Fix the loss of transmission of a call's final ack when a socket gets shut
down.  This means that the server will retransmit the last data packet or
send a ping ack and then get an ICMP indicating the port got closed.  The
server will then view this as a failure.

Fixes: 3136ef49a14c ("rxrpc: Delay terminal ACK transmission on a client call")
Signed-off-by: David Howells <dhowells@redhat.com>

Fix rxrpc_unbundle_conn() to not drop the bundle usage count when cleaning
up an exclusive connection.

Based on the suggested fix from Hillf Danton.

Fixes: 245500d853e9 ("rxrpc: Rewrite the client connection manager")
Reported-by: syzbot+d57aaf84dd8a550e6d91@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Hillf Danton <hdanton@sina.com>

Small conflict around locking in rxrpc_process_event() -
channel_lock moved to bundle in next, while state lock
needs _bh() from net.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

If someone calls setsockopt() twice to set a server key keyring, the first
keyring is leaked.

Fix it to return an error instead if the server key keyring is already set.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>

The keyring containing the server's tokens isn't network-namespaced, so it
shouldn't be looked up with a network namespace.  It is expected to be
owned specifically by the server, so namespacing is unnecessary.

Fixes: a58946c158a0 ("keys: Pass the network namespace into request_key mechanism")
Signed-off-by: David Howells <dhowells@redhat.com>

When a new incoming call arrives at an userspace rxrpc socket on a new
connection that has a security class set, the code currently pushes it onto
the accept queue to hold a ref on it for the socket.  This doesn't work,
however, as recvmsg() pops it off, notices that it's in the SERVER_SECURING
state and discards the ref.  This means that the call runs out of refs too
early and the kernel oopses.

By contrast, a kernel rxrpc socket manually pre-charges the incoming call
pool with calls that already have user call IDs assigned, so they are ref'd
by the call tree on the socket.

Change the mode of operation for userspace rxrpc server sockets to work
like this too.  Although this is a UAPI change, server sockets aren't
currently functional.

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>

conn->state_lock may be taken in softirq mode, but a previous patch
replaced an outer lock in the response-packet event handling code, and lost
the _bh from that when doing so.

Fix this by applying the _bh annotation to the state_lock locking.

Fixes: a1399f8bb033 ("rxrpc: Call channels should have separate call number spaces")
Signed-off-by: David Howells <dhowells@redhat.com>

If rxrpc_read() (which allows KEYCTL_READ to read a key), sees a token of a
type it doesn't recognise, it can BUG in a couple of places, which is
unnecessary as it can easily get back to userspace.

Fix this to print an error message instead.

Fixes: 99455153d067 ("RxRPC: Parse security index 5 keys (Kerberos 5)")
Signed-off-by: David Howells <dhowells@redhat.com>

The session key should be encoded with just the 8 data bytes and
no length; ENCODE_DATA precedes it with a 4 byte length, which
confuses some existing tools that try to parse this format.

Add an ENCODE_BYTES macro that does not include a length, and use
it for the key.  Also adjust the expected length.

Note that commit 774521f353e1d ("rxrpc: Fix an assertion in
rxrpc_read()") had fixed a BUG by changing the length rather than
fixing the encoding.  The original length was correct.

Fixes: 99455153d067 ("RxRPC: Parse security index 5 keys (Kerberos 5)")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

When setting up a client connection, a second ref is accidentally obtained
on the connection bundle (we get one when allocating the conn and a second
one when adding the conn to the bundle).

Fix it to only use the ref obtained by rxrpc_alloc_client_connection() and
not to add a second when adding the candidate conn to the bundle.

Fixes: 245500d853e9 ("rxrpc: Rewrite the client connection manager")
Signed-off-by: David Howells <dhowells@redhat.com>