This is a note to let you know that I've just added the patch titled mptcp: put subflow sock on connect error to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mptcp-put-subflow-sock-on-connect-error.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b3cc8605c6bacaef72b8f38f2bd2cfe82b9d2c85 Author: Florian Westphal <fw@xxxxxxxxx> Date: Thu Mar 4 13:32:09 2021 -0800 mptcp: put subflow sock on connect error [ Upstream commit f07157792c633b528de5fc1dbe2e4ea54f8e09d4 ] mptcp_add_pending_subflow() performs a sock_hold() on the subflow, then adds the subflow to the join list. Without a sock_put the subflow sk won't be freed in case connect() fails. unreferenced object 0xffff88810c03b100 (size 3000): [..] sk_prot_alloc.isra.0+0x2f/0x110 sk_alloc+0x5d/0xc20 inet6_create+0x2b7/0xd30 __sock_create+0x17f/0x410 mptcp_subflow_create_socket+0xff/0x9c0 __mptcp_subflow_connect+0x1da/0xaf0 mptcp_pm_nl_work+0x6e0/0x1120 mptcp_worker+0x508/0x9a0 Fixes: 5b950ff4331ddda ("mptcp: link MPC subflow into msk only after accept") Signed-off-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 16adba172fb9..591546d0953f 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1133,6 +1133,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, spin_lock_bh(&msk->join_list_lock); list_add_tail(&subflow->node, &msk->join_list); spin_unlock_bh(&msk->join_list_lock); + sock_put(mptcp_subflow_tcp_sock(subflow)); return err;