diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2022-02-18 13:35:41 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-02-19 12:28:00 +0000 |
| commit | 837cf45df163a3780bc04b555700231e95b31dc9 (patch) | |
| tree | f059a95f02bfad5cb1929eda0a3e26f0aca1bb94 /net/mptcp | |
| parent | 98247bc16a27cf8ead4c47ce9f15888be85841fc (diff) | |
| download | linux-837cf45df163a3780bc04b555700231e95b31dc9.tar.bz2 | |
mptcp: fix race in incoming ADD_ADDR option processing
If an MPTCP endpoint received multiple consecutive incoming
ADD_ADDR options, mptcp_pm_add_addr_received() can overwrite
the current remote address value after the PM lock is released
in mptcp_pm_nl_add_addr_received() and before such address
is echoed.
Fix the issue caching the remote address value a little earlier
and always using the cached value after releasing the PM lock.
Fixes: f7efc7771eac ("mptcp: drop argument port from mptcp_pm_announce_addr")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
| -rw-r--r-- | net/mptcp/pm_netlink.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 82f82a513f5b..4b5d795383cd 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -660,6 +660,7 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) unsigned int add_addr_accept_max; struct mptcp_addr_info remote; unsigned int subflows_max; + bool reset_port = false; int i, nr; add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk); @@ -669,15 +670,19 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) msk->pm.add_addr_accepted, add_addr_accept_max, msk->pm.remote.family); - if (lookup_subflow_by_daddr(&msk->conn_list, &msk->pm.remote)) + remote = msk->pm.remote; + if (lookup_subflow_by_daddr(&msk->conn_list, &remote)) goto add_addr_echo; + /* pick id 0 port, if none is provided the remote address */ + if (!remote.port) { + reset_port = true; + remote.port = sk->sk_dport; + } + /* connect to the specified remote address, using whatever * local address the routing configuration will pick. */ - remote = msk->pm.remote; - if (!remote.port) - remote.port = sk->sk_dport; nr = fill_local_addresses_vec(msk, addrs); msk->pm.add_addr_accepted++; @@ -690,8 +695,12 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) __mptcp_subflow_connect(sk, &addrs[i], &remote); spin_lock_bh(&msk->pm.lock); + /* be sure to echo exactly the received address */ + if (reset_port) + remote.port = 0; + add_addr_echo: - mptcp_pm_announce_addr(msk, &msk->pm.remote, true); + mptcp_pm_announce_addr(msk, &remote, true); mptcp_pm_nl_addr_send_ack(msk); } |