kernel/linux.git/net/rxrpc/io_thread.c, branch v6.18.33

rxrpc: Fix potential UAF after skb_unshare() failure

2026-05-07T04:11:43+00:00

commit 1f2740150f904bfa60e4bad74d65add3ccb5e7f8 upstream. If skb_unshare() fails to unshare a packet due to allocation failure in rxrpc_input_packet(), the skb pointer in the parent (rxrpc_io_thread()) will be NULL'd out. This will likely cause the call to trace_rxrpc_rx_done() to oops. Fix this by moving the unsharing down to where rxrpc_input_call_event() calls rxrpc_input_call_packet(). There are a number of places prior to that where we ignore DATA packets for a variety of reasons (such as the call already being complete) for which an unshare is then avoided. And with that, rxrpc_input_packet() doesn't need to take a pointer to the pointer to the packet, so change that to just a pointer. Fixes: 2d1faf7a0ca3 ("rxrpc: Simplify skbuff accounting in receive path") Closes: https://sashiko.dev/#/patchset/20260408121252.2249051-1-dhowells%40redhat.com Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260422161438.2593376-4-dhowells@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

rxrpc: Only put the call ref if one was acquired

2026-04-18T08:45:01+00:00

commit 6331f1b24a3e85465f6454e003a3e6c22005a5c5 upstream. rxrpc_input_packet_on_conn() can process a to-client packet after the current client call on the channel has already been torn down. In that case chan->call is NULL, rxrpc_try_get_call() returns NULL and there is no reference to drop. The client-side implicit-end error path does not account for that and unconditionally calls rxrpc_put_call(). This turns a protocol error path into a kernel crash instead of rejecting the packet. Only drop the call reference if one was actually acquired. Keep the existing protocol error handling unchanged. Fixes: 5e6ef4f1017c ("rxrpc: Make the I/O thread take over the call and local processor work") Reported-by: Yifan Wu Reported-by: Juefei Pu Signed-off-by: Douya Le Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Signed-off-by: Ao Zhou Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260408121252.2249051-11-dhowells@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix to use conn aborts for conn-wide failures

2025-07-17T14:50:48+00:00

Fix rxrpc to use connection-level aborts for things that affect the whole connection, such as the service ID not matching a local service. Fixes: 57af281e5389 ("rxrpc: Tidy up abort generation infrastructure") Reported-by: Jeffrey Altman Signed-off-by: David Howells Reviewed-by: Jeffrey Altman cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250717074350.3767366-6-dhowells@redhat.com Signed-off-by: Jakub Kicinski

rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE

2025-04-15T00:36:41+00:00

Allow the app to request that CHALLENGEs be passed to it through an out-of-band queue that allows recvmsg() to pick it up so that the app can add data to it with sendmsg(). This will allow the application (AFS or userspace) to interact with the process if it wants to and put values into user-defined fields. This will be used by AFS when talking to a fileserver to supply that fileserver with a crypto key by which callback RPCs can be encrypted (ie. notifications from the fileserver to the client). Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250411095303.2316168-5-dhowells@redhat.com Signed-off-by: Jakub Kicinski

rxrpc: Disable IRQ, not BH, to take the lock for ->attend_link

2024-12-17T02:06:23+00:00

Use spin_lock_irq(), not spin_lock_bh() to take the lock when accessing the ->attend_link() to stop a delay in the I/O thread due to an interrupt being taken in the app thread whilst that holds the lock and vice versa. Fixes: a2ea9a907260 ("rxrpc: Use irq-disabling spinlocks between app and I/O thread") Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/2870146.1734037095@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski

rxrpc: Implement RACK/TLP to deal with transmission stalls [RFC8985]

2024-12-09T21:48:33+00:00

When an rxrpc call is in its transmission phase and is sending a lot of packets, stalls occasionally occur that cause severe performance degradation (eg. increasing the transmission time for a 256MiB payload from 0.7s to 2.5s over a 10G link). rxrpc already implements TCP-style congestion control [RFC5681] and this helps mitigate the effects, but occasionally we're missing a time event that deals with a missing ACK, leading to a stall until the RTO expires. Fix this by implementing RACK/TLP in rxrpc. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Jakub Kicinski

rxrpc: Use irq-disabling spinlocks between app and I/O thread

2024-12-09T21:48:31+00:00

Where a spinlock is used by both the application thread and the I/O thread, use irq-disabling locking so that an interrupt taken on the app thread doesn't also slow down the I/O thread. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Jakub Kicinski

rxrpc: Fix CPU time starvation in I/O thread

2024-12-09T21:48:26+00:00

Starvation can happen in the rxrpc I/O thread because it goes back to the top of the I/O loop after it does any one thing without trying to give any other connection or call CPU time. Also, because it processes one call packet at a time, it tries to do the retransmission loop after each ACK without checking to see if there are other ACKs already in the queue that can update the SACK state. Fix this by: (1) Add a received-packet queue on each call. (2) Distribute packets from the master Rx queue to the individual call, conn and error queues and 'poking' calls to add them to the attend queue first thing in the I/O thread. (3) Go through all the attention-seeking connections and calls before going back to the top of the I/O thread. Each queue is extracted as a whole and then gone through so that new additions to insert themselves into the queue. (4) Make the call event handler go through all the packets currently on the call's rx_queue before transmitting and retransmitting DATA packets. (5) Drop the skb argument from the call event handler as this is now replaced with the rx_queue. Instead, keep track of whether we received a packet or an ACK for the tests that used to rely on that. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20241204074710.990092-14-dhowells@redhat.com Signed-off-by: Jakub Kicinski

rxrpc: Implement path-MTU probing using padded PING ACKs (RFC8899)

2024-12-09T21:48:25+00:00

Implement path-MTU probing (along the lines of RFC8899) by padding some of the PING ACKs we send. PING ACKs get their own individual responses quite apart from the acking of data (though, as ACKs, they fulfil that role also). The probing concentrates on packet sizes that correspond how many subpackets can be stuffed inside a jumbo packet as jumbo DATA packets are just aggregations of individual DATA packets and can be split easily for retransmission purposes. If we want to perform probing, we advertise this by setting the maximum number of jumbo subpackets to 0 in the ack trailer when we send an ACK and see if the peer is also advertising the service. This is interpreted by non-supporting Rx stacks as an indication that jumbo packets aren't supported. The MTU sizes advertised in the ACK trailer AF_RXRPC transmits are pegged at a maximum of 1444 unless pmtud is supported by both sides. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20241204074710.990092-10-dhowells@redhat.com Signed-off-by: Jakub Kicinski

rxrpc: Use umin() and umax() rather than min_t()/max_t() where possible

2024-12-09T21:48:23+00:00

Use umin() and umax() rather than min_t()/max_t() where the type specified is an unsigned type. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20241204074710.990092-4-dhowells@redhat.com Signed-off-by: Jakub Kicinski