diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 84464b29e54a..03a984e661bc 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -18,6 +18,7 @@
  */
 #define rxrpc_skb_traces \
 	EM(rxrpc_skb_cleaned,			"CLN") \
+	EM(rxrpc_skb_cloned_jumbo,		"CLJ") \
 	EM(rxrpc_skb_freed,			"FRE") \
 	EM(rxrpc_skb_got,			"GOT") \
 	EM(rxrpc_skb_lost,			"*L*") \
@@ -630,16 +631,15 @@ TRACE_EVENT(rxrpc_transmit,
 
 TRACE_EVENT(rxrpc_rx_data,
 	    TP_PROTO(unsigned int call, rxrpc_seq_t seq,
-		     rxrpc_serial_t serial, u8 flags, u8 anno),
+		     rxrpc_serial_t serial, u8 flags),
 
-	    TP_ARGS(call, seq, serial, flags, anno),
+	    TP_ARGS(call, seq, serial, flags),
 
 	    TP_STRUCT__entry(
 		    __field(unsigned int,		call		)
 		    __field(rxrpc_seq_t,		seq		)
 		    __field(rxrpc_serial_t,		serial		)
 		    __field(u8,				flags		)
-		    __field(u8,				anno		)
 			     ),
 
 	    TP_fast_assign(
@@ -647,15 +647,13 @@ TRACE_EVENT(rxrpc_rx_data,
 		    __entry->seq = seq;
 		    __entry->serial = serial;
 		    __entry->flags = flags;
-		    __entry->anno = anno;
 			   ),
 
-	    TP_printk("c=%08x DATA %08x q=%08x fl=%02x a=%02x",
+	    TP_printk("c=%08x DATA %08x q=%08x fl=%02x",
 		      __entry->call,
 		      __entry->serial,
 		      __entry->seq,
-		      __entry->flags,
-		      __entry->anno)
+		      __entry->flags)
 	    );
 
 TRACE_EVENT(rxrpc_rx_ack,
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 5a81545a58d5..e93ed18816b1 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -195,19 +195,14 @@ struct rxrpc_host_header {
  * - max 48 bytes (struct sk_buff::cb)
  */
 struct rxrpc_skb_priv {
-	atomic_t	nr_ring_pins;		/* Number of rxtx ring pins */
-	u8		nr_subpackets;		/* Number of subpackets */
-	u8		rx_flags;		/* Received packet flags */
-#define RXRPC_SKB_INCL_LAST	0x01		/* - Includes last packet */
-	union {
-		int		remain;		/* amount of space remaining for next write */
-
-		/* List of requested ACKs on subpackets */
-		unsigned long	rx_req_ack[(RXRPC_MAX_NR_JUMBO + BITS_PER_LONG - 1) /
-					   BITS_PER_LONG];
-	};
-
-	struct rxrpc_host_header hdr;		/* RxRPC packet header from this packet */
+	u16		remain;
+	u16		offset;		/* Offset of data */
+	u16		len;		/* Length of data */
+	u8		rx_flags;	/* Received packet flags */
+	u8		flags;
+#define RXRPC_RX_VERIFIED	0x01
+
+	struct rxrpc_host_header hdr;	/* RxRPC packet header from this packet */
 };
 
 #define rxrpc_skb(__skb) ((struct rxrpc_skb_priv *) &(__skb)->cb)
@@ -252,16 +247,11 @@ struct rxrpc_security {
 	int (*secure_packet)(struct rxrpc_call *, struct sk_buff *, size_t);
 
 	/* verify the security on a received packet */
-	int (*verify_packet)(struct rxrpc_call *, struct sk_buff *,
-			     unsigned int, unsigned int, rxrpc_seq_t, u16);
+	int (*verify_packet)(struct rxrpc_call *, struct sk_buff *);
 
 	/* Free crypto request on a call */
 	void (*free_call_crypto)(struct rxrpc_call *);
 
-	/* Locate the data in a received packet that has been verified. */
-	void (*locate_data)(struct rxrpc_call *, struct sk_buff *,
-			    unsigned int *, unsigned int *);
-
 	/* issue a challenge */
 	int (*issue_challenge)(struct rxrpc_connection *);
 
@@ -628,7 +618,6 @@ struct rxrpc_call {
 	int			debug_id;	/* debug ID for printks */
 	unsigned short		rx_pkt_offset;	/* Current recvmsg packet offset */
 	unsigned short		rx_pkt_len;	/* Current recvmsg packet len */
-	bool			rx_pkt_last;	/* Current recvmsg packet is last */
 
 	/* Rx/Tx circular buffer, depending on phase.
 	 *
@@ -652,8 +641,6 @@ struct rxrpc_call {
 #define RXRPC_TX_ANNO_LAST	0x04
 #define RXRPC_TX_ANNO_RESENT	0x08
 
