From 06673c2102b3f0959302d65e07485ba3f2b94127 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Wed, 13 Jul 2022 11:19:55 +0200 Subject: xen-netfront: re-order error checks in xennet_get_responses() Check the retrieved grant reference first; there's no point trying to have xennet_move_rx_slot() move invalid data (and further defer recognition of the issue, likely making diagnosis yet more difficult). Signed-off-by: Jan Beulich Signed-off-by: Paolo Abeni --- drivers/net/xen-netfront.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 8bae9b84f045..27a11cc08c61 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1043,16 +1043,6 @@ static int xennet_get_responses(struct netfront_queue *queue, } for (;;) { - if (unlikely(rx->status < 0 || - rx->offset + rx->status > XEN_PAGE_SIZE)) { - if (net_ratelimit()) - dev_warn(dev, "rx->offset: %u, size: %d\n", - rx->offset, rx->status); - xennet_move_rx_slot(queue, skb, ref); - err = -EINVAL; - goto next; - } - /* * This definitely indicates a bug, either in this driver or in * the backend driver. In future this should flag the bad @@ -1066,6 +1056,16 @@ static int xennet_get_responses(struct netfront_queue *queue, goto next; } + if (unlikely(rx->status < 0 || + rx->offset + rx->status > XEN_PAGE_SIZE)) { + if (net_ratelimit()) + dev_warn(dev, "rx->offset: %u, size: %d\n", + rx->offset, rx->status); + xennet_move_rx_slot(queue, skb, ref); + err = -EINVAL; + goto next; + } + if (!gnttab_end_foreign_access_ref(ref)) { dev_alert(dev, "Grant still in use by backend domain\n"); -- cgit v1.2.3-58-ga151