CVE-2026-98402
Received
Received - Intake
Out-of-bounds Transport Header Access in Linux Kernel
Vulnerability report for CVE-2026-98402, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-14
Last updated on: 2026-10-14
Assigner: kernel.org
Description
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 524c341cb16a8d5318d2ffacf6fe160271a18743 |
| Linux | Linux | 21b28f97e621cba196fb32c576734d216a8a79c9 |
| Linux | Linux | db3efdcf70c752e8a8deb16071d8e693c3ef8746 |
| Linux | Linux | db3efdcf70c752e8a8deb16071d8e693c3ef8746 |
| Linux | Linux | db3efdcf70c752e8a8deb16071d8e693c3ef8746 |
| Linux | Linux | db3efdcf70c752e8a8deb16071d8e693c3ef8746 |
| Linux | Linux | 6.1.130 |
| Linux | Linux | 6.6.81 |
| Linux | Linux | 6.10 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