-#define RXRPC_RX_ANNO_SUBPACKET	0x3f		/* Subpacket number in jumbogram */
-#define RXRPC_RX_ANNO_VERIFIED	0x80		/* Set if verified and decrypted */
 	rxrpc_seq_t		tx_hard_ack;	/* Dead slot in buffer; the first transmitted but
 						 * not hard-ACK'd packet follows this.
 						 */
@@ -681,7 +668,6 @@ struct rxrpc_call {
 	rxrpc_serial_t		rx_serial;	/* Highest serial received for this call */
 	u8			rx_winsize;	/* Size of Rx window */
 	u8			tx_winsize;	/* Maximum size of Tx window */
-	u8			nr_jumbo_bad;	/* Number of jumbo dups/exceeds-windows */
 
 	spinlock_t		input_lock;	/* Lock for packet input to this call */
 
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 4df1bdc4de6c..0e7545ed0128 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -313,78 +313,178 @@ static bool rxrpc_receiving_reply(struct rxrpc_call *call)
 }
 
 /*
- * Scan a data packet to validate its structure and to work out how many
- * subpackets it contains.
- *
- * A jumbo packet is a collection of consecutive packets glued together with
- * little headers between that indicate how to change the initial header for
- * each subpacket.
- *
- * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
- * the last are RXRPC_JUMBO_DATALEN in size.  The last subpacket may be of any
- * size.
+ * Process a DATA packet, adding the packet to the Rx ring.  The caller's
+ * packet ref must be passed on or discarded.
  */
-static bool rxrpc_validate_data(struct sk_buff *skb)
+static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	unsigned int offset = sizeof(struct rxrpc_wire_header);
-	unsigned int len = skb->len;
-	u8 flags = sp->hdr.flags;
+	rxrpc_serial_t serial = sp->hdr.serial;
+	rxrpc_seq_t seq = sp->hdr.seq, hard_ack;
+	unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK;
+	bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
+	bool acked = false;
 
-	for (;;) {
-		if (flags & RXRPC_REQUEST_ACK)
-			__set_bit(sp->nr_subpackets, sp->rx_req_ack);
-		sp->nr_subpackets++;
+	rxrpc_inc_stat(call->rxnet, stat_rx_data);
+	if (sp->hdr.flags & RXRPC_REQUEST_ACK)
+		rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack);
+	if (sp->hdr.flags & RXRPC_JUMBO_PACKET)
+		rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo);
 
-		if (!(flags & RXRPC_JUMBO_PACKET))
-			break;
+	hard_ack = READ_ONCE(call->rx_hard_ack);
 
-		if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
-			goto protocol_error;
-		if (flags & RXRPC_LAST_PACKET)
-			goto protocol_error;
-		offset += RXRPC_JUMBO_DATALEN;
-		if (skb_copy_bits(skb, offset, &flags, 1) < 0)
-			goto protocol_error;
-		offset += sizeof(struct rxrpc_jumbo_header);
+	_proto("Rx DATA %%%u { #%x l=%u }", serial, seq, last);
+
+	if (last) {
+		if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+		    seq != call->rx_top) {
+			rxrpc_proto_abort("LSN", call, seq);
+			goto out;
+		}
+	} else {
+		if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+		    after_eq(seq, call->rx_top)) {
+			rxrpc_proto_abort("LSA", call, seq);
+			goto out;
+		}
 	}
 
-	if (flags & RXRPC_LAST_PACKET)
-		sp->rx_flags |= RXRPC_SKB_INCL_LAST;
-	return true;
+	trace_rxrpc_rx_data(call->debug_id, seq, serial, sp->hdr.flags);
 
