
that, I'll gladly take backported patches.

thanks,

greg k-h

Re: [PATCH AUTOSEL 5.9 26/55] wireguard: selftests: check that route_me_harder packets use the right sk

[Jason A. Donenfeld]

On Tue, Nov 10, 2020 at 6:20 PM Greg KH <greg@kroah.com> wrote:
>
> On Tue, Nov 10, 2020 at 01:29:41PM +0100, Jason A. Donenfeld wrote:
> > Note that this requires
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=46d6c5ae953cc0be38efd0e469284df7c4328cf8
> > And that commit should be backported to every kernel ever, since the
> > bug is so old.
>
> Sasha queued this up to 5.4.y and 5.9.y, but it looks like it doesn't
> easily apply to older kernels.  If you think that it's needed beyond
> that, I'll gladly take backported patches.

Backport to older kernels coming your way shortly.