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(a)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 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122947-clapping-zookeeper-5d32@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:15 +0100
Subject: [PATCH] selftests: mptcp: pm: ensure unknown flags are ignored
This validates the previous commit: the userspace can set unknown flags
-- the 7th bit is currently unused -- without errors, but only the
supported ones are printed in the endpoints dumps.
The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-2-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/tools/testing/selftests/net/mptcp/pm_netlink.sh b/tools/testing/selftests/net/mptcp/pm_netlink.sh
index ec6a87588191..123d9d7a0278 100755
--- a/tools/testing/selftests/net/mptcp/pm_netlink.sh
+++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh
@@ -192,6 +192,10 @@ check "show_endpoints" \
flush_endpoint
check "show_endpoints" "" "flush addrs"
+add_endpoint 10.0.1.1 flags unknown
+check "show_endpoints" "$(format_endpoints "1,10.0.1.1")" "ignore unknown flags"
+flush_endpoint
+
set_limits 9 1 2>/dev/null
check "get_limits" "${default_limits}" "rcv addrs above hard limit"
diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
index 65b374232ff5..99eecccbf0c8 100644
--- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
+++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
@@ -24,6 +24,8 @@
#define IPPROTO_MPTCP 262
#endif
+#define MPTCP_PM_ADDR_FLAG_UNKNOWN _BITUL(7)
+
static void syntax(char *argv[])
{
fprintf(stderr, "%s add|ann|rem|csf|dsf|get|set|del|flush|dump|events|listen|accept [<args>]\n", argv[0]);
@@ -836,6 +838,8 @@ int add_addr(int fd, int pm_family, int argc, char *argv[])
flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
else if (!strcmp(tok, "fullmesh"))
flags |= MPTCP_PM_ADDR_FLAG_FULLMESH;
+ else if (!strcmp(tok, "unknown"))
+ flags |= MPTCP_PM_ADDR_FLAG_UNKNOWN;
else
error(1, errno,
"unknown flag %s", argv[arg]);
@@ -1048,6 +1052,13 @@ static void print_addr(struct rtattr *attrs, int len)
printf(",");
}
+ if (flags & MPTCP_PM_ADDR_FLAG_UNKNOWN) {
+ printf("unknown");
+ flags &= ~MPTCP_PM_ADDR_FLAG_UNKNOWN;
+ if (flags)
+ printf(",");
+ }
+
/* bump unknown flags, if any */
if (flags)
printf("0x%x", flags);
The patch below does not apply to the 6.6-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(a)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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122946-puppet-visiting-41e4@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:15 +0100
Subject: [PATCH] selftests: mptcp: pm: ensure unknown flags are ignored
This validates the previous commit: the userspace can set unknown flags
-- the 7th bit is currently unused -- without errors, but only the
supported ones are printed in the endpoints dumps.
