lkml.org 
[lkml]   [2024]   [Apr]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH net] net: drop pulled SKB_GSO_FRAGLIST skb
Date
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

\
 
 \ /
  Last update: 2024-04-28 16:30    [W:0.059 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site