From: Jibin Zhang <jibin.zhang@mediatek.com> stable inclusion from stable-v6.12.69 commit 3e62db1e3140449608975e29e0979cc5f3b1cc07 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13704 CVE: CVE-2026-23154 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 426ca15c7f6cb6562a081341ca88893a50c59fa2 upstream. This patch enhances GSO segment handling by properly checking the SKB_GSO_DODGY flag for frag_list GSO packets, addressing low throughput issues observed when a station accesses IPv4 servers via hotspots with an IPv6-only upstream interface. Specifically, it fixes a bug in GSO segmentation when forwarding GRO packets containing a frag_list. The function skb_segment_list cannot correctly process GRO skbs that have been converted by XLAT, since XLAT only translates the header of the head skb. Consequently, skbs in the frag_list may remain untranslated, resulting in protocol inconsistencies and reduced throughput. To address this, the patch explicitly sets the SKB_GSO_DODGY flag for GSO packets in XLAT's IPv4/IPv6 protocol translation helpers (bpf_skb_proto_4_to_6 and bpf_skb_proto_6_to_4). This marks GSO packets as potentially modified after protocol translation. As a result, GSO segmentation will avoid using skb_segment_list and instead falls back to skb_segment for packets with the SKB_GSO_DODGY flag. This ensures that only safe and fully translated frag_list packets are processed by skb_segment_list, resolving protocol inconsistencies and improving throughput when forwarding GRO packets converted by XLAT. Signed-off-by: Jibin Zhang <jibin.zhang@mediatek.com> Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260126152114.1211-1-jibin.zhang@mediatek.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Conflicts: net/ipv4/tcp_offload.c net/ipv6/tcpv6_offload.c [conflicts due to not merge bee88cd5bd83 ("net: add support for segmenting TCP fraglist GSO packets") and 17bd3bd82f9f ("net: gso: fix tcp fraglist segmentation after pull from frag_list").] Signed-off-by: Li Xiasong <lixiasong1@huawei.com> --- net/core/filter.c | 2 ++ net/ipv4/udp_offload.c | 3 ++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index 00037445a6c6..a7af6be43624 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3340,6 +3340,7 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb) shinfo->gso_type &= ~SKB_GSO_TCPV4; shinfo->gso_type |= SKB_GSO_TCPV6; } + shinfo->gso_type |= SKB_GSO_DODGY; } bpf_skb_change_protocol(skb, ETH_P_IPV6); @@ -3370,6 +3371,7 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb) shinfo->gso_type &= ~SKB_GSO_TCPV6; shinfo->gso_type |= SKB_GSO_TCPV4; } + shinfo->gso_type |= SKB_GSO_DODGY; } bpf_skb_change_protocol(skb, ETH_P_IP); diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 9be9df2caf65..cd860d8d497b 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -352,7 +352,8 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) { /* Detect modified geometry and pass those to skb_segment. */ - if (skb_pagelen(gso_skb) - sizeof(*uh) == skb_shinfo(gso_skb)->gso_size) + if ((skb_pagelen(gso_skb) - sizeof(*uh) == skb_shinfo(gso_skb)->gso_size) && + !(skb_shinfo(gso_skb)->gso_type & SKB_GSO_DODGY)) return __udp_gso_segment_list(gso_skb, features, is_ipv6); ret = __skb_linearize(gso_skb); -- 2.34.1