==================================================================
BUG: KASAN: slab-out-of-bounds in __ptr_ring_produce include/linux/ptr_ring.h:107 [inline]
BUG: KASAN: slab-out-of-bounds in ptr_ring_produce include/linux/ptr_ring.h:130 [inline]
BUG: KASAN: slab-out-of-bounds in skb_array_produce include/linux/skb_array.h:48 [inline]
BUG: KASAN: slab-out-of-bounds in tun_net_xmit+0x10b8/0x1180 drivers/net/tun.c:920
Read of size 8 at addr ffff8801ce0ff068 by task syz-executor.5/22239

CPU: 0 PID: 22239 Comm: syz-executor.5 Not tainted 4.9.141+ #1
 ffff8801db6074b8 ffffffff81b42e79 ffffea0007383fc0 ffff8801ce0ff068
 0000000000000000 ffff8801ce0ff068 ffff8801d9daeb88 ffff8801db6074f0
 ffffffff815009b8 ffff8801ce0ff068 0000000000000008 0000000000000000
Call Trace:
 <IRQ> [  520.021011]  [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  520.021011]  [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff815009b8>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81500dc2>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81500dc2>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff814f3074>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff81ed4ad8>] __ptr_ring_produce include/linux/ptr_ring.h:107 [inline]
 [<ffffffff81ed4ad8>] ptr_ring_produce include/linux/ptr_ring.h:130 [inline]
 [<ffffffff81ed4ad8>] skb_array_produce include/linux/skb_array.h:48 [inline]
 [<ffffffff81ed4ad8>] tun_net_xmit+0x10b8/0x1180 drivers/net/tun.c:920
 [<ffffffff82314c67>] __netdev_start_xmit include/linux/netdevice.h:4069 [inline]
 [<ffffffff82314c67>] netdev_start_xmit include/linux/netdevice.h:4078 [inline]
 [<ffffffff82314c67>] xmit_one net/core/dev.c:2977 [inline]
 [<ffffffff82314c67>] dev_hard_start_xmit+0x197/0x8b0 net/core/dev.c:2993
 [<ffffffff82395173>] sch_direct_xmit+0x2b3/0x580 net/sched/sch_generic.c:182
 [<ffffffff82316bae>] __dev_xmit_skb net/core/dev.c:3173 [inline]
 [<ffffffff82316bae>] __dev_queue_xmit+0x152e/0x1b90 net/core/dev.c:3441
 [<ffffffff82317227>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3506
 [<ffffffff8232f395>] neigh_direct_output+0x15/0x20 net/core/neighbour.c:1365
 [<ffffffff8269132e>] dst_neigh_output include/net/dst.h:470 [inline]
 [<ffffffff8269132e>] ip6_finish_output2+0xb0e/0x1d10 net/ipv6/ip6_output.c:119
 [<ffffffff826a1e74>] ip6_finish_output+0x334/0x980 net/ipv6/ip6_output.c:145
 [<ffffffff826a26aa>] NF_HOOK_COND include/linux/netfilter.h:246 [inline]
 [<ffffffff826a26aa>] ip6_output+0x1ea/0x6d0 net/ipv6/ip6_output.c:162
 [<ffffffff8271dbae>] dst_output include/net/dst.h:507 [inline]
 [<ffffffff8271dbae>] NF_HOOK_THRESH include/linux/netfilter.h:232 [inline]
 [<ffffffff8271dbae>] NF_HOOK include/linux/netfilter.h:255 [inline]
 [<ffffffff8271dbae>] mld_sendpack+0xa1e/0xf80 net/ipv6/mcast.c:1659
 [<ffffffff827252ba>] mld_send_cr net/ipv6/mcast.c:1955 [inline]
 [<ffffffff827252ba>] mld_ifc_timer_expire+0x3ba/0x7b0 net/ipv6/mcast.c:2455
 [<ffffffff81262a43>] call_timer_fn+0x163/0x6e0 kernel/time/timer.c:1319
 [<ffffffff812631f4>] expire_timers+0x234/0x580 kernel/time/timer.c:1359
 [<ffffffff81263748>] __run_timers kernel/time/timer.c:1674 [inline]
 [<ffffffff81263748>] run_timer_softirq+0x208/0x5e0 kernel/time/timer.c:1687
 [<ffffffff8281cb9e>] __do_softirq+0x20e/0x964 kernel/softirq.c:288
 [<ffffffff8281875c>] do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:843
 <EOI> [  520.406080]  [<ffffffff810efa62>] do_softirq.part.1+0x62/0x70 kernel/softirq.c:332
 [<ffffffff810efb46>] do_softirq kernel/softirq.c:324 [inline]
 [<ffffffff810efb46>] __local_bh_enable_ip+0xd6/0xe0 kernel/softirq.c:185
 [<ffffffff82316321>] local_bh_enable include/linux/bottom_half.h:31 [inline]
 [<ffffffff82316321>] rcu_read_unlock_bh include/linux/rcupdate.h:971 [inline]
 [<ffffffff82316321>] __dev_queue_xmit+0xca1/0x1b90 net/core/dev.c:3500
