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 [ Conflicts in pm.c, due to commit 4d25247d3ae4 ("mptcp: bypass in-kernel PM restrictions for non-kernel PMs"), which is not in this version, and changes the context. The same fix can be applied here by adding the new check at the same place. Note that addresses_equal() has been used instead of mptcp_addresses_equal(), renamed in commit 4638de5aefe5 ("mptcp: handle local addrs announced by userspace PMs"), not in this version. ] Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/pm.c | 4 +++- net/mptcp/pm_netlink.c | 9 +++++++++ net/mptcp/protocol.h | 2 ++ 3 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index d9111efa3c7f..b14eb6bccd36 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -189,7 +189,9 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
spin_lock_bh(&pm->lock);
- if (!READ_ONCE(pm->accept_addr)) { + /* id0 should not have a different address */ + 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)) { diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 6df7d62f6b44..932be4bc1274 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -672,6 +672,15 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) mptcp_pm_nl_addr_send_ack(msk); }
+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 addresses_equal(&mpc_remote, remote, remote->port); +} + void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk) { struct mptcp_subflow_context *subflow; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index d940a059a8f3..9e0a5591d4e1 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -742,6 +742,8 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk, 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);