{"id":"CVE-2026-98402","summary":"net: icmp: avoid invalid transport header access in icmp_send tracepoint","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: icmp: avoid invalid transport header access in icmp_send tracepoint\n\nsyzbot reported a WARNING triggered by DEBUG_NET_WARN_ON_ONCE():\n\n WARNING: at skb_transport_header include/linux/skbuff.h:3087 [inline]\n WARNING: at udp_hdr include/linux/udp.h:23 [inline]\n WARNING: at do_trace_event_raw_event_icmp_send include/trace/events/icmp.h:30 [inline]\n WARNING: at trace_event_raw_event_icmp_send+0x48c/0x6ec include/trace/events/icmp.h:11\n Call trace:\n  skb_transport_header include/linux/skbuff.h:3087 [inline]\n  udp_hdr include/linux/udp.h:23 [inline]\n  do_trace_event_raw_event_icmp_send include/trace/events/icmp.h:30 [inline]\n  trace_event_raw_event_icmp_send+0x48c/0x6ec include/trace/events/icmp.h:11\n  __traceiter_icmp_send include/trace/events/icmp.h:11 [inline]\n  __do_trace_icmp_send include/trace/events/icmp.h:11 [inline]\n  trace_icmp_send+0x320/0x49c include/trace/events/icmp.h:11\n  __icmp_send+0xcfc/0x11d8 net/ipv4/icmp.c:1013\n  ipv4_send_dest_unreach net/ipv4/route.c:1280 [inline]\n  ipv4_link_failure+0x57c/0x8dc net/ipv4/route.c:1287\n  dst_link_failure include/net/dst.h:438 [inline]\n  vti_tunnel_xmit+0xe40/0x17a4 net/ipv4/ip_vti.c:307\n\nTP_fast_assign() unconditionally calls udp_hdr(skb) before checking\nwhether the packet is UDP. Furthermore, __icmp_send() can be invoked\nfrom paths (e.g., link failures, ARP errors, forwarding, AF_PACKET)\nwhere skb-\u003etransport_header was never initialized (~0U).\n\nUnder CONFIG_DEBUG_NET=y, calling skb_transport_header(skb) triggers\nDEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)).\n\nFix this by:\n1. Only parsing transport info when iph-\u003eprotocol == IPPROTO_UDP.\n2. Using skb_header_pointer() at skb_network_offset(skb) + (iph-\u003eihl \u003c\u003c 2)\n   to safely fetch the UDP header without assuming transport_header is set.","modified":"2026-10-15T02:47:42.145168508Z","published":"2026-10-14T13:26:02.321Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98402.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/04c0d35bac5122b533672a6775851dfae84e265e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2b32f8c3560905582fb12ed68315a6e606367a6a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7fcc2fe39fed1cb98a7374a113ff3800e8f9af80"},{"type":"WEB","url":"https://git.kernel.org/stable/c/99654b651c6d5fe865798a2adb859767905f9278"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ec6d4612d1c170e1cef1fe55526471da1e81e777"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98402.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98402"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"524c341cb16a8d5318d2ffacf6fe160271a18743"},{"fixed":"ec6d4612d1c170e1cef1fe55526471da1e81e777"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"21b28f97e621cba196fb32c576734d216a8a79c9"},{"fixed":"99654b651c6d5fe865798a2adb859767905f9278"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"db3efdcf70c752e8a8deb16071d8e693c3ef8746"},{"fixed":"b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1"},{"fixed":"04c0d35bac5122b533672a6775851dfae84e265e"},{"fixed":"2b32f8c3560905582fb12ed68315a6e606367a6a"},{"fixed":"7fcc2fe39fed1cb98a7374a113ff3800e8f9af80"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.1.130"},{"fixed":"6.1.189"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.6.81"},{"fixed":"6.6.158"}]}],"versions":["v6.1.188","v6.1.187","v6.1.186","v6.1.185","v6.1.184","v6.1.183","v6.1.182","v6.1.181","v6.1.180","v6.1.179","v6.1.178","v6.1.177","v6.1.176","v6.1.175","v6.1.174","v6.1.173","v6.1.172","v6.1.171","v6.1.170","v6.1.169","v6.1.168","v6.1.167","v6.1.166","v6.1.165","v6.1.164","v6.1.163","v6.1.162","v6.1.161","v6.1.160","v6.1.159","v6.1.158","v6.1.157","v6.1.156","v6.1.155","v6.1.154","v6.1.153","v6.1.152","v6.1.151","v6.1.150","v6.1.149","v6.1.148","v6.1.147","v6.1.146","v6.1.145","v6.1.144","v6.1.143","v6.1.142","v6.1.141","v6.1.140","v6.1.139","v6.1.138","v6.1.137","v6.1.136","v6.1.135","v6.1.134","v6.1.133","v6.1.132","v6.1.131","v6.1.130","v6.6.157","v6.6.156","v6.6.155","v6.6.154","v6.6.153","v6.6.152","v6.6.151","v6.6.150","v6.6.149","v6.6.148","v6.6.147","v6.6.146","v6.6.145","v6.6.144","v6.6.143","v6.6.142","v6.6.141","v6.6.140","v6.6.139","v6.6.138","v6.6.137","v6.6.136","v6.6.135","v6.6.134","v6.6.133","v6.6.132","v6.6.131","v6.6.130","v6.6.129","v6.6.128","v6.6.127","v6.6.126","v6.6.125","v6.6.124","v6.6.123","v6.6.122","v6.6.121","v6.6.120","v6.6.119","v6.6.118","v6.6.117","v6.6.116","v6.6.115","v6.6.114","v6.6.113","v6.6.112","v6.6.111","v6.6.110","v6.6.109","v6.6.108","v6.6.107","v6.6.106","v6.6.105","v6.6.104","v6.6.103","v6.6.102","v6.6.101","v6.6.100","v6.6.99","v6.6.98","v6.6.97","v6.6.96","v6.6.95","v6.6.94","v6.6.93","v6.6.92","v6.6.91","v6.6.90","v6.6.89","v6.6.88","v6.6.87","v6.6.86","v6.6.85","v6.6.84","v6.6.83","v6.6.82","v6.6.81"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98402.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.10.0"},{"fixed":"6.18.53"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"7.2.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98402.json"}}],"schema_version":"1.9.0"}