| Message ID | 20240726-mptcp-pm-avail-v5-5-fb1117ddeef6@kernel.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Commit | fdf749c7585ae8f745d4a8d7de82f84387a9bc78 |
| Delegated to: | Matthieu Baerts |
| Headers | show |
| Series | mptcp: fix endpoints with 'signal' and 'subflow' flags | expand |
| Context | Check | Description |
|---|---|---|
| matttbe/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 20 lines checked |
| matttbe/shellcheck | success | MPTCP selftests files have not been modified |
| matttbe/build | success | Build and static analysis OK |
| matttbe/KVM_Validation__normal | success | Success! ✅ |
| matttbe/KVM_Validation__debug | success | Success! ✅ |
| matttbe/KVM_Validation__btf__only_bpftest_all_ | success | Success! ✅ |
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 3ea417b52ff4..061fa3183eca 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -829,7 +829,7 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, 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); } @@ -843,7 +843,11 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, 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); }
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") Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> --- net/mptcp/pm_netlink.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)