From: <shiming.cheng@mediatek.com>
To: <willemdebruijn.kernel@gmail.com>, <edumazet@google.com>,
<davem@davemloft.net>, <kuba@kernel.org>, <pabeni@redhat.com>,
<matthias.bgg@gmail.com>
Cc: <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
<shiming.cheng@mediatek.com>, Lena Wang <lena.wang@mediatek.com>
Subject: [PATCH net] net: drop pulled SKB_GSO_FRAGLIST skb
Date: Sun, 28 Apr 2024 22:30:10 +0800 [thread overview]
Message-ID: <20240428143010.18719-1-shiming.cheng@mediatek.com> (raw)
From: Shiming Cheng <shiming.cheng@mediatek.com>
A SKB_GSO_FRAGLIST skb without GSO_BY_FRAGS is
expected to have all segments except the last
to be gso_size long. If this does not hold, the
skb has been modified and the fraglist gso integrity
is lost. Drop the packet, as it cannot be segmented
correctly by skb_segment_list.
The skb could be salvaged. By linearizing, dropping
the SKB_GSO_FRAGLIST bit and entering the normal
skb_segment path rather than the skb_segment_list path.
That choice is currently made in the protocol caller,
__udp_gso_segment. It's not trivial to add such a
backup path here. So let's add this backstop against
kernel crashes.
Fixes: 3a1296a38d0c ("net: Support GRO/GSO fraglist chaining.")
Signed-off-by: Shiming Cheng <shiming.cheng@mediatek.com>
Signed-off-by: Lena Wang <lena.wang@mediatek.com>
---
net/core/skbuff.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index b99127712e67..4777f5fea6c3 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4491,6 +4491,7 @@ struct sk_buff *skb_segment_list(struct sk_buff *skb,
{
struct sk_buff *list_skb = skb_shinfo(skb)->frag_list;
unsigned int tnl_hlen = skb_tnl_header_len(skb);
+ unsigned int mss = skb_shinfo(skb)->gso_size;
unsigned int delta_truesize = 0;
unsigned int delta_len = 0;
struct sk_buff *tail = NULL;
@@ -4504,6 +4505,9 @@ struct sk_buff *skb_segment_list(struct sk_buff *skb,
if (err)
goto err_linearize;
+ if (mss != GSO_BY_FRAGS && mss != skb_headlen(skb))
+ return ERR_PTR(-EFAULT);
+
skb_shinfo(skb)->frag_list = NULL;
while (list_skb) {
--
2.18.0
next reply other threads:[~2024-04-28 14:30 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-28 14:30 shiming.cheng [this message]
2024-04-29 13:25 ` [PATCH net] net: drop pulled SKB_GSO_FRAGLIST skb Willem de Bruijn
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