From: Florian Westphal <[email protected]>
commit a2f57827bf7c695b8c72dc4511cae8e86582369d upstream.
__ip_vs_get_out_rt() calls skb_ensure_writable() which may
reallocate skb->head.
Fixes: 8d8e20e2d7bb ("ipvs: Decrement ttl")
Cc: [email protected]
Assisted-by: Claude:claude-sonnet-4-6
Acked-by: Julian Anastasov <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
[Denis Arefev: adapted for 5.10/6.1: keep EnterFunction/LeaveFunction
instrumentation]
Signed-off-by: Denis Arefev <[email protected]>
---
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
