Files
xiaomi-ax3600/target/linux/generic/backport-6.6/622-v6.12-net-gso-fix-tcp-fraglist-segmentation-after-pull-fro.patch
Mieczyslaw Nalewaj 456b7a5d48 kernel/generic: Restore kernel files for v6.6
This is an automatically generated commit which aids following Kernel patch
history, as git will see the move and copy as a rename thus defeating the
purpose.

For the original discussion see:
https://lists.openwrt.org/pipermail/openwrt-devel/2023-October/041673.html

Signed-off-by: Mieczyslaw Nalewaj <namiltd@yahoo.com>
Link: https://github.com/openwrt/openwrt/pull/16547
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
2025-04-30 16:26:29 +02:00

81 lines
3.0 KiB
Diff

From 17bd3bd82f9f79f3feba15476c2b2c95a9b11ff8 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Thu, 26 Sep 2024 10:53:14 +0200
Subject: [PATCH] net: gso: fix tcp fraglist segmentation after pull from
frag_list
Detect tcp gso fraglist skbs with corrupted geometry (see below) and
pass these to skb_segment instead of skb_segment_list, as the first
can segment them correctly.
Valid SKB_GSO_FRAGLIST skbs
- consist of two or more segments
- the head_skb holds the protocol headers plus first gso_size
- one or more frag_list skbs hold exactly one segment
- all but the last must be gso_size
Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can
modify these skbs, breaking these invariants.
In extreme cases they pull all data into skb linear. For TCP, this
causes a NULL ptr deref in __tcpv4_gso_segment_list_csum at
tcp_hdr(seg->next).
Detect invalid geometry due to pull, by checking head_skb size.
Don't just drop, as this may blackhole a destination. Convert to be
able to pass to regular skb_segment.
Approach and description based on a patch by Willem de Bruijn.
Link: https://lore.kernel.org/netdev/20240428142913.18666-1-shiming.cheng@mediatek.com/
Link: https://lore.kernel.org/netdev/20240922150450.3873767-1-willemdebruijn.kernel@gmail.com/
Fixes: bee88cd5bd83 ("net: add support for segmenting TCP fraglist GSO packets")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240926085315.51524-1-nbd@nbd.name
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
net/ipv4/tcp_offload.c | 10 ++++++++--
net/ipv6/tcpv6_offload.c | 10 ++++++++--
2 files changed, 16 insertions(+), 4 deletions(-)
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -104,8 +104,14 @@ static struct sk_buff *tcp4_gso_segment(
if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
return ERR_PTR(-EINVAL);
- if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)
- return __tcp4_gso_segment_list(skb, features);
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST) {
+ struct tcphdr *th = tcp_hdr(skb);
+
+ if (skb_pagelen(skb) - th->doff * 4 == skb_shinfo(skb)->gso_size)
+ return __tcp4_gso_segment_list(skb, features);
+
+ skb->ip_summed = CHECKSUM_NONE;
+ }
if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
const struct iphdr *iph = ip_hdr(skb);
--- a/net/ipv6/tcpv6_offload.c
+++ b/net/ipv6/tcpv6_offload.c
@@ -158,8 +158,14 @@ static struct sk_buff *tcp6_gso_segment(
if (!pskb_may_pull(skb, sizeof(*th)))
return ERR_PTR(-EINVAL);
- if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)
- return __tcp6_gso_segment_list(skb, features);
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST) {
+ struct tcphdr *th = tcp_hdr(skb);
+
+ if (skb_pagelen(skb) - th->doff * 4 == skb_shinfo(skb)->gso_size)
+ return __tcp6_gso_segment_list(skb, features);
+
+ skb->ip_summed = CHECKSUM_NONE;
+ }
if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
const struct ipv6hdr *ipv6h = ipv6_hdr(skb);