linux-kernel - [PATCH net 4/6] rxrpc: Don't treat call aborts as conn aborts

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Date:   Tue, 27 Mar 2018 23:44:35 +0100
From:   David Howells <dhowells@...hat.com>
To:     netdev@...r.kernel.org
Cc:     dhowells@...hat.com, linux-afs@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH net 4/6] rxrpc: Don't treat call aborts as conn aborts

If a call-level abort is received for the previous call to complete on a
connection channel, then that abort is queued for the connection processor
to handle.  Unfortunately, the connection processor then assumes without
checking that the abort is connection-level (ie. callNumber is 0) and
distributes it over all active calls on that connection, thereby
incorrectly aborting them.

Fix this by discarding aborts aimed at a completed call.

Further, discard all packets aimed at a call that's complete if there's
currently an active call on a channel, since the DATA packets associated
with the new call automatically terminate the old call.

Fixes: 18bfeba50dfd ("rxrpc: Perform terminal call ACK/ABORT retransmission from conn processor")
Reported-by: Marc Dionne <marc.dionne@...istor.com>
Signed-off-by: David Howells <dhowells@...hat.com>
---

 net/rxrpc/input.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 31bf954480b6..846ec0938953 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -1242,16 +1242,19 @@ void rxrpc_data_ready(struct sock *udp_sk)
 			goto discard_unlock;
 
 		if (sp->hdr.callNumber == chan->last_call) {
-			/* For the previous service call, if completed successfully, we
-			 * discard all further packets.
+			if (chan->call ||
+			    sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
+				goto discard_unlock;
+
+			/* For the previous service call, if completed
+			 * successfully, we discard all further packets.
 			 */
 			if (rxrpc_conn_is_service(conn) &&
-			    (chan->last_type == RXRPC_PACKET_TYPE_ACK ||
-			     sp->hdr.type == RXRPC_PACKET_TYPE_ABORT))
+			    chan->last_type == RXRPC_PACKET_TYPE_ACK)
 				goto discard_unlock;
 
-			/* But otherwise we need to retransmit the final packet from
-			 * data cached in the connection record.
+			/* But otherwise we need to retransmit the final packet
+			 * from data cached in the connection record.
 			 */
 			rxrpc_post_packet_to_conn(conn, skb);
 			goto out_unlock;