From: Mat Martineau <martin...@kernel.org>

When path manager entries are deleted from the local address list, they
are first unlinked from the address list using list_del_rcu(). The
entries must not be freed until after the RCU grace period, but the
existing code immediately frees the entry.

Use kfree_rcu_mightsleep() and adjust sk_omem_alloc in open code instead
of using the sock_kfree_s() helper. This code path is only called in a
netlink handler, so the "might sleep" function is preferable to adding
a rarely-used rcu_head member to struct mptcp_pm_addr_entry.

Fixes: 88d097316371 ("mptcp: drop free_list for deleting entries")
Cc: sta...@vger.kernel.org
Signed-off-by: Mat Martineau <martin...@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matt...@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matt...@kernel.org>
---
 net/mptcp/pm_userspace.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 
2cb62f026b1f4420c549ab8ee6f54ffe3880d453..a715dcbe0146ed0c055d071c63257047a90a9afd
 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -337,7 +337,11 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct 
genl_info *info)
 
        release_sock(sk);
 
-       sock_kfree_s(sk, match, sizeof(*match));
+       kfree_rcu_mightsleep(match);
+       /* Adjust sk_omem_alloc like sock_kfree_s() does, to match
+        * with allocation of this memory by sock_kmemdup()
+        */
+       atomic_sub(sizeof(*match), &sk->sk_omem_alloc);
 
        err = 0;
 out:

-- 
2.48.1


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