From 27d0fc431c6b4847231c1490fa541bc3f5a7a351 Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 17 Sep 2016 10:49:13 +0100 Subject: [PATCH] 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 --- net/rxrpc/output.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index 06a9aca739d1..aa0507214b31 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -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; -- 2.30.2