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BUG: KMSAN: uninit-value in decode_session6 net/xfrm/xfrm_policy.c:3407 [inline]
BUG: KMSAN: uninit-value in __xfrm_decode_session+0x10f8/0x3430 net/xfrm/xfrm_policy.c:3482
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf8/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 decode_session6 net/xfrm/xfrm_policy.c:3407 [inline]
 __xfrm_decode_session+0x10f8/0x3430 net/xfrm/xfrm_policy.c:3482
 xfrm_decode_session include/net/xfrm.h:1137 [inline]
 vti6_tnl_xmit+0x8b8/0x2780 net/ipv6/ip6_vti.c:535
 __netdev_start_xmit include/linux/netdevice.h:4447 [inline]
 netdev_start_xmit include/linux/netdevice.h:4461 [inline]
 xmit_one net/core/dev.c:3420 [inline]
 dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3436
 sch_direct_xmit+0x515/0x18c0 net/sched/sch_generic.c:314
 qdisc_restart net/sched/sch_generic.c:377 [inline]
 __qdisc_run+0x15de/0x3350 net/sched/sch_generic.c:385
 __dev_xmit_skb net/core/dev.c:3677 [inline]
 __dev_queue_xmit+0x2335/0x4280 net/core/dev.c:3982
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4046
 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x2129/0x2670 net/ipv6/ip6_output.c:116
 __ip6_finish_output+0x83d/0x8f0 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x2db/0x420 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 mld_sendpack+0xebd/0x13d0 net/ipv6/mcast.c:1682
 mld_send_cr net/ipv6/mcast.c:1978 [inline]
 mld_ifc_timer_expire+0x1181/0x1790 net/ipv6/mcast.c:2477
 call_timer_fn+0x232/0x530 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers+0xd60/0x1270 kernel/time/timer.c:1773
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 run_ksoftirqd+0x25/0x40 kernel/softirq.c:607
 smpboot_thread_fn+0x4a3/0x990 kernel/smpboot.c:165
 kthread+0x4b5/0x4f0 kernel/kthread.c:256
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144
 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:307 [inline]
 kmsan_alloc_page+0x134/0x310 mm/kmsan/kmsan_shadow.c:336
 __alloc_pages_nodemask+0x1421/0x5fd0 mm/page_alloc.c:4800
 alloc_pages_current+0x68d/0x9a0 mm/mempolicy.c:2207
 alloc_pages include/linux/gfp.h:534 [inline]
 alloc_slab_page+0x111/0x12f0 mm/slub.c:1511
 allocate_slab mm/slub.c:1656 [inline]
 new_slab+0x2cc/0x1120 mm/slub.c:1722
 new_slab_objects mm/slub.c:2473 [inline]
 ___slab_alloc+0x1423/0x1fb0 mm/slub.c:2624
 __slab_alloc mm/slub.c:2664 [inline]
 slab_alloc_node mm/slub.c:2738 [inline]
 __kmalloc_node_track_caller+0xc9d/0x11f0 mm/slub.c:4382
 __kmalloc_reserve net/core/skbuff.c:141 [inline]
 pskb_expand_head+0x214/0x1b00 net/core/skbuff.c:1628
 netlink_trim+0x361/0x3b0 net/netlink/af_netlink.c:1284
 netlink_broadcast_filtered+0x146/0x1da0 net/netlink/af_netlink.c:1489
 netlink_broadcast net/netlink/af_netlink.c:1534 [inline]
 nlmsg_multicast include/net/netlink.h:968 [inline]
 nlmsg_notify+0x20b/0x470 net/netlink/af_netlink.c:2520
 rtnl_notify net/core/rtnetlink.c:737 [inline]
 rtmsg_ifinfo_send net/core/rtnetlink.c:3693 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:3708 [inline]
 rtmsg_ifinfo+0x1e9/0x260 net/core/rtnetlink.c:3714
 register_netdevice+0x30bd/0x31b0 net/core/dev.c:9359
 register_netdev+0x93/0xd0 net/core/dev.c:9438
 ip6_tnl_init_net+0x4a3/0x7b0 net/ipv6/ip6_tunnel.c:2244
 ops_init+0x2d3/0x730 net/core/net_namespace.c:137
 setup_net+0x28e/0x12a0 net/core/net_namespace.c:335
 copy_net_ns+0x551/0xa70 net/core/net_namespace.c:476
 create_new_namespaces+0x8d8/0xe30 kernel/nsproxy.c:103
 unshare_nsproxy_namespaces+0x25e/0x340 kernel/nsproxy.c:202
 ksys_unshare+0x883/0x1110 kernel/fork.c:2937
 __do_sys_unshare kernel/fork.c:3005 [inline]
 __se_sys_unshare+0x41/0x60 kernel/fork.c:3003
 __x64_sys_unshare+0x32/0x50 kernel/fork.c:3003
 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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