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BUG: KMSAN: uninit-value in _decode_session6+0x645/0x1650 net/ipv6/xfrm6_policy.c:149
CPU: 0 PID: 4737 Comm: syz-executor0 Not tainted 4.19.0-rc4+ #62
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x2f6/0x430 lib/dump_stack.c:113
 kmsan_report+0x183/0x2b0 mm/kmsan/kmsan.c:917
 __msan_warning+0x70/0xc0 mm/kmsan/kmsan_instr.c:500
 _decode_session6+0x645/0x1650 net/ipv6/xfrm6_policy.c:149
 __xfrm_decode_session+0x156/0x200 net/xfrm/xfrm_policy.c:2299
 xfrm_decode_session_reverse include/net/xfrm.h:1239 [inline]
 icmpv6_route_lookup net/ipv6/icmp.c:372 [inline]
 icmp6_send+0x2d01/0x3840 net/ipv6/icmp.c:551
 icmpv6_send+0xe5/0x110 net/ipv6/ip6_icmp.c:43
 ip6_link_failure+0x5c/0x310 net/ipv6/route.c:2255
 dst_link_failure include/net/dst.h:427 [inline]
 ndisc_error_report+0x106/0x1a0 net/ipv6/ndisc.c:695
 neigh_invalidate+0x35b/0x900 net/core/neighbour.c:894
 neigh_timer_handler+0xb72/0x1290 net/core/neighbour.c:980
 call_timer_fn+0x310/0x6c0 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers+0xe25/0x1280 kernel/time/timer.c:1682
 run_timer_softirq+0x2e/0x50 kernel/time/timer.c:1695
 __do_softirq+0x614/0xa72 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x20a/0x240 kernel/softirq.c:414
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:536
 smp_apic_timer_interrupt+0x64/0x90 arch/x86/kernel/apic/apic.c:1059
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:869
 </IRQ>
RIP: 0010:finish_lock_switch+0x2b/0x40 kernel/sched/core.c:2578
Code: 48 89 e5 53 48 89 fb e8 13 dc 94 00 8b b8 88 0c 00 00 48 8b 00 48 85 c0 75 12 48 89 df e8 6d d1 94 00 c6 00 00 c6 03 00 fb 5b <5d> c3 e8 2e db 94 00 eb e7 66 90 66 2e 0f 1f 84 00 00 00 00 00 55
RSP: 0018:ffff880171e9fc78 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: ffff8801e01b8ec0 RBX: ffff8801cfc65880 RCX: ffff8801e01b9ec0
RDX: ffff8801e01b9ec0 RSI: aaaaaaaaaaaab000 RDI: ffffea000cbec560
RBP: ffff880171e9fc78 R08: ffffffff7fffffff R09: 0000000000000002
R10: ffffffff7fffffff R11: 0000000000000000 R12: ffff8801bf8bbb00
R13: 0000000000000001 R14: ffff8801cfc66180 R15: ffff88021fcb9ec0
 finish_task_switch+0xe3/0x260 kernel/sched/core.c:2679
 context_switch kernel/sched/core.c:2832 [inline]
 __schedule+0x792/0x8e0 kernel/sched/core.c:3479
 schedule+0x1bc/0x2d0 kernel/sched/core.c:3523
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x3e3/0xb90 kernel/time/hrtimer.c:1688
 hrtimer_nanosleep kernel/time/hrtimer.c:1742 [inline]
 __do_sys_nanosleep kernel/time/hrtimer.c:1776 [inline]
 __se_sys_nanosleep+0x49b/0x690 kernel/time/hrtimer.c:1763
 __x64_sys_nanosleep+0x3e/0x60 kernel/time/hrtimer.c:1763
 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x483070
Code: 00 00 48 c7 c0 d4 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb be 66 0f 1f 44 00 00 83 3d 01 34 5c 00 00 75 14 b8 23 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 f4 f8 f8 ff c3 48 83 ec 08 e8 ba 70 fd ff
RSP: 002b:0000000000a3fd78 EFLAGS: 00000246 ORIG_RAX: 0000000000000023
RAX: ffffffffffffffda RBX: 000000000006933f RCX: 0000000000483070
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000a3fd80
RBP: 000000000000037a R08: 0000000000000001 R09: 0000000001f17940
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 000000000006915b R14: 00000000000000ee R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:180
 kmsan_kmalloc+0x98/0x100 mm/kmsan/kmsan_hooks.c:93
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan_hooks.c:102
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2727 [inline]
 __kmalloc_node_track_caller+0xba6/0x13f0 mm/slub.c:4360
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x40d/0xe50 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:996 [inline]
 __ip6_append_data+0x3c5e/0x51a0 net/ipv6/ip6_output.c:1427
 ip6_append_data+0x3d8/0x670 net/ipv6/ip6_output.c:1589
 rawv6_sendmsg+0x2ac7/0x5680 net/ipv6/raw.c:926
 inet_sendmsg+0x4c5/0x7d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114
 __sys_sendmsg net/socket.c:2152 [inline]
 __do_sys_sendmsg net/socket.c:2161 [inline]
 __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159
 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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