[PATCH 6.6 195/299] mptcp: fix data races on remote_id

Greg Kroah-Hartman
2024-02-27T13:55:43Z

From: Paolo Abeni <pabeni@redhat.com>

commit 967d3c27127e71a10ff5c083583a038606431b61 upstream.

Similar to the previous patch, address the data race on
remote_id, adding the suitable ONCE annotations.

Fixes: bedee0b56113 ("mptcp: address lookup improvements")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/mptcp/pm_netlink.c | 8 ++++----
net/mptcp/subflow.c | 6 +++---
2 files changed, 7 insertions(+), 7 deletions(-)

--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -443,7 +443,7 @@ static unsigned int fill_remote_addresse
mptcp_for_each_subflow(msk, subflow) {
ssk = mptcp_subflow_tcp_sock(subflow);
remote_address((struct sock_common *)ssk, &addrs[i]);
- addrs[i].id = subflow->remote_id;
+ addrs[i].id = READ_ONCE(subflow->remote_id);
if (deny_id0 && !addrs[i].id)
continue;

@@ -799,18 +799,18 @@ static void mptcp_pm_nl_rm_addr_or_subfl

mptcp_for_each_subflow_safe(msk, subflow, tmp) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+ u8 remote_id = READ_ONCE(subflow->remote_id);
int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
u8 id = subflow_get_local_id(subflow);

- if (rm_type == MPTCP_MIB_RMADDR && subflow->remote_id != rm_id)
+ if (rm_type == MPTCP_MIB_RMADDR && remote_id != rm_id)
continue;
if (rm_type == MPTCP_MIB_RMSUBFLOW && !mptcp_local_id_match(msk, id, rm_id))
continue;

pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u",
rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
- i, rm_id, id, subflow->remote_id,
- msk->mpc_endpoint_id);
+ i, rm_id, id, remote_id, msk->mpc_endpoint_id);
spin_unlock_bh(&msk->pm.lock);
mptcp_subflow_shutdown(sk, ssk, how);

--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -535,7 +535,7 @@ static void subflow_finish_connect(struc
subflow->backup = mp_opt.backup;
subflow->thmac = mp_opt.thmac;
subflow->remote_nonce = mp_opt.nonce;
- subflow->remote_id = mp_opt.join_id;
+ WRITE_ONCE(subflow->remote_id, mp_opt.join_id);
pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u backup=%d",
subflow, subflow->thmac, subflow->remote_nonce,
subflow->backup);
@@ -1561,7 +1561,7 @@ int __mptcp_subflow_connect(struct sock
pr_debug("msk=%p remote_token=%u local_id=%d remote_id=%d", msk,
remote_token, local_id, remote_id);
subflow->remote_token = remote_token;
- subflow->remote_id = remote_id;
+ WRITE_ONCE(subflow->remote_id, remote_id);
subflow->request_join = 1;
subflow->request_bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP);
subflow->subflow_id = msk->subflow_id++;
@@ -1966,7 +1966,7 @@ static void subflow_ulp_clone(const stru
new_ctx->fully_established = 1;
new_ctx->remote_key_valid = 1;
new_ctx->backup = subflow_req->backup;
- new_ctx->remote_id = subflow_req->remote_id;
+ WRITE_ONCE(new_ctx->remote_id, subflow_req->remote_id);
new_ctx->token = subflow_req->token;
new_ctx->thmac = subflow_req->thmac;