================================================================== BUG: KMSAN: uninit-value in ipv6_skip_exthdr+0x796/0x900 net/ipv6/exthdrs_core.c:97 CPU: 0 PID: 3644 Comm: syz-executor6 Not tainted 4.16.0+ #84 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 ipv6_skip_exthdr+0x796/0x900 net/ipv6/exthdrs_core.c:97 is_ineligible net/ipv6/icmp.c:155 [inline] icmp6_send+0xec1/0x3460 net/ipv6/icmp.c:498 icmpv6_send+0xe0/0x110 net/ipv6/ip6_icmp.c:43 ip6_link_failure+0x8f/0x580 net/ipv6/route.c:2034 dst_link_failure include/net/dst.h:426 [inline] ndisc_error_report+0x101/0x1a0 net/ipv6/ndisc.c:695 neigh_invalidate+0x385/0x930 net/core/neighbour.c:883 neigh_timer_handler+0xd85/0x12d0 net/core/neighbour.c:969 call_timer_fn+0x26a/0x5a0 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0xda7/0x11c0 kernel/time/timer.c:1666 run_timer_softirq+0x43/0x70 kernel/time/timer.c:1692 __do_softirq+0x56d/0x93d kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x202/0x240 kernel/softirq.c:405 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:541 smp_apic_timer_interrupt+0x64/0x90 arch/x86/kernel/apic/apic.c:1055 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857 RIP: 0010:__msan_get_context_state+0x48/0xf0 mm/kmsan/kmsan_instr.c:692 RSP: 0000:ffff88016904f928 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff12 RAX: 0000000000000000 RBX: ffffffff8832e000 RCX: ffff880000000000 RDX: ffff8802033610f0 RSI: aaaaaaaaaaaab000 RDI: ffff880167129c80 RBP: ffff88016904f950 R08: 00000000010000c0 R09: 0000000000000002 R10: 0000000000000000 R11: ffff880169040000 R12: ffff8801bca8a0c8 R13: 0000000000000000 R14: ffff880169a51d80 R15: ffff880167129c80 memcg_kmem_put_cache+0x19/0x280 mm/memcontrol.c:2296 slab_post_alloc_hook mm/slab.h:449 [inline] slab_alloc_node mm/slub.c:2737 [inline] slab_alloc mm/slub.c:2745 [inline] kmem_cache_alloc+0x6cd/0xb90 mm/slub.c:2750 dup_mmap kernel/fork.c:451 [inline] dup_mm kernel/fork.c:1234 [inline] copy_mm kernel/fork.c:1288 [inline] copy_process+0x62fd/0x9b30 kernel/fork.c:1794 _do_fork+0x311/0xf00 kernel/fork.c:2088 SYSC_clone+0xf6/0x110 kernel/fork.c:2195 SyS_clone+0x77/0xa0 kernel/fork.c:2189 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x4539da RSP: 002b:0000000000a3ea70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000a3ea70 RCX: 00000000004539da RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000a3eab0 R08: 0000000000000001 R09: 0000000000ed7940 R10: 0000000000ed7c10 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000001380 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_save_stack mm/kmsan/kmsan.c:293 [inline] kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:526 __msan_memcpy+0x19f/0x1f0 mm/kmsan/kmsan_instr.c:470 skb_copy_bits+0x63a/0xdb0 net/core/skbuff.c:2046 __skb_header_pointer include/linux/skbuff.h:3337 [inline] skb_header_pointer include/linux/skbuff.h:3346 [inline] ipv6_skip_exthdr+0x472/0x900 net/ipv6/exthdrs_core.c:89 is_ineligible net/ipv6/icmp.c:155 [inline] icmp6_send+0xec1/0x3460 net/ipv6/icmp.c:498 icmpv6_send+0xe0/0x110 net/ipv6/ip6_icmp.c:43 ip6_link_failure+0x8f/0x580 net/ipv6/route.c:2034 dst_link_failure include/net/dst.h:426 [inline] ndisc_error_report+0x101/0x1a0 net/ipv6/ndisc.c:695 neigh_invalidate+0x385/0x930 net/core/neighbour.c:883 neigh_timer_handler+0xd85/0x12d0 net/core/neighbour.c:969 call_timer_fn+0x26a/0x5a0 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0xda7/0x11c0 kernel/time/timer.c:1666 run_timer_softirq+0x43/0x70 kernel/time/timer.c:1692 __do_softirq+0x56d/0x93d kernel/softirq.c:285 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_alloc_meta_for_pages+0x161/0x3a0 mm/kmsan/kmsan.c:814 kmsan_alloc_page+0x82/0xe0 mm/kmsan/kmsan.c:868 __alloc_pages_nodemask+0xf5b/0x5dc0 mm/page_alloc.c:4283 alloc_pages_current+0x6b5/0x970 mm/mempolicy.c:2055 alloc_pages include/linux/gfp.h:494 [inline] skb_page_frag_refill+0x3ba/0x5e0 net/core/sock.c:2208 sk_page_frag_refill+0xa4/0x340 net/core/sock.c:2228 __ip6_append_data+0x1a20/0x4bb0 net/ipv6/ip6_output.c:1503 ip6_append_data+0x40e/0x6b0 net/ipv6/ip6_output.c:1576 rawv6_sendmsg+0x2787/0x4cc0 net/ipv6/raw.c:928 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] sock_write_iter+0x3b9/0x470 net/socket.c:909 do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776 do_iter_write+0x30d/0xd40 fs/read_write.c:932 vfs_writev fs/read_write.c:977 [inline] do_writev+0x3c9/0x830 fs/read_write.c:1012 SYSC_writev+0x9b/0xb0 fs/read_write.c:1085 SyS_writev+0x56/0x80 fs/read_write.c:1082 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 ==================================================================