From 7179b41bc6c738fe11acc43e750b6aa3dc4951e7 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 1 Jul 2022 09:57:19 +0200 Subject: [PATCH] xen-netfront: restore __skb_queue_tail() positioning in xennet_get_responses() commit f63c2c2032c2e3caad9add3b82cc6e91c376fd26 upstream. The commit referenced below moved the invocation past the "next" label, without any explanation. In fact this allows misbehaving backends undue control over the domain the frontend runs in, as earlier detected errors require the skb to not be freed (it may be retained for later processing via xennet_move_rx_slot(), or it may simply be unsafe to have it freed). This is CVE-2022-33743 / XSA-405. Fixes: 6c5aa6fc4def ("xen networking: add basic XDP support for xen-netfront") Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netfront.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 409ee9d97af4..074dceb1930b 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1094,8 +1094,10 @@ static int xennet_get_responses(struct netfront_queue *queue, } } rcu_read_unlock(); -next: + __skb_queue_tail(list, skb); + +next: if (!(rx->flags & XEN_NETRXF_more_data)) break;