-protocol_error:
-	return false;
+	if (before_eq(seq, hard_ack)) {
+		rxrpc_send_ACK(call, RXRPC_ACK_DUPLICATE, serial,
+			       rxrpc_propose_ack_input_data);
+		goto out;
+	}
+
+	if (call->rxtx_buffer[ix]) {
+		rxrpc_send_ACK(call, RXRPC_ACK_DUPLICATE, serial,
+			       rxrpc_propose_ack_input_data);
+		goto out;
+	}
+
+	if (after(seq, hard_ack + call->rx_winsize)) {
+		rxrpc_send_ACK(call, RXRPC_ACK_EXCEEDS_WINDOW, serial,
+			       rxrpc_propose_ack_input_data);
+		goto out;
+	}
+
+	if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
+		rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, serial,
+			       rxrpc_propose_ack_input_data);
+		acked = true;
+	}
+
+	if (after(seq, call->ackr_highest_seq))
+		call->ackr_highest_seq = seq;
+
+	/* Queue the packet.  We use a couple of memory barriers here as need
+	 * to make sure that rx_top is perceived to be set after the buffer
+	 * pointer and that the buffer pointer is set after the annotation and
+	 * the skb data.
+	 *
+	 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
+	 * and also rxrpc_fill_out_ack().
+	 */
+	call->rxtx_annotations[ix] = 1;
+	smp_wmb();
+	call->rxtx_buffer[ix] = skb;
+	if (after(seq, call->rx_top)) {
+		smp_store_release(&call->rx_top, seq);
+	} else if (before(seq, call->rx_top)) {
+		/* Send an immediate ACK if we fill in a hole */
+		if (!acked) {
+			rxrpc_send_ACK(call, RXRPC_ACK_DELAY, serial,
+				       rxrpc_propose_ack_input_data_hole);
+			acked = true;
+		}
+	}
+
+	/* From this point on, we're not allowed to touch the packet any longer
+	 * as its ref now belongs to the Rx ring.
+	 */
+	skb = NULL;
+	sp = NULL;
+
+	if (last) {
+		set_bit(RXRPC_CALL_RX_LAST, &call->flags);
+		trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
+	} else {
+		trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
+	}
+
+	if (after_eq(seq, call->rx_expect_next)) {
+		if (after(seq, call->rx_expect_next)) {
+			_net("OOS %u > %u", seq, call->rx_expect_next);
+			rxrpc_send_ACK(call, RXRPC_ACK_OUT_OF_SEQUENCE, serial,
+				       rxrpc_propose_ack_input_data);
+			acked = true;
+		}
+		call->rx_expect_next = seq + 1;
+	}
+
+out:
+	if (!acked &&
+	    atomic_inc_return(&call->ackr_nr_unacked) > 2)
+		rxrpc_send_ACK(call, RXRPC_ACK_IDLE, serial,
+			       rxrpc_propose_ack_input_data);
+	else
+		rxrpc_propose_delay_ACK(call, serial,
+					rxrpc_propose_ack_input_data);
+
+	trace_rxrpc_notify_socket(call->debug_id, serial);
+	rxrpc_notify_socket(call);
+
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	_leave(" [queued]");
 }
 
 /*
- * Handle reception of a duplicate packet.
- *
- * We have to take care to avoid an attack here whereby we're given a series of
- * jumbograms, each with a sequence number one before the preceding one and
- * filled up to maximum UDP size.  If they never send us the first packet in
- * the sequence, they can cause us to have to hold on to around 2MiB of kernel
- * space until the call times out.
- *
- * We limit the space usage by only accepting three duplicate jumbo packets per
- * call.  After that, we tell the other side we're no longer accepting jumbos
- * (that information is encoded in the ACK packet).
+ * Split a jumbo packet and file the bits separately.
  */
-static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
-				 bool is_jumbo, bool *_jumbo_bad)
+static bool rxrpc_input_split_jumbo(struct rxrpc_call *call, struct sk_buff *skb)
 {
-	/* Discard normal packets that are duplicates. */
-	if (is_jumbo)
-		return;
+	struct rxrpc_jumbo_header jhdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb), *jsp;
+	struct sk_buff *jskb;
+	unsigned int offset = sizeof(struct rxrpc_wire_header);
+	unsigned int len = skb->len - offset;
 
-	/* Skip jumbo subpackets that are duplicates.  When we've had three or
-	 * more partially duplicate jumbo packets, we refuse to take any more
-	 * jumbos for this call.
-	 */
-	if (!*_jumbo_bad) {
-		call->nr_jumbo_bad++;
-		*_jumbo_bad = true;
+	while (sp->hdr.flags & RXRPC_JUMBO_PACKET) {
+		if (len < RXRPC_JUMBO_SUBPKTLEN)
+			goto protocol_error;
+		if (sp->hdr.flags & RXRPC_LAST_PACKET)
+			goto protocol_error;
+		if (skb_copy_bits(skb, offset + RXRPC_JUMBO_DATALEN,
+				  &jhdr, sizeof(jhdr)) < 0)
+			goto protocol_error;
+
+		jskb = skb_clone(skb, GFP_ATOMIC);
+		if (!jskb) {
+			kdebug("couldn't clone");
+			return false;
+		}
+		rxrpc_new_skb(jskb, rxrpc_skb_cloned_jumbo);
+		jsp = rxrpc_skb(jskb);
+		jsp->offset = offset;
+		jsp->len = RXRPC_JUMBO_DATALEN;
+		rxrpc_input_data_one(call, jskb);
+
+		sp->hdr.flags = jhdr.flags;
+		sp->hdr._rsvd = ntohs(jhdr._rsvd);
+		sp->hdr.seq++;
+		sp->hdr.serial++;
+		offset += RXRPC_JUMBO_SUBPKTLEN;
+		len -= RXRPC_JUMBO_SUBPKTLEN;
 	}
+
+	sp->offset = offset;
+	sp->len    = len;
+	rxrpc_input_data_one(call, skb);
+	return true;
+
+protocol_error:
+	return false;
 }
 
 /*
@@ -395,16 +495,14 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	enum rxrpc_call_state state;
-	unsigned int j, nr_subpackets, nr_unacked = 0;
-	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = serial;
-	rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack;
-	bool jumbo_bad = false;
+	rxrpc_serial_t serial = sp->hdr.serial;
+	rxrpc_seq_t seq0 = sp->hdr.seq;
 
 	_enter("{%u,%u},{%u,%u}",
 	       call->rx_hard_ack, call->rx_top, skb->len, seq0);
 
