[PATCH 5.10/6.1] ipvs: reload ip header after head reallocation
From: Denis Arefev <hidden>
Date: 2026-08-28 09:05:04
Also in:
lkml, lvs-devel, netfilter-devel, stable
Subsystem:
ipvs, netfilter, networking [general], the rest · Maintainers:
Simon Horman, Julian Anastasov, Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Florian Westphal <fw@strlen.de>
commit a2f57827bf7c695b8c72dc4511cae8e86582369d upstream.
__ip_vs_get_out_rt() calls skb_ensure_writable() which may
reallocate skb->head.
Fixes: 8d8e20e2d7bb ("ipvs: Decrement ttl")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-sonnet-4-6
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
[Denis Arefev: adapted for 5.10/6.1: keep EnterFunction/LeaveFunction
instrumentation]
Signed-off-by: Denis Arefev <redacted>
---
Backport fix for CVE-2026-68476
Link: https://nvd.nist.gov/vuln/detail/CVE-2026-68476
---
net/netfilter/ipvs/ip_vs_xmit.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 9e199f00eea7..29ca141e3795 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c@@ -718,15 +718,13 @@ int ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh) { - struct iphdr *iph = ip_hdr(skb); - EnterFunction(10); - if (__ip_vs_get_out_rt(cp->ipvs, cp->af, skb, NULL, iph->daddr, - IP_VS_RT_MODE_NON_LOCAL, NULL, ipvsh) < 0) + if (__ip_vs_get_out_rt(cp->ipvs, cp->af, skb, NULL, ip_hdr(skb)->daddr, + IP_VS_RT_MODE_NON_LOCAL, NULL, ipvsh) < 0) goto tx_error; - ip_send_check(iph); + ip_send_check(ip_hdr(skb)); /* Another hack: avoid icmp_send in ip_fragment */ skb->ignore_df = 1;
--
2.43.0