From: Julian Anastasov <ja@ssi.bg> stable inclusion from stable-v5.10.261 commit 613ce63711b8d431bba90781f133c39a21684f87 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18235 CVE: CVE-2026-74724 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- commit b3fe4cbd583895987935a9bdad01c8f9d3a02310 upstream. Sashiko reports for more incorrect IPv6 transport offsets. The app code for TCP was assuming IPv4 network header even after the ipvsh argument was provided. This can cause problems with apps over IPv6. As for the only official app in the kernel tree (FTP) this problem is harmless because we use Netfilter to mangle the FTP ports and we do not adjust the TCP seq numbers. Also, provide correct offset of the ICMPV6 header in ip_vs_out_icmp_v6() for correct checksum checks when the IPv6 packet has extension headers. Fixes: d12e12299a69 ("ipvs: add ipv6 support to ftp") Fixes: 2a3b791e6e11 ("IPVS: Add/adjust Netfilter hook functions and helpers for v6") Cc: stable@vger.kernel.org Link: https://sashiko.dev/#/patchset/20260706101624.69471-1-zhaoyz24%40mails.tsing... Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com> --- net/netfilter/ipvs/ip_vs_app.c | 10 ++++------ net/netfilter/ipvs/ip_vs_core.c | 3 +-- 2 files changed, 5 insertions(+), 8 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_app.c b/net/netfilter/ipvs/ip_vs_app.c index fdacbc3..f9132b3 100644 --- a/net/netfilter/ipvs/ip_vs_app.c +++ b/net/netfilter/ipvs/ip_vs_app.c @@ -362,14 +362,13 @@ static inline int app_tcp_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb, struct ip_vs_iphdr *ipvsh) { int diff; - const unsigned int tcp_offset = ip_hdrlen(skb); struct tcphdr *th; __u32 seq; - if (skb_ensure_writable(skb, tcp_offset + sizeof(*th))) + if (skb_ensure_writable(skb, ipvsh->len + sizeof(*th))) return 0; - th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset); + th = (struct tcphdr *)(skb_network_header(skb) + ipvsh->len); /* * Remember seq number in case this pkt gets resized @@ -439,14 +438,13 @@ static inline int app_tcp_pkt_in(struct ip_vs_conn *cp, struct sk_buff *skb, struct ip_vs_iphdr *ipvsh) { int diff; - const unsigned int tcp_offset = ip_hdrlen(skb); struct tcphdr *th; __u32 seq; - if (skb_ensure_writable(skb, tcp_offset + sizeof(*th))) + if (skb_ensure_writable(skb, ipvsh->len + sizeof(*th))) return 0; - th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset); + th = (struct tcphdr *)(skb_network_header(skb) + ipvsh->len); /* * Remember seq number in case this pkt gets resized diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 0586011..1c2f1ab 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -1054,8 +1054,7 @@ static int ip_vs_out_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb, snet.in6 = ciph.saddr.in6; offset = ciph.len; return handle_response_icmp(AF_INET6, skb, &snet, ciph.protocol, cp, - pp, offset, sizeof(struct ipv6hdr), - hooknum); + pp, offset, ipvsh->len, hooknum); } #endif -- 2.9.5