-	_proto("Rx DATA %%%u { #%u f=%02x n=%u }",
-	       sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets);
+	_proto("Rx DATA %%%u { #%u f=%02x }",
+	       sp->hdr.serial, seq0, sp->hdr.flags);
 
 	state = READ_ONCE(call->state);
 	if (state >= RXRPC_CALL_COMPLETE) {
@@ -412,6 +510,24 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 		return;
 	}
 
+	/* Unshare the packet so that it can be modified for in-place
+	 * decryption.
+	 */
+	if (sp->hdr.securityIndex != 0) {
+		struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
+		if (!nskb) {
+			rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
+			return;
+		}
+
+		if (nskb != skb) {
+			rxrpc_eaten_skb(skb, rxrpc_skb_received);
+			skb = nskb;
+			rxrpc_new_skb(skb, rxrpc_skb_unshared);
+			sp = rxrpc_skb(skb);
+		}
+	}
+
 	if (state == RXRPC_CALL_SERVER_RECV_REQUEST) {
 		unsigned long timo = READ_ONCE(call->next_req_timo);
 		unsigned long now, expect_req_by;
@@ -425,12 +541,6 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 		}
 	}
 
-	rxrpc_inc_stat(call->rxnet, stat_rx_data);
-	if (sp->hdr.flags & RXRPC_REQUEST_ACK)
-		rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack);
-	if (sp->hdr.flags & RXRPC_JUMBO_PACKET)
-		rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo);
-
 	spin_lock(&call->input_lock);
 
 	/* Received data implicitly ACKs all of the request packets we sent
@@ -439,154 +549,15 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 	if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
 	     state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
 	    !rxrpc_receiving_reply(call))
-		goto unlock;
-
-	hard_ack = READ_ONCE(call->rx_hard_ack);
-
-	nr_subpackets = sp->nr_subpackets;
-	if (nr_subpackets > 1) {
-		if (call->nr_jumbo_bad > 3) {
-			rxrpc_send_ACK(call, RXRPC_ACK_NOSPACE, serial,
-				       rxrpc_propose_ack_input_data);
-			goto unlock;
-		}
-	}
-
-	for (j = 0; j < nr_subpackets; j++) {
-		rxrpc_serial_t serial = sp->hdr.serial + j;
-		rxrpc_seq_t seq = seq0 + j;
-		unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK;
-		bool terminal = (j == nr_subpackets - 1);
-		bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST);
-		bool acked = false;
-		u8 flags, annotation = j;
-
-		_proto("Rx DATA+%u %%%u { #%x t=%u l=%u }",
-		     j, serial, seq, terminal, last);
-
-		if (last) {
-			if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
-			    seq != call->rx_top) {
-				rxrpc_proto_abort("LSN", call, seq);
-				goto unlock;
-			}
-		} else {
-			if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
-			    after_eq(seq, call->rx_top)) {
-				rxrpc_proto_abort("LSA", call, seq);
-				goto unlock;
-			}
-		}
-
-		flags = 0;
-		if (last)
-			flags |= RXRPC_LAST_PACKET;
-		if (!terminal)
-			flags |= RXRPC_JUMBO_PACKET;
-		if (test_bit(j, sp->rx_req_ack))
-			flags |= RXRPC_REQUEST_ACK;
-		trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation);
-
-		if (before_eq(seq, hard_ack)) {
-			rxrpc_send_ACK(call, RXRPC_ACK_DUPLICATE, serial,
-				       rxrpc_propose_ack_input_data);
-			continue;
-		}
-
-		if (call->rxtx_buffer[ix]) {
-			rxrpc_input_dup_data(call, seq, nr_subpackets > 1,
-					     &jumbo_bad);
-			rxrpc_send_ACK(call, RXRPC_ACK_DUPLICATE, serial,
-				       rxrpc_propose_ack_input_data);
-			continue;
-		}
-
-		if (after(seq, hard_ack + call->rx_winsize)) {
-			rxrpc_send_ACK(call, RXRPC_ACK_EXCEEDS_WINDOW, serial,
-				       rxrpc_propose_ack_input_data);
-			if (flags & RXRPC_JUMBO_PACKET) {
-				if (!jumbo_bad) {
-					call->nr_jumbo_bad++;
-					jumbo_bad = true;
-				}
-			}
-
-			goto unlock;
-		}
-
-		if (flags & RXRPC_REQUEST_ACK) {
-			rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, serial,
-				       rxrpc_propose_ack_input_data);
-			acked = true;
-		}
-
-		if (after(seq0, call->ackr_highest_seq))
-			call->ackr_highest_seq = seq0;
-
-		/* Queue the packet.  We use a couple of memory barriers here as need
-		 * to make sure that rx_top is perceived to be set after the buffer
-		 * pointer and that the buffer pointer is set after the annotation and
-		 * the skb data.
-		 *
-		 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
-		 * and also rxrpc_fill_out_ack().
-		 */
-		if (!terminal)
-			rxrpc_get_skb(skb, rxrpc_skb_got);
-		call->rxtx_annotations[ix] = annotation;
-		smp_wmb();
-		call->rxtx_buffer[ix] = skb;
-		if (after(seq, call->rx_top)) {
-			smp_store_release(&call->rx_top, seq);
-		} else if (before(seq, call->rx_top)) {
-			/* Send an immediate ACK if we fill in a hole */
-			if (!acked) {
-				rxrpc_send_ACK(call, RXRPC_ACK_DELAY, serial,
-					       rxrpc_propose_ack_input_data_hole);
-				acked = true;
-			}
-		}
-
-		if (terminal) {
-			/* From this point on, we're not allowed to touch the
-			 * packet any longer as its ref now belongs to the Rx
-			 * ring.
-			 */
-			skb = NULL;
-			sp = NULL;
-		}
-
-		if (last) {
-			set_bit(RXRPC_CALL_RX_LAST, &call->flags);
-			trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
-		} else {
-			trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
-		}
-
-		if (after_eq(seq, call->rx_expect_next)) {
-			if (after(seq, call->rx_expect_next)) {
-				_net("OOS %u > %u", seq, call->rx_expect_next);
-				rxrpc_send_ACK(call, RXRPC_ACK_OUT_OF_SEQUENCE, serial,
-					       rxrpc_propose_ack_input_data);
-				acked = true;
-			}
-			call->rx_expect_next = seq + 1;
-		}
+		goto out;
 
