rxrpc: Don't transmit an ACK if there's no reason set

Don't transmit an ACK if call->ackr_reason in unset.  There's the
possibility of a race between recvmsg() sending an ACK and the background
processing thread trying to send the same one.

Signed-off-by: David Howells <dhowells@redhat.com>
This commit is contained in:
David Howells 2016-09-17 10:49:13 +01:00
parent dfa7d92040
commit 27d0fc431c

View File

@ -137,6 +137,11 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
switch (type) {
case RXRPC_PACKET_TYPE_ACK:
spin_lock_bh(&call->lock);
if (!call->ackr_reason) {
spin_unlock_bh(&call->lock);
ret = 0;
goto out;
}
n = rxrpc_fill_out_ack(call, pkt);
call->ackr_reason = 0;