Wind River Support Network

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.
Data source: kernel.org (416baaa9-dc9f-4396-8d5f-8c081fb06d67)