From 93ccaf1c26e2133396173b76a071e59024daa622 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 7 Oct 2026 17:57:32 +0000 Subject: [PATCH] xen/netfront: don't leak the skb when xennet_fill_frags() fails When a response chain has more slots than fit in the skb's frags, xennet_fill_frags() returns an error and xennet_poll() jumps to its error path. That path moves what's left on tmpq to errq to be freed, but the skb being filled was already dequeued from tmpq, so it's never freed. Each chain that overflows leaks the skb and the pages attached to it as frags, and the backend decides how many slots it sends. Put the skb back on tmpq before taking the error path, like the xennet_set_skb_gso() failure just above it does. Fixes: ad4f15dc2c70 ("xen/netfront: don't bug in case of too many frags") Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik Reviewed-by: Juergen Gross Link: https://patch.msgid.link/20261007-b4-xen-netfront-fill-frags-leak-v1-1-a8a01ff9cd52@toxicpanda.com Signed-off-by: Jakub Kicinski --- 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 d269457e839e..fdcb91042f29 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1346,8 +1346,10 @@ err: skb->data_len = rx->status; skb->len += rx->status; - if (unlikely(xennet_fill_frags(queue, skb, &tmpq))) + if (unlikely(xennet_fill_frags(queue, skb, &tmpq))) { + __skb_queue_head(&tmpq, skb); goto err; + } if (rx->flags & XEN_NETRXF_csum_blank) skb->ip_summed = CHECKSUM_PARTIAL;