-		if (!acked) {
-			nr_unacked++;
-			ack_serial = serial;
-		}
+	if (!rxrpc_input_split_jumbo(call, skb)) {
+		rxrpc_proto_abort("VLD", call, sp->hdr.seq);
+		goto out;
 	}
+	skb = NULL;
 
-unlock:
-	if (atomic_add_return(nr_unacked, &call->ackr_nr_unacked) > 2)
-		rxrpc_send_ACK(call, RXRPC_ACK_IDLE, ack_serial,
-			       rxrpc_propose_ack_input_data);
-	else
-		rxrpc_propose_delay_ACK(call, ack_serial,
-					rxrpc_propose_ack_input_data);
-
+out:
 	trace_rxrpc_notify_socket(call->debug_id, serial);
 	rxrpc_notify_socket(call);
 
@@ -1288,8 +1259,6 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 		if (sp->hdr.callNumber == 0 ||
 		    sp->hdr.seq == 0)
 			goto bad_message;
-		if (!rxrpc_validate_data(skb))
-			goto bad_message;
 
 		/* Unshare the packet so that it can be modified for in-place
 		 * decryption.
@@ -1403,7 +1372,7 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 				trace_rxrpc_rx_data(chan->call_debug_id,
 						    sp->hdr.seq,
 						    sp->hdr.serial,
-						    sp->hdr.flags, 0);
+						    sp->hdr.flags);
 			rxrpc_post_packet_to_conn(conn, skb);
 			goto out;
 		}
diff --git a/net/rxrpc/insecure.c b/net/rxrpc/insecure.c
index 9aae99d67833..fd68f0e3af27 100644
--- a/net/rxrpc/insecure.c
+++ b/net/rxrpc/insecure.c
@@ -31,10 +31,11 @@ static int none_secure_packet(struct rxrpc_call *call, struct sk_buff *skb,
 	return 0;
 }
 
-static int none_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
-			      unsigned int offset, unsigned int len,
-			      rxrpc_seq_t seq, u16 expected_cksum)
+static int none_verify_packet(struct rxrpc_call *call, struct sk_buff *skb)
 {
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	sp->flags |= RXRPC_RX_VERIFIED;
 	return 0;
 }
 
@@ -42,11 +43,6 @@ static void none_free_call_crypto(struct rxrpc_call *call)
 {
 }
 
-static void none_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
-			     unsigned int *_offset, unsigned int *_len)
-{
-}
-
 static int none_respond_to_challenge(struct rxrpc_connection *conn,
 				     struct sk_buff *skb,
 				     u32 *_abort_code)
@@ -95,7 +91,6 @@ const struct rxrpc_security rxrpc_no_security = {
 	.how_much_data			= none_how_much_data,
 	.secure_packet			= none_secure_packet,
 	.verify_packet			= none_verify_packet,
-	.locate_data			= none_locate_data,
 	.respond_to_challenge		= none_respond_to_challenge,
 	.verify_response		= none_verify_response,
 	.clear				= none_clear,
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index d35657b659ad..f7bb792c8aa1 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -121,7 +121,7 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
 
 	mtu = conn->params.peer->if_mtu;
 	mtu -= conn->params.peer->hdrsize;
-	jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
+	jmax = rxrpc_rx_jumbo_max;
 	ackinfo.rxMTU		= htonl(rxrpc_rx_mtu);
 	ackinfo.maxMTU		= htonl(mtu);
 	ackinfo.rwind		= htonl(call->rx_winsize);
diff --git a/net/rxrpc/protocol.h b/net/rxrpc/protocol.h
index f3d4e2700901..6760cb99c6d6 100644
--- a/net/rxrpc/protocol.h
+++ b/net/rxrpc/protocol.h
@@ -84,7 +84,7 @@ struct rxrpc_jumbo_header {
 		__be16	_rsvd;		/* reserved */
 		__be16	cksum;		/* kerberos security checksum */
 	};
-};
+} __packed;
 
