[SRU][J:linux-gcp/J:linux-gke][PATCH v2 05/13] idpf: fix kernel panic on unknown packet types

[Ian Whitfield]

From: Joshua Hay <joshua.a.hay at intel.com>

BugLink: https://bugs.launchpad.net/bugs/2093622

In the very rare case where a packet type is unknown to the driver,
idpf_rx_process_skb_fields would return early without calling
eth_type_trans to set the skb protocol / the network layer handler.
This is especially problematic if tcpdump is running when such a
packet is received, i.e. it would cause a kernel panic.

Instead, call eth_type_trans for every single packet, even when
the packet type is unknown.

Fixes: 3a8845af66ed ("idpf: add RX splitq napi poll support")
Reported-by: Balazs Nemeth <bnemeth at redhat.com>
Signed-off-by: Joshua Hay <joshua.a.hay at intel.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg at intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel at intel.com>
Tested-by: Salvatore Daniele <sdaniele at redhat.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga at intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh at intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen at intel.com>
(cherry picked from commit dd19e827d63ac60debf117676d1126bff884bdb8)
Signed-off-by: Ian Whitfield <ian.whitfield at canonical.com>
---
 drivers/net/ethernet/intel/idpf/idpf_txrx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
index 2718f3ca723e..e0412ed1018e 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
@@ -2963,6 +2963,8 @@ static int idpf_rx_process_skb_fields(struct idpf_queue *rxq,
 	rx_ptype = le16_get_bits(rx_desc->ptype_err_fflags0,
 				 VIRTCHNL2_RX_FLEX_DESC_ADV_PTYPE_M);
 
+	skb->protocol = eth_type_trans(skb, rxq->vport->netdev);
+
 	decoded = rxq->vport->rx_ptype_lkup[rx_ptype];
 	/* If we don't know the ptype we can't do anything else with it. Just
 	 * pass it up the stack as-is.
@@ -2973,8 +2975,6 @@ static int idpf_rx_process_skb_fields(struct idpf_queue *rxq,
 	/* process RSS/hash */
 	idpf_rx_hash(rxq, skb, rx_desc, &decoded);
 
-	skb->protocol = eth_type_trans(skb, rxq->vport->netdev);
-
 	if (le16_get_bits(rx_desc->hdrlen_flags,
 			  VIRTCHNL2_RX_FLEX_DESC_ADV_RSC_M))
 		return idpf_rx_rsc(rxq, skb, rx_desc, &decoded);
-- 
2.43.0