6.6-stable review patch. If anyone has any objections, please let me know.
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From: Matthieu Baerts (NGI0) matttbe@kernel.org
commit 57f86203b41c98b322119dfdbb1ec54ce5e3369b upstream.
The ADD_ADDR 0 with the address from the initial subflow should not be considered as a new address: this is not something new. If the host receives it, it simply means that the address is available again.
When receiving an ADD_ADDR for the ID 0, the PM already doesn't consider it as new by not incrementing the 'add_addr_accepted' counter. But the 'accept_addr' might not be set if the limit has already been reached: this can be bypassed in this case. But before, it is important to check that this ADD_ADDR for the ID 0 is for the same address as the initial subflow. If not, it is not something that should happen, and the ADD_ADDR can be ignored.
Note that if an ADD_ADDR is received while there is already a subflow opened using the same address, this ADD_ADDR is ignored as well. It means that if multiple ADD_ADDR for ID 0 are received, there will not be any duplicated subflows created by the client.
Fixes: d0876b2284cf ("mptcp: add the incoming RM_ADDR support") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/mptcp/pm.c | 4 +++- net/mptcp/pm_netlink.c | 9 +++++++++ net/mptcp/protocol.h | 2 ++ 3 files changed, 14 insertions(+), 1 deletion(-)
--- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -227,7 +227,9 @@ void mptcp_pm_add_addr_received(const st } else { __MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP); } - } else if (!READ_ONCE(pm->accept_addr)) { + /* id0 should not have a different address */ + } else if ((addr->id == 0 && !mptcp_pm_nl_is_init_remote_addr(msk, addr)) || + (addr->id > 0 && !READ_ONCE(pm->accept_addr))) { mptcp_pm_announce_addr(msk, addr, true); mptcp_pm_add_addr_send_ack(msk); } else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) { --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -768,6 +768,15 @@ static void mptcp_pm_nl_add_addr_receive } }
+bool mptcp_pm_nl_is_init_remote_addr(struct mptcp_sock *msk, + const struct mptcp_addr_info *remote) +{ + struct mptcp_addr_info mpc_remote; + + remote_address((struct sock_common *)msk, &mpc_remote); + return mptcp_addresses_equal(&mpc_remote, remote, remote->port); +} + void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk) { struct mptcp_subflow_context *subflow; --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -907,6 +907,8 @@ void mptcp_pm_add_addr_received(const st void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk, const struct mptcp_addr_info *addr); void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk); +bool mptcp_pm_nl_is_init_remote_addr(struct mptcp_sock *msk, + const struct mptcp_addr_info *remote); void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk); void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);