 #define RXRPC_JUMBO_DATALEN	1412	/* non-terminal jumbo packet data length */
 #define RXRPC_JUMBO_SUBPKTLEN	(RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index 77cde6311559..401aae687830 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -222,7 +222,6 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
 	rxrpc_serial_t serial;
 	rxrpc_seq_t hard_ack, top;
 	bool last = false;
-	u8 subpacket;
 	int ix;
 
 	_enter("%d", call->debug_id);
@@ -237,11 +236,9 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
 	rxrpc_see_skb(skb, rxrpc_skb_rotated);
 	sp = rxrpc_skb(skb);
 
-	subpacket = call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET;
-	serial = sp->hdr.serial + subpacket;
+	serial = sp->hdr.serial;
 
-	if (subpacket == sp->nr_subpackets - 1 &&
-	    sp->rx_flags & RXRPC_SKB_INCL_LAST)
+	if (sp->hdr.flags & RXRPC_LAST_PACKET)
 		last = true;
 
 	call->rxtx_buffer[ix] = NULL;
@@ -266,80 +263,15 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
 }
 
 /*
- * Decrypt and verify a (sub)packet.  The packet's length may be changed due to
- * padding, but if this is the case, the packet length will be resident in the
- * socket buffer.  Note that we can't modify the master skb info as the skb may
- * be the home to multiple subpackets.
+ * Decrypt and verify a DATA packet.
  */
-static int rxrpc_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
-			       u8 annotation,
-			       unsigned int offset, unsigned int len)
+static int rxrpc_verify_data(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	rxrpc_seq_t seq = sp->hdr.seq;
-	u16 cksum = sp->hdr.cksum;
-	u8 subpacket = annotation & RXRPC_RX_ANNO_SUBPACKET;
 
-	_enter("");
-
-	/* For all but the head jumbo subpacket, the security checksum is in a
-	 * jumbo header immediately prior to the data.
-	 */
-	if (subpacket > 0) {
-		__be16 tmp;
-		if (skb_copy_bits(skb, offset - 2, &tmp, 2) < 0)
-			BUG();
-		cksum = ntohs(tmp);
-		seq += subpacket;
-	}
-
-	return call->security->verify_packet(call, skb, offset, len,
-					     seq, cksum);
-}
-
-/*
- * Locate the data within a packet.  This is complicated by:
- *
- * (1) An skb may contain a jumbo packet - so we have to find the appropriate
- *     subpacket.
- *
- * (2) The (sub)packets may be encrypted and, if so, the encrypted portion
- *     contains an extra header which includes the true length of the data,
- *     excluding any encrypted padding.
- */
-static int rxrpc_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
-			     u8 *_annotation,
-			     unsigned int *_offset, unsigned int *_len,
-			     bool *_last)
-{
-	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	unsigned int offset = sizeof(struct rxrpc_wire_header);
-	unsigned int len;
-	bool last = false;
-	int ret;
-	u8 annotation = *_annotation;
-	u8 subpacket = annotation & RXRPC_RX_ANNO_SUBPACKET;
-
-	/* Locate the subpacket */
-	offset += subpacket * RXRPC_JUMBO_SUBPKTLEN;
-	len = skb->len - offset;
-	if (subpacket < sp->nr_subpackets - 1)
-		len = RXRPC_JUMBO_DATALEN;
-	else if (sp->rx_flags & RXRPC_SKB_INCL_LAST)
-		last = true;
-
-	if (!(annotation & RXRPC_RX_ANNO_VERIFIED)) {
-		ret = rxrpc_verify_packet(call, skb, annotation, offset, len);
-		if (ret < 0)
-			return ret;
-		*_annotation |= RXRPC_RX_ANNO_VERIFIED;
-	}
-
-	*_offset = offset;
-	*_len = len;
-	*_last = last;
-	call->security->locate_data(call, skb, _offset, _len);
-	return 0;
+	if (sp->flags & RXRPC_RX_VERIFIED)
+		return 0;
+	return call->security->verify_packet(call, skb);
 }
 