The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-2-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/tools/testing/selftests/net/mptcp/pm_netlink.sh b/tools/testing/selftests/net/mptcp/pm_netlink.sh
index ec6a87588191..123d9d7a0278 100755
--- a/tools/testing/selftests/net/mptcp/pm_netlink.sh
+++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh
@@ -192,6 +192,10 @@ check "show_endpoints" \
flush_endpoint
check "show_endpoints" "" "flush addrs"
+add_endpoint 10.0.1.1 flags unknown
+check "show_endpoints" "$(format_endpoints "1,10.0.1.1")" "ignore unknown flags"
+flush_endpoint
+
set_limits 9 1 2>/dev/null
check "get_limits" "${default_limits}" "rcv addrs above hard limit"
diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
index 65b374232ff5..99eecccbf0c8 100644
--- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
+++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
@@ -24,6 +24,8 @@
#define IPPROTO_MPTCP 262
#endif
+#define MPTCP_PM_ADDR_FLAG_UNKNOWN _BITUL(7)
+
static void syntax(char *argv[])
{
fprintf(stderr, "%s add|ann|rem|csf|dsf|get|set|del|flush|dump|events|listen|accept [<args>]\n", argv[0]);
@@ -836,6 +838,8 @@ int add_addr(int fd, int pm_family, int argc, char *argv[])
flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
else if (!strcmp(tok, "fullmesh"))
flags |= MPTCP_PM_ADDR_FLAG_FULLMESH;
+ else if (!strcmp(tok, "unknown"))
+ flags |= MPTCP_PM_ADDR_FLAG_UNKNOWN;
else
error(1, errno,
"unknown flag %s", argv[arg]);
@@ -1048,6 +1052,13 @@ static void print_addr(struct rtattr *attrs, int len)
printf(",");
}
+ if (flags & MPTCP_PM_ADDR_FLAG_UNKNOWN) {
+ printf("unknown");
+ flags &= ~MPTCP_PM_ADDR_FLAG_UNKNOWN;
+ if (flags)
+ printf(",");
+ }
+
/* bump unknown flags, if any */
if (flags)
printf("0x%x", flags);
The patch below does not apply to the 6.1-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(a)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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122946-wharf-satin-c518@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:15 +0100
Subject: [PATCH] selftests: mptcp: pm: ensure unknown flags are ignored
This validates the previous commit: the userspace can set unknown flags
-- the 7th bit is currently unused -- without errors, but only the
supported ones are printed in the endpoints dumps.
The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-2-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/tools/testing/selftests/net/mptcp/pm_netlink.sh b/tools/testing/selftests/net/mptcp/pm_netlink.sh
index ec6a87588191..123d9d7a0278 100755
--- a/tools/testing/selftests/net/mptcp/pm_netlink.sh
+++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh
@@ -192,6 +192,10 @@ check "show_endpoints" \
flush_endpoint
check "show_endpoints" "" "flush addrs"
+add_endpoint 10.0.1.1 flags unknown
+check "show_endpoints" "$(format_endpoints "1,10.0.1.1")" "ignore unknown flags"
+flush_endpoint
+
set_limits 9 1 2>/dev/null
check "get_limits" "${default_limits}" "rcv addrs above hard limit"
diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
index 65b374232ff5..99eecccbf0c8 100644
--- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
+++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
@@ -24,6 +24,8 @@
#define IPPROTO_MPTCP 262
#endif
+#define MPTCP_PM_ADDR_FLAG_UNKNOWN _BITUL(7)
+
static void syntax(char *argv[])
{
fprintf(stderr, "%s add|ann|rem|csf|dsf|get|set|del|flush|dump|events|listen|accept [<args>]\n", argv[0]);
@@ -836,6 +838,8 @@ int add_addr(int fd, int pm_family, int argc, char *argv[])
flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
else if (!strcmp(tok, "fullmesh"))
flags |= MPTCP_PM_ADDR_FLAG_FULLMESH;
+ else if (!strcmp(tok, "unknown"))
+ flags |= MPTCP_PM_ADDR_FLAG_UNKNOWN;
else
error(1, errno,
"unknown flag %s", argv[arg]);
@@ -1048,6 +1052,13 @@ static void print_addr(struct rtattr *attrs, int len)
printf(",");
}
+ if (flags & MPTCP_PM_ADDR_FLAG_UNKNOWN) {
+ printf("unknown");
+ flags &= ~MPTCP_PM_ADDR_FLAG_UNKNOWN;
+ if (flags)
+ printf(",");
+ }
+
/* bump unknown flags, if any */
if (flags)
printf("0x%x", flags);
The patch below does not apply to the 6.12-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(a)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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122945-litigator-machinist-2f66@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:15 +0100
Subject: [PATCH] selftests: mptcp: pm: ensure unknown flags are ignored
This validates the previous commit: the userspace can set unknown flags
-- the 7th bit is currently unused -- without errors, but only the
supported ones are printed in the endpoints dumps.
