CVE-2026-98402 is a vulnerability in Linux Kernel
Published on October 14, 2026
net: icmp: avoid invalid transport header access in icmp_send tracepoint
In the Linux kernel, the following vulnerability has been resolved:
net: icmp: avoid invalid transport header access in icmp_send tracepoint
syzbot reported a WARNING triggered by DEBUG_NET_WARN_ON_ONCE():
WARNING: at skb_transport_header include/linux/skbuff.h:3087 [inline]
WARNING: at udp_hdr include/linux/udp.h:23 [inline]
WARNING: at do_trace_event_raw_event_icmp_send include/trace/events/icmp.h:30 [inline]
WARNING: at trace_event_raw_event_icmp_send+0x48c/0x6ec include/trace/events/icmp.h:11
Call trace:
skb_transport_header include/linux/skbuff.h:3087 [inline]
udp_hdr include/linux/udp.h:23 [inline]
do_trace_event_raw_event_icmp_send include/trace/events/icmp.h:30 [inline]
trace_event_raw_event_icmp_send+0x48c/0x6ec include/trace/events/icmp.h:11
__traceiter_icmp_send include/trace/events/icmp.h:11 [inline]
__do_trace_icmp_send include/trace/events/icmp.h:11 [inline]
trace_icmp_send+0x320/0x49c include/trace/events/icmp.h:11
__icmp_send+0xcfc/0x11d8 net/ipv4/icmp.c:1013
ipv4_send_dest_unreach net/ipv4/route.c:1280 [inline]
ipv4_link_failure+0x57c/0x8dc net/ipv4/route.c:1287
dst_link_failure include/net/dst.h:438 [inline]
vti_tunnel_xmit+0xe40/0x17a4 net/ipv4/ip_vti.c:307
TP_fast_assign() unconditionally calls udp_hdr(skb) before checking
whether the packet is UDP. Furthermore, __icmp_send() can be invoked
from paths (e.g., link failures, ARP errors, forwarding, AF_PACKET)
where skb->transport_header was never initialized (~0U).
Under CONFIG_DEBUG_NET=y, calling skb_transport_header(skb) triggers
DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)).
Fix this by:
1. Only parsing transport info when iph->protocol == IPPROTO_UDP.
2. Using skb_header_pointer() at skb_network_offset(skb) + (iph->ihl << 2)
to safely fetch the UDP header without assuming transport_header is set.
Products Associated with CVE-2026-98402
Want to know whenever a new CVE is published for Linux Kernel? stack.watch will email you.
Affected Versions
Linux:- Version 524c341cb16a8d5318d2ffacf6fe160271a18743 and below ec6d4612d1c170e1cef1fe55526471da1e81e777 is affected.
- Version 21b28f97e621cba196fb32c576734d216a8a79c9 and below 99654b651c6d5fe865798a2adb859767905f9278 is affected.
- Version db3efdcf70c752e8a8deb16071d8e693c3ef8746 and below b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1 is affected.
- Version db3efdcf70c752e8a8deb16071d8e693c3ef8746 and below 04c0d35bac5122b533672a6775851dfae84e265e is affected.
- Version db3efdcf70c752e8a8deb16071d8e693c3ef8746 and below 2b32f8c3560905582fb12ed68315a6e606367a6a is affected.
- Version db3efdcf70c752e8a8deb16071d8e693c3ef8746 and below 7fcc2fe39fed1cb98a7374a113ff3800e8f9af80 is affected.
- Version 6.1.130 and below 6.1.189 is affected.
- Version 6.6.81 and below 6.6.158 is affected.
- Version 6.10 is affected.
- Before 6.10 is unaffected.
- Version 6.1.189, <= 6.1.* is unaffected.
- Version 6.6.158, <= 6.6.* is unaffected.
- Version 6.12.111, <= 6.12.* is unaffected.
- Version 6.18.53, <= 6.18.* is unaffected.
- Version 7.2.7, <= 7.2.* is unaffected.
- Version 7.3-rc2, <= * is unaffected.