audit: type=1400 audit(1546747794.675:7): avc:  denied  { map } for  pid=1788 comm="syz-executor043" path="/root/syz-executor043331174" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
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BUG: KASAN: use-after-free in xfrm6_tunnel_free_spi net/ipv6/xfrm6_tunnel.c:205 [inline]
BUG: KASAN: use-after-free in xfrm6_tunnel_destroy+0x4e0/0x560 net/ipv6/xfrm6_tunnel.c:300
Read of size 8 at addr ffff8881c3da07f8 by task kworker/1:1/68

CPU: 1 PID: 68 Comm: kworker/1:1 Not tainted 4.14.91+ #3
Workqueue: events xfrm_state_gc_task
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 print_address_description+0x60/0x226 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0x88/0x2a5 mm/kasan/report.c:393

Allocated by task 1795:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551
 __kmalloc+0x143/0x340 mm/slub.c:3760
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 ops_init+0xee/0x3e0 net/core/net_namespace.c:108
 setup_net+0x22b/0x520 net/core/net_namespace.c:294
 copy_net_ns+0x19b/0x440 net/core/net_namespace.c:418
 create_new_namespaces+0x366/0x750 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xa5/0x1e0 kernel/nsproxy.c:206
 SYSC_unshare kernel/fork.c:2377 [inline]
 SyS_unshare+0x300/0x690 kernel/fork.c:2327
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289

Freed by task 374:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xb0/0x190 mm/kasan/kasan.c:524
 slab_free_hook mm/slub.c:1389 [inline]
 slab_free_freelist_hook mm/slub.c:1410 [inline]
 slab_free mm/slub.c:2966 [inline]
 kfree+0xf5/0x310 mm/slub.c:3897
 ops_free net/core/net_namespace.c:132 [inline]
 ops_free_list.part.0+0x1f9/0x330 net/core/net_namespace.c:154
 ops_free_list net/core/net_namespace.c:152 [inline]
 cleanup_net+0x466/0x860 net/core/net_namespace.c:487
 process_one_work+0x7c6/0x14e0 kernel/workqueue.c:2114
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2248
 kthread+0x310/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402

The buggy address belongs to the object at ffff8881c3da0000
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 2040 bytes inside of
 8192-byte region [ffff8881c3da0000, ffff8881c3da2000)
The buggy address belongs to the page:
page:ffffea00070f6800 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x4000000000008100(slab|head)
raw: 4000000000008100 0000000000000000 0000000000000000 0000000100030003
raw: dead000000000100 dead000000000200 ffff8881da802400 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881c3da0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881c3da0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881c3da0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff8881c3da0800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881c3da0880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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