{"id":"CVE-2026-98402","published":"2026-10-14T14:17:51.257","lastModified":"2026-10-14T14:17:51.257","description":"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->transport_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->protocol == IPPROTO_UDP.\n2. Using skb_header_pointer() at skb_network_offset(skb) + (iph->ihl << 2)\n   to safely fetch the UDP header without assuming transport_header is set.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/04c0d35bac5122b533672a6775851dfae84e265e","tags":[]},{"url":"https://git.kernel.org/stable/c/2b32f8c3560905582fb12ed68315a6e606367a6a","tags":[]},{"url":"https://git.kernel.org/stable/c/7fcc2fe39fed1cb98a7374a113ff3800e8f9af80","tags":[]},{"url":"https://git.kernel.org/stable/c/99654b651c6d5fe865798a2adb859767905f9278","tags":[]},{"url":"https://git.kernel.org/stable/c/b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1","tags":[]},{"url":"https://git.kernel.org/stable/c/ec6d4612d1c170e1cef1fe55526471da1e81e777","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}