The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-2-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/tools/testing/selftests/net/mptcp/pm_netlink.sh b/tools/testing/selftests/net/mptcp/pm_netlink.sh
index ec6a87588191..123d9d7a0278 100755
--- a/tools/testing/selftests/net/mptcp/pm_netlink.sh
+++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh
@@ -192,6 +192,10 @@ check "show_endpoints" \
flush_endpoint
check "show_endpoints" "" "flush addrs"
+add_endpoint 10.0.1.1 flags unknown
+check "show_endpoints" "$(format_endpoints "1,10.0.1.1")" "ignore unknown flags"
+flush_endpoint
+
set_limits 9 1 2>/dev/null
check "get_limits" "${default_limits}" "rcv addrs above hard limit"
diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
index 65b374232ff5..99eecccbf0c8 100644
--- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
+++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
@@ -24,6 +24,8 @@
#define IPPROTO_MPTCP 262
#endif
+#define MPTCP_PM_ADDR_FLAG_UNKNOWN _BITUL(7)
+
static void syntax(char *argv[])
{
fprintf(stderr, "%s add|ann|rem|csf|dsf|get|set|del|flush|dump|events|listen|accept [<args>]\n", argv[0]);
@@ -836,6 +838,8 @@ int add_addr(int fd, int pm_family, int argc, char *argv[])
flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
else if (!strcmp(tok, "fullmesh"))
flags |= MPTCP_PM_ADDR_FLAG_FULLMESH;
+ else if (!strcmp(tok, "unknown"))
+ flags |= MPTCP_PM_ADDR_FLAG_UNKNOWN;
else
error(1, errno,
"unknown flag %s", argv[arg]);
@@ -1048,6 +1052,13 @@ static void print_addr(struct rtattr *attrs, int len)
printf(",");
}
+ if (flags & MPTCP_PM_ADDR_FLAG_UNKNOWN) {
+ printf("unknown");
+ flags &= ~MPTCP_PM_ADDR_FLAG_UNKNOWN;
+ if (flags)
+ printf(",");
+ }
+
/* bump unknown flags, if any */
if (flags)
printf("0x%x", flags);
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(a)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 0ace3297a7301911e52d8195cb1006414897c859
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122924-retold-train-22bc@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0ace3297a7301911e52d8195cb1006414897c859 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:14 +0100
Subject: [PATCH] mptcp: pm: ignore unknown endpoint flags
Before this patch, the kernel was saving any flags set by the userspace,
even unknown ones. This doesn't cause critical issues because the kernel
is only looking at specific ones. But on the other hand, endpoints dumps
could tell the userspace some recent flags seem to be supported on older
kernel versions.
Instead, ignore all unknown flags when parsing them. By doing that, the
userspace can continue to set unsupported flags, but it has a way to
verify what is supported by the kernel.
Note that it sounds better to continue accepting unsupported flags not
to change the behaviour, but also that eases things on the userspace
side by adding "optional" endpoint types only supported by newer kernel
versions without having to deal with the different kernel versions.
A note for the backports: there will be conflicts in mptcp.h on older
versions not having the mentioned flags, the new line should still be
added last, and the '5' needs to be adapted to have the same value as
the last entry.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-1-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 04eea6d1d0a9..72a5d030154e 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -40,6 +40,7 @@
#define MPTCP_PM_ADDR_FLAG_FULLMESH _BITUL(3)
#define MPTCP_PM_ADDR_FLAG_IMPLICIT _BITUL(4)
#define MPTCP_PM_ADDR_FLAG_LAMINAR _BITUL(5)
+#define MPTCP_PM_ADDR_FLAGS_MASK GENMASK(5, 0)
struct mptcp_info {
__u8 mptcpi_subflows;
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index d5b383870f79..7aa42de9c47b 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -119,7 +119,8 @@ int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
}
if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
- entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
+ entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]) &
+ MPTCP_PM_ADDR_FLAGS_MASK;
if (tb[MPTCP_PM_ADDR_ATTR_PORT])
entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
The patch below does not apply to the 6.1-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(a)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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 0ace3297a7301911e52d8195cb1006414897c859
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122923-underhand-chalice-083b@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0ace3297a7301911e52d8195cb1006414897c859 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:14 +0100
Subject: [PATCH] mptcp: pm: ignore unknown endpoint flags
Before this patch, the kernel was saving any flags set by the userspace,
even unknown ones. This doesn't cause critical issues because the kernel
is only looking at specific ones. But on the other hand, endpoints dumps
could tell the userspace some recent flags seem to be supported on older
kernel versions.
