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authorMat Martineau <mathew.j.martineau@linux.intel.com>2022-07-05 14:32:13 -0700
committerDavid S. Miller <davem@davemloft.net>2022-07-06 12:50:26 +0100
commita657430260e5437df16004c8c317821d946b5ead (patch)
tree4fe7f7f89d45858bfad5f4de76d823dc526125bd
parentc21b50d5912b68c4414c60ef5b30416c103f9fd8 (diff)
mptcp: Acquire the subflow socket lock before modifying MP_PRIO flags
When setting up a subflow's flags for sending MP_PRIO MPTCP options, the subflow socket lock was not held while reading and modifying several struct members that are also read and modified in mptcp_write_options(). Acquire the subflow socket lock earlier and send the MP_PRIO ACK with that lock already acquired. Add a new variant of the mptcp_subflow_send_ack() helper to use with the subflow lock held. Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support") Acked-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>
-rw-r--r--net/mptcp/pm_netlink.c5
-rw-r--r--net/mptcp/protocol.c9
-rw-r--r--net/mptcp/protocol.h1
3 files changed, 12 insertions, 3 deletions
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 5ff93b73f33d..ca86c88f89e0 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -728,11 +728,13 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
mptcp_for_each_subflow(msk, subflow) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
struct mptcp_addr_info local;
+ bool slow;
local_address((struct sock_common *)ssk, &local);
if (!mptcp_addresses_equal(&local, addr, addr->port))
continue;
+ slow = lock_sock_fast(ssk);
if (subflow->backup != bkup)
msk->last_snd = NULL;
subflow->backup = bkup;
@@ -740,7 +742,8 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
subflow->request_bkup = bkup;
pr_debug("send ack for mp_prio");
- mptcp_subflow_send_ack(ssk);
+ __mptcp_subflow_send_ack(ssk);
+ unlock_sock_fast(ssk, slow);
return 0;
}
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index e475212f2618..cc21fafd9726 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -506,13 +506,18 @@ static inline bool tcp_can_send_ack(const struct sock *ssk)
(TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN));
}
+void __mptcp_subflow_send_ack(struct sock *ssk)
+{
+ if (tcp_can_send_ack(ssk))
+ tcp_send_ack(ssk);
+}
+
void mptcp_subflow_send_ack(struct sock *ssk)
{
bool slow;
slow = lock_sock_fast(ssk);
- if (tcp_can_send_ack(ssk))
- tcp_send_ack(ssk);
+ __mptcp_subflow_send_ack(ssk);
unlock_sock_fast(ssk, slow);
}
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index c14d70c036d0..033c995772dc 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -607,6 +607,7 @@ void __init mptcp_subflow_init(void);
void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
struct mptcp_subflow_context *subflow);
+void __mptcp_subflow_send_ack(struct sock *ssk);
void mptcp_subflow_send_ack(struct sock *ssk);
void mptcp_subflow_reset(struct sock *ssk);
void mptcp_subflow_queue_clean(struct sock *ssk);