 /*
@@ -356,13 +288,11 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
 	rxrpc_serial_t serial;
 	rxrpc_seq_t hard_ack, top, seq;
 	size_t remain;
-	bool rx_pkt_last;
 	unsigned int rx_pkt_offset, rx_pkt_len;
 	int ix, copy, ret = -EAGAIN, ret2;
 
 	rx_pkt_offset = call->rx_pkt_offset;
 	rx_pkt_len = call->rx_pkt_len;
-	rx_pkt_last = call->rx_pkt_last;
 
 	if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) {
 		seq = call->rx_hard_ack;
@@ -391,7 +321,6 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
 
 		if (!(flags & MSG_PEEK)) {
 			serial = sp->hdr.serial;
-			serial += call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET;
 			trace_rxrpc_receive(call, rxrpc_receive_front,
 					    serial, seq);
 		}
@@ -400,10 +329,9 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
 			sock_recv_timestamp(msg, sock->sk, skb);
 
 		if (rx_pkt_offset == 0) {
-			ret2 = rxrpc_locate_data(call, skb,
-						 &call->rxtx_annotations[ix],
-						 &rx_pkt_offset, &rx_pkt_len,
-						 &rx_pkt_last);
+			ret2 = rxrpc_verify_data(call, skb);
+			rx_pkt_offset = sp->offset;
+			rx_pkt_len = sp->len;
 			trace_rxrpc_recvdata(call, rxrpc_recvmsg_next, seq,
 					     rx_pkt_offset, rx_pkt_len, ret2);
 			if (ret2 < 0) {
@@ -443,16 +371,13 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
 		}
 
 		/* The whole packet has been transferred. */
-		if (!(flags & MSG_PEEK))
-			rxrpc_rotate_rx_window(call);
+		if (sp->hdr.flags & RXRPC_LAST_PACKET)
+			ret = 1;
 		rx_pkt_offset = 0;
 		rx_pkt_len = 0;
 
-		if (rx_pkt_last) {
-			ASSERTCMP(seq, ==, READ_ONCE(call->rx_top));
-			ret = 1;
-			goto out;
-		}
+		if (!(flags & MSG_PEEK))
+			rxrpc_rotate_rx_window(call);
 
 		seq++;
 	}
@@ -461,7 +386,6 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
 	if (!(flags & MSG_PEEK)) {
 		call->rx_pkt_offset = rx_pkt_offset;
 		call->rx_pkt_len = rx_pkt_len;
-		call->rx_pkt_last = rx_pkt_last;
 	}
 done:
 	trace_rxrpc_recvdata(call, rxrpc_recvmsg_data_return, seq,
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 78fa0524156f..b19937776aa9 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -439,11 +439,11 @@ static int rxkad_secure_packet(struct rxrpc_call *call,
  * decrypt partial encryption on a packet (level 1 security)
  */
 static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
-				 unsigned int offset, unsigned int len,
 				 rxrpc_seq_t seq,
 				 struct skcipher_request *req)
 {
 	struct rxkad_level1_hdr sechdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	struct rxrpc_crypt iv;
 	struct scatterlist sg[16];
 	bool aborted;
@@ -453,9 +453,9 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
 
 	_enter("");
 
-	if (len < 8) {
+	if (sp->len < 8) {
 		aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H",
-					   RXKADSEALEDINCON);
+					     RXKADSEALEDINCON);
 		goto protocol_error;
 	}
 
@@ -463,7 +463,7 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
 	 * directly into the target buffer.
 	 */
 	sg_init_table(sg, ARRAY_SIZE(sg));
-	ret = skb_to_sgvec(skb, sg, offset, 8);
+	ret = skb_to_sgvec(skb, sg, sp->offset, 8);
 	if (unlikely(ret < 0))
 		return ret;
 
@@ -477,12 +477,13 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
 	skcipher_request_zero(req);
 
 	/* Extract the decrypted packet length */
-	if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
+	if (skb_copy_bits(skb, sp->offset, &sechdr, sizeof(sechdr)) < 0) {
 		aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1",
 					     RXKADDATALEN);
 		goto protocol_error;
 	}
-	len -= sizeof(sechdr);
+	sp->offset += sizeof(sechdr);
+	sp->len    -= sizeof(sechdr);
 
 	buf = ntohl(sechdr.data_size);
 	data_size = buf & 0xffff;
@@ -496,11 +497,12 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
 		goto protocol_error;
 	}
 
-	if (data_size > len) {
+	if (data_size > sp->len) {
 		aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L",
 					     RXKADDATALEN);
 		goto protocol_error;
 	}
+	sp->len = data_size;
 
 	_leave(" = 0 [dlen=%x]", data_size);
 	return 0;
@@ -515,12 +517,12 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
  * wholly decrypt a packet (level 2 security)
  */
 static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
-				 unsigned int offset, unsigned int len,
 				 rxrpc_seq_t seq,
 				 struct skcipher_request *req)
 {
 	const struct rxrpc_key_token *token;
 	struct rxkad_level2_hdr sechdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	struct rxrpc_crypt iv;
 	struct scatterlist _sg[4], *sg;
 	bool aborted;
@@ -528,9 +530,9 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
 	u16 check;
 	int nsg, ret;
 
-	_enter(",{%d}", skb->len);
+	_enter(",{%d}", sp->len);
 