Instead, ignore all unknown flags when parsing them. By doing that, the
userspace can continue to set unsupported flags, but it has a way to
verify what is supported by the kernel.
Note that it sounds better to continue accepting unsupported flags not
to change the behaviour, but also that eases things on the userspace
side by adding "optional" endpoint types only supported by newer kernel
versions without having to deal with the different kernel versions.
A note for the backports: there will be conflicts in mptcp.h on older
versions not having the mentioned flags, the new line should still be
added last, and the '5' needs to be adapted to have the same value as
the last entry.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-1-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 04eea6d1d0a9..72a5d030154e 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -40,6 +40,7 @@
#define MPTCP_PM_ADDR_FLAG_FULLMESH _BITUL(3)
#define MPTCP_PM_ADDR_FLAG_IMPLICIT _BITUL(4)
#define MPTCP_PM_ADDR_FLAG_LAMINAR _BITUL(5)
+#define MPTCP_PM_ADDR_FLAGS_MASK GENMASK(5, 0)
struct mptcp_info {
__u8 mptcpi_subflows;
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index d5b383870f79..7aa42de9c47b 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -119,7 +119,8 @@ int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
}
if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
- entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
+ entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]) &
+ MPTCP_PM_ADDR_FLAGS_MASK;
if (tb[MPTCP_PM_ADDR_ATTR_PORT])
entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
The patch below does not apply to the 5.15-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(a)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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 0ace3297a7301911e52d8195cb1006414897c859
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122923-crunchy-grapple-39a2@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0ace3297a7301911e52d8195cb1006414897c859 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:14 +0100
Subject: [PATCH] mptcp: pm: ignore unknown endpoint flags
Before this patch, the kernel was saving any flags set by the userspace,
even unknown ones. This doesn't cause critical issues because the kernel
is only looking at specific ones. But on the other hand, endpoints dumps
could tell the userspace some recent flags seem to be supported on older
kernel versions.
Instead, ignore all unknown flags when parsing them. By doing that, the
userspace can continue to set unsupported flags, but it has a way to
verify what is supported by the kernel.
Note that it sounds better to continue accepting unsupported flags not
to change the behaviour, but also that eases things on the userspace
side by adding "optional" endpoint types only supported by newer kernel
versions without having to deal with the different kernel versions.
A note for the backports: there will be conflicts in mptcp.h on older
versions not having the mentioned flags, the new line should still be
added last, and the '5' needs to be adapted to have the same value as
the last entry.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-1-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 04eea6d1d0a9..72a5d030154e 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -40,6 +40,7 @@
#define MPTCP_PM_ADDR_FLAG_FULLMESH _BITUL(3)
#define MPTCP_PM_ADDR_FLAG_IMPLICIT _BITUL(4)
#define MPTCP_PM_ADDR_FLAG_LAMINAR _BITUL(5)
+#define MPTCP_PM_ADDR_FLAGS_MASK GENMASK(5, 0)
struct mptcp_info {
__u8 mptcpi_subflows;
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index d5b383870f79..7aa42de9c47b 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -119,7 +119,8 @@ int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
}
if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
- entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
+ entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]) &
+ MPTCP_PM_ADDR_FLAGS_MASK;
if (tb[MPTCP_PM_ADDR_ATTR_PORT])
entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
The patch below does not apply to the 6.6-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(a)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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 0ace3297a7301911e52d8195cb1006414897c859
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122922-cedar-reapply-f9d1@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0ace3297a7301911e52d8195cb1006414897c859 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:14 +0100
Subject: [PATCH] mptcp: pm: ignore unknown endpoint flags
Before this patch, the kernel was saving any flags set by the userspace,
even unknown ones. This doesn't cause critical issues because the kernel
is only looking at specific ones. But on the other hand, endpoints dumps
could tell the userspace some recent flags seem to be supported on older
kernel versions.
