FAILED: patch "[PATCH] mptcp: pm: fix backup support in signal endpoints" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] mptcp: pm: fix backup support in signal endpoints" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 6834097fc38c5416701c793da94558cea49c0a1f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024080729-unclaimed-shopping-6751@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

6834097fc38c ("mptcp: pm: fix backup support in signal endpoints")
9ae7846c4b6b ("mptcp: dump addrs in userspace pm list")
34e74a5cf3b7 ("mptcp: implement mptcp_userspace_pm_dump_addr")
aab4d8564947 ("net: mptcp: use policy generated by YAML spec")
1e07938e29c5 ("net: mptcp: rename netlink handlers to mptcp_pm_nl_<blah>_{doit,dumpit}")
1d0507f46843 ("net: mptcp: convert netlink from small_ops to ops")
740ebe35bd3f ("mptcp: add struct mptcp_sched_ops")
6ba7ce89905c ("mptcp: unify pm set_flags interfaces")
f40be0db0b76 ("mptcp: unify pm get_flags_and_ifindex_by_id")
a963853fd465 ("mptcp: use net instead of sock_net")
dfc8d0603033 ("mptcp: implement delayed seq generation for passive fastopen")
d15697185404 ("mptcp: allow privileged operations from user namespaces")
9c5d03d36251 ("genetlink: start to validate reserved header bytes")
02739545951a ("net: Fix data-races around sysctl_[rw]mem(_offset)?.")
892f396c8e68 ("mptcp: netlink: issue MP_PRIO signals from userspace PMs")
a657430260e5 ("mptcp: Acquire the subflow socket lock before modifying MP_PRIO flags")
c21b50d5912b ("mptcp: Avoid acquiring PM lock for subflow priority changes")
6f664045c868 ("Merge tag 'mm-nonmm-stable-2022-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6834097fc38c5416701c793da94558cea49c0a1f Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: Sat, 27 Jul 2024 12:01:28 +0200
Subject: [PATCH] mptcp: pm: fix backup support in signal endpoints

There was a support for signal endpoints, but only when the endpoint's
flag was changed during a connection. If an endpoint with the signal and
backup was already present, the MP_JOIN reply was not containing the
backup flag as expected.

That's confusing to have this inconsistent behaviour. On the other hand,
the infrastructure to set the backup flag in the SYN + ACK + MP_JOIN was
already there, it was just never set before. Now when requesting the
local ID from the path-manager, the backup status is also requested.

Note that when the userspace PM is used, the backup flag can be set if
the local address was already used before with a backup flag, e.g. if
the address was announced with the 'backup' flag, or a subflow was
created with the 'backup' flag.

Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/507
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 55406720c607..23bb89c94e90 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -426,6 +426,18 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	return mptcp_pm_nl_get_local_id(msk, &skc_local);
 }
 
+bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
+{
+	struct mptcp_addr_info skc_local;
+
+	mptcp_local_address((struct sock_common *)skc, &skc_local);
+
+	if (mptcp_pm_is_userspace(msk))
+		return mptcp_userspace_pm_is_backup(msk, &skc_local);
+
+	return mptcp_pm_nl_is_backup(msk, &skc_local);
+}
+
 int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
 					 u8 *flags, int *ifindex)
 {
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 7635fac91539..37954a0b087d 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1101,6 +1101,24 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc
 	return ret;
 }
 
+bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
+{
+	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
+	struct mptcp_pm_addr_entry *entry;
+	bool backup = false;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
+		if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) {
+			backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	return backup;
+}
+
 #define MPTCP_PM_CMD_GRP_OFFSET       0
 #define MPTCP_PM_EV_GRP_OFFSET        1
 
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index f0a4590506c6..8eaa9fbe3e34 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -165,6 +165,24 @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true);
 }
 
+bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
+				  struct mptcp_addr_info *skc)
+{
+	struct mptcp_pm_addr_entry *entry;
+	bool backup = false;
+
+	spin_lock_bh(&msk->pm.lock);
+	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
+		if (mptcp_addresses_equal(&entry->addr, skc, false)) {
+			backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+			break;
+		}
+	}
+	spin_unlock_bh(&msk->pm.lock);
+
+	return backup;
+}
+
 int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index b8b25124e7de..60c6b073d65f 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1109,6 +1109,9 @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
+bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb);
 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index be406197b1c4..0e4b5bfbeaa1 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -100,6 +100,7 @@ static struct mptcp_sock *subflow_token_join_request(struct request_sock *req)
 		return NULL;
 	}
 	subflow_req->local_id = local_id;
+	subflow_req->request_bkup = mptcp_pm_is_backup(msk, (struct sock_common *)req);
 
 	return msk;
 }
@@ -620,6 +621,8 @@ static int subflow_chk_local_id(struct sock *sk)
 		return err;
 
 	subflow_set_local_id(subflow, err);
+	subflow->request_bkup = mptcp_pm_is_backup(msk, (struct sock_common *)sk);
+
 	return 0;
 }
 

