mptcp: pm: only decrement add_addr_accepted for MPJ req

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>

commit 1c1f721375989579e46741f59523e39ec9b2a9bd upstream.

Adding the following warning ...

  WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)

... before decrementing the add_addr_accepted counter helped to find a
bug when running the "remove single subflow" subtest from the
mptcp_join.sh selftest.

Removing a 'subflow' endpoint will first trigger a RM_ADDR, then the
subflow closure. Before this patch, and upon the reception of the
RM_ADDR, the other peer will then try to decrement this
add_addr_accepted. That's not correct because the attached subflows have
not been created upon the reception of an ADD_ADDR.

A way to solve that is to decrement the counter only if the attached
subflow was an MP_JOIN to a remote id that was not 0, and initiated by
the host receiving the RM_ADDR.

Fixes: d0876b2284cf ("mptcp: add the incoming RM_ADDR support")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
Link: https://patch.msgid.link/20240819-net-mptcp-pm-reusing-id-v1-9-38035d40de5b@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/mptcp/pm_netlink.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -834,7 +834,7 @@ static void mptcp_pm_nl_rm_addr_or_subfl
 			mptcp_close_ssk(sk, ssk, subflow);
 			spin_lock_bh(&msk->pm.lock);
 
-			removed = true;
+			removed |= subflow->request_join;
 			if (rm_type == MPTCP_MIB_RMSUBFLOW)
 				__MPTCP_INC_STATS(sock_net(sk), rm_type);
 		}
@@ -848,7 +848,11 @@ static void mptcp_pm_nl_rm_addr_or_subfl
 		if (!mptcp_pm_is_kernel(msk))
 			continue;
 
-		if (rm_type == MPTCP_MIB_RMADDR) {
+		if (rm_type == MPTCP_MIB_RMADDR && rm_id &&
+		    !WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)) {
+			/* Note: if the subflow has been closed before, this
+			 * add_addr_accepted counter will not be decremented.
+			 */
 			msk->pm.add_addr_accepted--;
 			WRITE_ONCE(msk->pm.accept_addr, true);
 		} else if (rm_type == MPTCP_MIB_RMSUBFLOW) {


Patches currently in stable-queue which might be from matttbe@xxxxxxxxxx are

queue-6.1/mptcp-pm-only-decrement-add_addr_accepted-for-mpj-req.patch
queue-6.1/mptcp-pm-re-using-id-of-unused-flushed-subflows.patch
queue-6.1/mptcp-pm-re-using-id-of-unused-removed-add_addr.patch
queue-6.1/mptcp-pm-re-using-id-of-unused-removed-subflows.patch
queue-6.1/mptcp-correct-mptcp_subflow_attr_ssn_offset-reserved.patch




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux