audit: type=1400 audit(1519809518.927:13): avc:  denied  { getopt } for  pid=6207 comm="syz-executor1" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1
==================================================================
BUG: KASAN: use-after-free in inet_shutdown+0x2e1/0x350 net/ipv4/af_inet.c:809
Read of size 4 at addr ffff8801d7e20880 by task syz-executor3/6224

CPU: 0 PID: 6224 Comm: syz-executor3 Not tainted 4.4.118-g239a415 #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 c227c9c2a473518a ffff8801c504fb58 ffffffff81d0402d
 ffffea00075f8800 ffff8801d7e20880 0000000000000000 ffff8801d7e20880
 ffff8800a96fb6d8 ffff8801c504fb90 ffffffff814fe103 ffff8801d7e20880
Call Trace:
 [<ffffffff81d0402d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0402d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff814fe103>] print_address_description+0x73/0x260 mm/kasan/report.c:252
 [<ffffffff814fe615>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff814fe615>] kasan_report+0x285/0x370 mm/kasan/report.c:408
 [<ffffffff814fe754>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428
 [<ffffffff831ceba1>] inet_shutdown+0x2e1/0x350 net/ipv4/af_inet.c:809
 [<ffffffff83463cb0>] pppol2tp_session_close+0xa0/0xe0 net/l2tp/l2tp_ppp.c:458
 [<ffffffff8345ce9f>] l2tp_tunnel_closeall+0x21f/0x3b0 net/l2tp/l2tp_core.c:1274
 [<ffffffff8345dabb>] l2tp_udp_encap_destroy+0x8b/0xf0 net/l2tp/l2tp_core.c:1300
 [<ffffffff8336bfb1>] udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1421
 [<ffffffff82dfec2b>] sk_common_release+0x6b/0x300 net/core/sock.c:2680
 [<ffffffff8336af65>] udp_lib_close+0x15/0x20 include/net/udp.h:190
 [<ffffffff831ced0a>] inet_release+0xfa/0x1d0 net/ipv4/af_inet.c:435
 [<ffffffff832f4900>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:424
 [<ffffffff82de7b2d>] sock_release+0x8d/0x1e0 net/socket.c:586
 [<ffffffff82de7c96>] sock_close+0x16/0x20 net/socket.c:1037
 [<ffffffff815235c3>] __fput+0x233/0x6d0 fs/file_table.c:208
 [<ffffffff81523ae5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118b984>] task_work_run+0x104/0x180 kernel/task_work.c:115
 [<ffffffff8100361d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100361d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:252
 [<ffffffff81007084>] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline]
 [<ffffffff81007084>] syscall_return_slowpath arch/x86/entry/common.c:348 [inline]
 [<ffffffff81007084>] do_syscall_32_irqs_on arch/x86/entry/common.c:398 [inline]
 [<ffffffff81007084>] do_fast_syscall_32+0x614/0x8a0 arch/x86/entry/common.c:459
 [<ffffffff837743ea>] sysenter_flags_fixed+0xd/0x17

Allocated by task 6224:
 [<ffffffff81035d96>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fd173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fd43d>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fd43d>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814fda12>] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554
 [<ffffffff814f90ea>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff814f90ea>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff814f90ea>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff814f90ea>] kmem_cache_alloc+0xba/0x290 mm/slub.c:2628
 [<ffffffff82dea91d>] sock_alloc_inode+0x1d/0x250 net/socket.c:250
 [<ffffffff8156f485>] alloc_inode+0x65/0x180 fs/inode.c:198
 [<ffffffff81574c57>] new_inode_pseudo+0x17/0xe0 fs/inode.c:878
 [<ffffffff82de8901>] sock_alloc+0x41/0x270 net/socket.c:555
 [<ffffffff82dedc96>] __sock_create+0xa6/0x640 net/socket.c:1141
 [<ffffffff82dee460>] sock_create net/socket.c:1217 [inline]
 [<ffffffff82dee460>] SYSC_socket net/socket.c:1247 [inline]
 [<ffffffff82dee460>] SyS_socket+0xf0/0x1b0 net/socket.c:1227
 [<ffffffff81006d91>] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline]
 [<ffffffff81006d91>] do_fast_syscall_32+0x321/0x8a0 arch/x86/entry/common.c:459
 [<ffffffff837743ea>] sysenter_flags_fixed+0xd/0x17

Freed by task 6218:
 [<ffffffff81035d96>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fd173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fda92>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fda92>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589
 [<ffffffff814fa1d7>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff814fa1d7>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff814fa1d7>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff814fa1d7>] kmem_cache_free+0xc7/0x320 mm/slub.c:2881
 [<ffffffff82dea8e6>] sock_destroy_inode+0x56/0x70 net/socket.c:280
 [<ffffffff81571bd0>] destroy_inode+0xc0/0x110 fs/inode.c:255
 [<ffffffff81571f40>] evict+0x320/0x4e0 fs/inode.c:559
 [<ffffffff81572697>] iput_final fs/inode.c:1477 [inline]
 [<ffffffff81572697>] iput+0x4a7/0x960 fs/inode.c:1504
 [<ffffffff815640ac>] dentry_iput fs/dcache.c:372 [inline]
 [<ffffffff815640ac>] __dentry_kill+0x51c/0x620 fs/dcache.c:559
 [<ffffffff815683f8>] dentry_kill fs/dcache.c:603 [inline]
 [<ffffffff815683f8>] dput.part.19+0x638/0x760 fs/dcache.c:813
 [<ffffffff8156853f>] dput+0x1f/0x30 fs/dcache.c:777
 [<ffffffff815237a1>] __fput+0x411/0x6d0 fs/file_table.c:226
 [<ffffffff81523ae5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118b984>] task_work_run+0x104/0x180 kernel/task_work.c:115
 [<ffffffff8100361d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100361d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:252
 [<ffffffff81007084>] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline]
 [<ffffffff81007084>] syscall_return_slowpath arch/x86/entry/common.c:348 [inline]
 [<ffffffff81007084>] do_syscall_32_irqs_on arch/x86/entry/common.c:398 [inline]
 [<ffffffff81007084>] do_fast_syscall_32+0x614/0x8a0 arch/x86/entry/common.c:459
 [<ffffffff837743ea>] sysenter_flags_fixed+0xd/0x17

The buggy address belongs to the object at ffff8801d7e20880
 which belongs to the cache sock_inode_cache of size 920
The buggy address is located 0 bytes inside of
 920-byte region [ffff8801d7e20880, ffff8801d7e20c18)
The buggy address belongs to the page:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 3866 at kernel/locking/lockdep.c:3190 __lock_acquire+0x23b3/0x4b50 kernel/locking/lockdep.c:3190()
DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS)