6.6-stable review patch. If anyone has any objections, please let me know.
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From: YonglongLi liyonglong@chinatelecom.cn
commit 40eec1795cc27b076d49236649a29507c7ed8c2d upstream.
The creation of new subflows can fail for different reasons. If no subflow have been created using the received ADD_ADDR, the related counters should not be updated, otherwise they will never be decremented for events related to this ID later on.
For the moment, the number of accepted ADD_ADDR is only decremented upon the reception of a related RM_ADDR, and only if the remote address ID is currently being used by at least one subflow. In other words, if no subflow can be created with the received address, the counter will not be decremented. In this case, it is then important not to increment pm.add_addr_accepted counter, and not to modify pm.accept_addr bit.
Note that this patch does not modify the behaviour in case of failures later on, e.g. if the MP Join is dropped or rejected.
The "remove invalid addresses" MP Join subtest has been modified to validate this case. The broadcast IP address is added before the "valid" address that will be used to successfully create a subflow, and the limit is decreased by one: without this patch, it was not possible to create the last subflow, because:
- the broadcast address would have been accepted even if it was not usable: the creation of a subflow to this address results in an error,
- the limit of 2 accepted ADD_ADDR would have then been reached.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM") Cc: stable@vger.kernel.org Co-developed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: YonglongLi liyonglong@chinatelecom.cn Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Link: https://lore.kernel.org/r/20240607-upstream-net-20240607-misc-fixes-v1-3-1ab... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/mptcp/pm_netlink.c | 16 ++++++++++------ tools/testing/selftests/net/mptcp/mptcp_join.sh | 4 ++-- 2 files changed, 12 insertions(+), 8 deletions(-)
--- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -685,6 +685,7 @@ static void mptcp_pm_nl_add_addr_receive unsigned int add_addr_accept_max; struct mptcp_addr_info remote; unsigned int subflows_max; + bool sf_created = false; int i, nr;
add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk); @@ -712,15 +713,18 @@ static void mptcp_pm_nl_add_addr_receive if (nr == 0) return;
- msk->pm.add_addr_accepted++; - if (msk->pm.add_addr_accepted >= add_addr_accept_max || - msk->pm.subflows >= subflows_max) - WRITE_ONCE(msk->pm.accept_addr, false); - spin_unlock_bh(&msk->pm.lock); for (i = 0; i < nr; i++) - __mptcp_subflow_connect(sk, &addrs[i], &remote); + if (__mptcp_subflow_connect(sk, &addrs[i], &remote) == 0) + sf_created = true; spin_lock_bh(&msk->pm.lock); + + if (sf_created) { + msk->pm.add_addr_accepted++; + if (msk->pm.add_addr_accepted >= add_addr_accept_max || + msk->pm.subflows >= subflows_max) + WRITE_ONCE(msk->pm.accept_addr, false); + } }
void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk) --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -2393,10 +2393,10 @@ remove_tests() if reset "remove invalid addresses"; then pm_nl_set_limits $ns1 3 3 pm_nl_add_endpoint $ns1 10.0.12.1 flags signal - pm_nl_add_endpoint $ns1 10.0.3.1 flags signal # broadcast IP: no packet for this address will be received on ns1 pm_nl_add_endpoint $ns1 224.0.0.1 flags signal - pm_nl_set_limits $ns2 3 3 + pm_nl_add_endpoint $ns1 10.0.3.1 flags signal + pm_nl_set_limits $ns2 2 2 addr_nr_ns1=-3 speed=10 \ run_tests $ns1 $ns2 10.0.1.1 chk_join_nr 1 1 1