[PATCH 5.10.y 1/2] mptcp: export local_address

[Matthieu Baerts (NGI0)]

From: Geliang Tang <geliang.tang@suse.com>

commit dc886bce753cc2cf3c88ec5c7a6880a4e17d65ba upstream.

Rename local_address() with "mptcp_" prefix and export it in protocol.h.

This function will be re-used in the common PM code (pm.c) in the
following commit.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 6834097fc38c ("mptcp: pm: fix backup support in signal endpoints")
[ Conflicts in pm_netlink.c and protocol.h, because the context has
  changed in commit 4638de5aefe5 ("mptcp: handle local addrs announced
  by userspace PMs") which is not in this version. This commit is
  unrelated to this modification. Also some parts using 'local_address'
  are not in this version, that's OK, we don't need to do anything with
  them. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm_netlink.c | 9 ++++-----
 net/mptcp/protocol.h   | 1 +
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 7f4d84f5189b..6a0079d42dc4 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -84,8 +84,7 @@ static bool address_zero(const struct mptcp_addr_info *addr)
 	return addresses_equal(addr, &zero, false);
 }
 
-static void local_address(const struct sock_common *skc,
-			  struct mptcp_addr_info *addr)
+void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr)
 {
 	addr->port = 0;
 	addr->family = skc->skc_family;
@@ -120,7 +119,7 @@ static bool lookup_subflow_by_saddr(const struct list_head *list,
 	list_for_each_entry(subflow, list, node) {
 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 
-		local_address(skc, &cur);
+		mptcp_local_address(skc, &cur);
 		if (addresses_equal(&cur, saddr, false))
 			return true;
 	}
@@ -533,8 +532,8 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	/* The 0 ID mapping is defined by the first subflow, copied into the msk
 	 * addr
 	 */
-	local_address((struct sock_common *)msk, &msk_local);
-	local_address((struct sock_common *)skc, &skc_local);
+	mptcp_local_address((struct sock_common *)msk, &msk_local);
+	mptcp_local_address((struct sock_common *)skc, &skc_local);
 	if (addresses_equal(&msk_local, &skc_local, false))
 		return 0;
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index b5978bb4022f..ddfc7bde8c90 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -372,6 +372,7 @@ void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
 		       struct mptcp_subflow_context *subflow,
 		       long timeout);
 void mptcp_subflow_reset(struct sock *ssk);
+void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr);
 
 /* called with sk socket lock held */
 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
-- 
2.45.2

[PATCH 5.10.y 2/2] mptcp: pm: fix backup support in signal endpoints

[Matthieu Baerts (NGI0)]

commit 6834097fc38c5416701c793da94558cea49c0a1f upstream.

There was a support for signal endpoints, but only when the endpoint's
flag was changed during a connection. If an endpoint with the signal and
backup was already present, the MP_JOIN reply was not containing the
backup flag as expected.

That's confusing to have this inconsistent behaviour. On the other hand,
the infrastructure to set the backup flag in the SYN + ACK + MP_JOIN was
already there, it was just never set before. Now when requesting the
local ID from the path-manager, the backup status is also requested.

Note that when the userspace PM is used, the backup flag can be set if
the local address was already used before with a backup flag, e.g. if
the address was announced with the 'backup' flag, or a subflow was
created with the 'backup' flag.

Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/507
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Conflicts in pm_userspace.c because the context has changed in commit
  1e07938e29c5 ("net: mptcp: rename netlink handlers to
  mptcp_pm_nl_<blah>_{doit,dumpit}") which is not in this version. This
  commit is unrelated to this modification.
  Conflicts in protocol.h because the context has changed in commit
  9ae7846c4b6b ("mptcp: dump addrs in userspace pm list") which is not
  in this version. This commit is unrelated to this modification.
  Conflicts in pm.c because the context has changed in commit
  f40be0db0b76 ("mptcp: unify pm get_flags_and_ifindex_by_id") and
  commit 71b7dec27f34 ("mptcp: less aggressive retransmission strategy")
  which are not in this version. These commits are unrelated to this
  modification.
  Conflicts in subflow.c, because the commit 4cf86ae84c71 ("mptcp:
  strict local address ID selection") is not in this version. It is then
  not needed to modify the subflow_chk_local_id() helper, which is not
  in this version.
  Also, in this version, there is no pm_userspace.c, because this PM has
  been added in v5.19, which also causes conflicts in protocol.h, and
  pm_netlink.c. Plus the code in pm.c can be simplified, as there is no
  userspace PM. And the code in pm_netlink.c needs to use
  addresses_equal() instead of mptcp_addresses_equal(), see commit
  4638de5aefe5 ("mptcp: handle local addrs announced by userspace PMs").
  The code in pm_netlink.c also needs to be adapted because the
  pm_nl_get_pernet_from_msk() helper is not in this version, introduced
  later in commit c682bf536cf4 ("mptcp: add pm_nl_pernet helpers"), and
  also because the 'flags' are in mptcp_addr_info structure, see commit
  daa83ab03954 ("mptcp: move flags and ifindex out of
  mptcp_addr_info"). ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm.c         |  9 +++++++++
 net/mptcp/pm_netlink.c | 20 ++++++++++++++++++++
 net/mptcp/protocol.h   |  2 ++
 net/mptcp/subflow.c    |  1 +
 4 files changed, 32 insertions(+)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index e19e1525ecbb..1f310abbf1ed 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -225,6 +225,15 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	return mptcp_pm_nl_get_local_id(msk, skc);
 }
 
+bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
+{
+	struct mptcp_addr_info skc_local;
+
+	mptcp_local_address((struct sock_common *)skc, &skc_local);
+
+	return mptcp_pm_nl_is_backup(msk, &skc_local);
+}
+
 void mptcp_pm_data_init(struct mptcp_sock *msk)
 {
 	msk->pm.add_addr_signaled = 0;
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 6a0079d42dc4..ca57d856d5df 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -568,6 +568,26 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	return ret;
 }
 
+bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
+{
+	struct mptcp_pm_addr_entry *entry;
+	struct pm_nl_pernet *pernet;
+	bool backup = false;
+
+	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
+		if (addresses_equal(&entry->addr, skc, entry->addr.port)) {
+			backup = !!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	return backup;
+}
+
 void mptcp_pm_nl_data_init(struct mptcp_sock *msk)
 {
 	struct mptcp_pm_data *pm = &msk->pm;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index ddfc7bde8c90..4348bccb982f 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -481,6 +481,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			     u8 *rm_id);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
+bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
 
 void __init mptcp_pm_nl_init(void);
 void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
@@ -490,6 +491,7 @@ void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
 void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk);
 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id);
 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
+bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 
 static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
 {
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index f4067484727e..ba86cb06d6d8 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -80,6 +80,7 @@ static struct mptcp_sock *subflow_token_join_request(struct request_sock *req,
 		return NULL;
 	}
 	subflow_req->local_id = local_id;
+	subflow_req->request_bkup = mptcp_pm_is_backup(msk, (struct sock_common *)req);
 
 	get_random_bytes(&subflow_req->local_nonce, sizeof(u32));
 
-- 
2.45.2

Re: [PATCH 5.10.y 1/2] mptcp: export local_address

[Greg KH]

On Fri, Aug 09, 2024 at 12:55:39PM +0200, Matthieu Baerts (NGI0) wrote:
> From: Geliang Tang <geliang.tang@suse.com>
> 
> commit dc886bce753cc2cf3c88ec5c7a6880a4e17d65ba upstream.
> 
> Rename local_address() with "mptcp_" prefix and export it in protocol.h.
> 
> This function will be re-used in the common PM code (pm.c) in the
> following commit.
> 
> Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> Stable-dep-of: 6834097fc38c ("mptcp: pm: fix backup support in signal endpoints")
> [ Conflicts in pm_netlink.c and protocol.h, because the context has
>   changed in commit 4638de5aefe5 ("mptcp: handle local addrs announced
>   by userspace PMs") which is not in this version. This commit is
>   unrelated to this modification. Also some parts using 'local_address'
>   are not in this version, that's OK, we don't need to do anything with
>   them. ]
> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

All backports now queued up, thanks!

greg k-h