-	if (len < 8) {
+	if (sp->len < 8) {
 		aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H",
 					     RXKADSEALEDINCON);
 		goto protocol_error;
@@ -550,7 +552,7 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
 	}
 
 	sg_init_table(sg, nsg);
-	ret = skb_to_sgvec(skb, sg, offset, len);
+	ret = skb_to_sgvec(skb, sg, sp->offset, sp->len);
 	if (unlikely(ret < 0)) {
 		if (sg != _sg)
 			kfree(sg);
@@ -563,19 +565,20 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
 
 	skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
 	skcipher_request_set_callback(req, 0, NULL, NULL);
-	skcipher_request_set_crypt(req, sg, sg, len, iv.x);
+	skcipher_request_set_crypt(req, sg, sg, sp->len, iv.x);
 	crypto_skcipher_decrypt(req);
 	skcipher_request_zero(req);
 	if (sg != _sg)
 		kfree(sg);
 
 	/* Extract the decrypted packet length */
-	if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
+	if (skb_copy_bits(skb, sp->offset, &sechdr, sizeof(sechdr)) < 0) {
 		aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2",
 					     RXKADDATALEN);
 		goto protocol_error;
 	}
-	len -= sizeof(sechdr);
+	sp->offset += sizeof(sechdr);
+	sp->len    -= sizeof(sechdr);
 
 	buf = ntohl(sechdr.data_size);
 	data_size = buf & 0xffff;
@@ -589,12 +592,13 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
 		goto protocol_error;
 	}
 
-	if (data_size > len) {
+	if (data_size > sp->len) {
 		aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L",
 					     RXKADDATALEN);
 		goto protocol_error;
 	}
 
+	sp->len = data_size;
 	_leave(" = 0 [dlen=%x]", data_size);
 	return 0;
 
@@ -609,16 +613,15 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
 }
 
 /*
- * Verify the security on a received packet or subpacket (if part of a
- * jumbo packet).
+ * Verify the security on a received packet and the subpackets therein.
  */
-static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
-			       unsigned int offset, unsigned int len,
-			       rxrpc_seq_t seq, u16 expected_cksum)
+static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb)
 {
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	struct skcipher_request	*req;
 	struct rxrpc_crypt iv;
 	struct scatterlist sg;
+	rxrpc_seq_t seq = sp->hdr.seq;
 	bool aborted;
 	u16 cksum;
 	u32 x, y;
@@ -654,7 +657,7 @@ static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
 	if (cksum == 0)
 		cksum = 1; /* zero checksums are not permitted */
 
-	if (cksum != expected_cksum) {
+	if (cksum != sp->hdr.cksum) {
 		aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK",
 					     RXKADSEALEDINCON);
 		goto protocol_error;
@@ -664,9 +667,9 @@ static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
 	case RXRPC_SECURITY_PLAIN:
 		return 0;
 	case RXRPC_SECURITY_AUTH:
-		return rxkad_verify_packet_1(call, skb, offset, len, seq, req);
+		return rxkad_verify_packet_1(call, skb, seq, req);
 	case RXRPC_SECURITY_ENCRYPT:
-		return rxkad_verify_packet_2(call, skb, offset, len, seq, req);
+		return rxkad_verify_packet_2(call, skb, seq, req);
 	default:
 		return -ENOANO;
 	}
@@ -677,52 +680,6 @@ static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
 	return -EPROTO;
 }
 
-/*
- * Locate the data contained in a packet that was partially encrypted.
- */
-static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
-				unsigned int *_offset, unsigned int *_len)
-{
-	struct rxkad_level1_hdr sechdr;
-
-	if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
-		BUG();
-	*_offset += sizeof(sechdr);
-	*_len = ntohl(sechdr.data_size) & 0xffff;
-}
-
-/*
- * Locate the data contained in a packet that was completely encrypted.
- */
-static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
-				unsigned int *_offset, unsigned int *_len)
-{
-	struct rxkad_level2_hdr sechdr;
-
-	if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
-		BUG();
-	*_offset += sizeof(sechdr);
-	*_len = ntohl(sechdr.data_size) & 0xffff;
-}
-
-/*
- * Locate the data contained in an already decrypted packet.
- */
-static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
-			      unsigned int *_offset, unsigned int *_len)
-{
-	switch (call->conn->params.security_level) {
-	case RXRPC_SECURITY_AUTH:
-		rxkad_locate_data_1(call, skb, _offset, _len);
-		return;
-	case RXRPC_SECURITY_ENCRYPT:
-		rxkad_locate_data_2(call, skb, _offset, _len);
-		return;
-	default:
-		return;
-	}
-}
-
 /*
  * issue a challenge
  */
@@ -1397,7 +1354,6 @@ const struct rxrpc_security rxkad = {
 	.secure_packet			= rxkad_secure_packet,
 	.verify_packet			= rxkad_verify_packet,
 	.free_call_crypto		= rxkad_free_call_crypto,
-	.locate_data			= rxkad_locate_data,
 	.issue_challenge		= rxkad_issue_challenge,
 	.respond_to_challenge		= rxkad_respond_to_challenge,
 	.verify_response		= rxkad_verify_response,
