[PATCH net-next 3/5] mptcp: pm: in-kernel: avoid access entry without lock

From: Matthieu Baerts (NGI0)
Date: Fri Feb 28 2025 - 09:40:18 EST


From: Geliang Tang <tanggeliang@xxxxxxxxxx>

In mptcp_pm_nl_set_flags(), "entry" is copied to "local" when pernet->lock
is held to avoid direct access to entry without pernet->lock.

Therefore, "local->flags" should be passed to mptcp_nl_set_flags instead
of "entry->flags" when pernet->lock is not held, so as to avoid access to
entry.

Signed-off-by: Geliang Tang <tanggeliang@xxxxxxxxxx>
Fixes: 145dc6cc4abd ("mptcp: pm: change to fullmesh only for 'subflow'")
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
---
net/mptcp/pm_netlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index d4328443d844dbe52d2b0cc0018dcac1e4245320..fb83eba041f17c09923a8ed1a033983692962c5a 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1983,7 +1983,7 @@ int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
*local = *entry;
spin_unlock_bh(&pernet->lock);

- mptcp_nl_set_flags(net, &local->addr, entry->flags, changed);
+ mptcp_nl_set_flags(net, &local->addr, local->flags, changed);
return 0;
}


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2.47.1