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

From: David Howells
Date: Tue Mar 27 2018 - 18:44:46 EST


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@xxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

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;