Instead, ignore all unknown flags when parsing them. By doing that, the
userspace can continue to set unsupported flags, but it has a way to
verify what is supported by the kernel.
Note that it sounds better to continue accepting unsupported flags not
to change the behaviour, but also that eases things on the userspace
side by adding "optional" endpoint types only supported by newer kernel
versions without having to deal with the different kernel versions.
A note for the backports: there will be conflicts in mptcp.h on older
versions not having the mentioned flags, the new line should still be
added last, and the '5' needs to be adapted to have the same value as
the last entry.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-1-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 04eea6d1d0a9..72a5d030154e 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -40,6 +40,7 @@
#define MPTCP_PM_ADDR_FLAG_FULLMESH _BITUL(3)
#define MPTCP_PM_ADDR_FLAG_IMPLICIT _BITUL(4)
#define MPTCP_PM_ADDR_FLAG_LAMINAR _BITUL(5)
+#define MPTCP_PM_ADDR_FLAGS_MASK GENMASK(5, 0)
struct mptcp_info {
__u8 mptcpi_subflows;
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index d5b383870f79..7aa42de9c47b 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -119,7 +119,8 @@ int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
}
if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
- entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
+ entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]) &
+ MPTCP_PM_ADDR_FLAGS_MASK;
if (tb[MPTCP_PM_ADDR_ATTR_PORT])
entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
The patch below does not apply to the 6.12-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(a)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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 0ace3297a7301911e52d8195cb1006414897c859
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122921-regress-overhand-2900@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0ace3297a7301911e52d8195cb1006414897c859 Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Fri, 5 Dec 2025 19:55:14 +0100
Subject: [PATCH] mptcp: pm: ignore unknown endpoint flags
Before this patch, the kernel was saving any flags set by the userspace,
even unknown ones. This doesn't cause critical issues because the kernel
is only looking at specific ones. But on the other hand, endpoints dumps
could tell the userspace some recent flags seem to be supported on older
kernel versions.
Instead, ignore all unknown flags when parsing them. By doing that, the
userspace can continue to set unsupported flags, but it has a way to
verify what is supported by the kernel.
Note that it sounds better to continue accepting unsupported flags not
to change the behaviour, but also that eases things on the userspace
side by adding "optional" endpoint types only supported by newer kernel
versions without having to deal with the different kernel versions.
A note for the backports: there will be conflicts in mptcp.h on older
versions not having the mentioned flags, the new line should still be
added last, and the '5' needs to be adapted to have the same value as
the last entry.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-1-9e4781…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 04eea6d1d0a9..72a5d030154e 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -40,6 +40,7 @@
#define MPTCP_PM_ADDR_FLAG_FULLMESH _BITUL(3)
#define MPTCP_PM_ADDR_FLAG_IMPLICIT _BITUL(4)
#define MPTCP_PM_ADDR_FLAG_LAMINAR _BITUL(5)
+#define MPTCP_PM_ADDR_FLAGS_MASK GENMASK(5, 0)
struct mptcp_info {
__u8 mptcpi_subflows;
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index d5b383870f79..7aa42de9c47b 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -119,7 +119,8 @@ int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
}
if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
- entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
+ entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]) &
+ MPTCP_PM_ADDR_FLAGS_MASK;
if (tb[MPTCP_PM_ADDR_ATTR_PORT])
entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));