 [<ffffffff82317227>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3506
 [<ffffffff827d860d>] packet_snd net/packet/af_packet.c:2962 [inline]
 [<ffffffff827d860d>] packet_sendmsg+0x1edd/0x4520 net/packet/af_packet.c:2987
 [<ffffffff822a063b>] sock_sendmsg_nosec net/socket.c:648 [inline]
 [<ffffffff822a063b>] sock_sendmsg+0xbb/0x110 net/socket.c:658
 [<ffffffff822a0a83>] kernel_sendmsg+0x43/0x50 net/socket.c:666
 [<ffffffff822ab2c2>] sock_no_sendpage+0x112/0x150 net/core/sock.c:2334
 [<ffffffff822a0313>] kernel_sendpage+0x93/0xf0 net/socket.c:3334
 [<ffffffff822a03fc>] sock_sendpage+0x8c/0xc0 net/socket.c:802
 [<ffffffff815a98c6>] pipe_to_sendpage+0x266/0x330 fs/splice.c:470
 [<ffffffff815ad926>] splice_from_pipe_feed fs/splice.c:521 [inline]
 [<ffffffff815ad926>] __splice_from_pipe+0x316/0x710 fs/splice.c:645
 [<ffffffff815af439>] splice_from_pipe+0xf9/0x170 fs/splice.c:680
 [<ffffffff815af4ec>] generic_splice_sendpage+0x3c/0x50 fs/splice.c:851
 [<ffffffff815a9ab8>] do_splice_from fs/splice.c:870 [inline]
 [<ffffffff815a9ab8>] direct_splice_actor+0x128/0x190 fs/splice.c:1037
 [<ffffffff815ab6c1>] splice_direct_to_actor+0x2c1/0x7e0 fs/splice.c:992
 [<ffffffff815abd83>] do_splice_direct+0x1a3/0x270 fs/splice.c:1080
 [<ffffffff8150d780>] do_sendfile+0x4f0/0xc30 fs/read_write.c:1393
 [<ffffffff8150f864>] SYSC_sendfile64 fs/read_write.c:1454 [inline]
 [<ffffffff8150f864>] SyS_sendfile64+0x144/0x160 fs/read_write.c:1440
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Allocated by task 22249:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack mm/kasan/kasan.c:505 [inline]
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:609
 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:594
 __kmalloc+0x12f/0x310 mm/slub.c:3741
 kmalloc_array include/linux/slab.h:582 [inline]
 kcalloc include/linux/slab.h:593 [inline]
 __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:356 [inline]
 ptr_ring_resize_multiple include/linux/ptr_ring.h:445 [inline]
 skb_array_resize_multiple include/linux/skb_array.h:169 [inline]
 tun_queue_resize drivers/net/tun.c:2523 [inline]
 tun_device_event+0x3e0/0xa00 drivers/net/tun.c:2541
 notifier_call_chain+0xb4/0x1d0 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x55/0x70 net/core/dev.c:1647
 call_netdevice_notifiers+0x70/0xa0 net/core/dev.c:1663
 do_setlink+0xc55/0x2ef0 net/core/rtnetlink.c:2052
 rtnl_group_changelink net/core/rtnetlink.c:2423 [inline]
 rtnl_newlink+0xbd0/0x1550 net/core/rtnetlink.c:2571
 rtnetlink_rcv_msg+0x49c/0x650 net/core/rtnetlink.c:4078
 netlink_rcv_skb+0x145/0x370 net/netlink/af_netlink.c:2365
 rtnetlink_rcv+0x2a/0x40 net/core/rtnetlink.c:4084
 netlink_unicast_kernel net/netlink/af_netlink.c:1285 [inline]
 netlink_unicast+0x4d8/0x6d0 net/netlink/af_netlink.c:1311
 netlink_sendmsg+0x694/0xc30 net/netlink/af_netlink.c:1859
 sock_sendmsg_nosec net/socket.c:648 [inline]
 sock_sendmsg+0xbb/0x110 net/socket.c:658
 ___sys_sendmsg+0x6fc/0x840 net/socket.c:1982
 __sys_sendmsg+0xd9/0x190 net/socket.c:2016
 SYSC_sendmsg net/socket.c:2027 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2023
 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Freed by task 19162:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack mm/kasan/kasan.c:505 [inline]
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:582
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kfree+0xfb/0x310 mm/slub.c:3878
 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:4933
 security_tun_dev_free_security+0x4e/0x90 security/security.c:1416
 tun_free_netdev+0xb3/0xf0 drivers/net/tun.c:1551
 netdev_run_todo+0x4f9/0x770 net/core/dev.c:7577
 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:104
 tun_detach drivers/net/tun.c:586 [inline]
 tun_chr_close+0x49/0x60 drivers/net/tun.c:2392
 __fput+0x263/0x700 fs/file_table.c:208
 ____fput+0x15/0x20 fs/file_table.c:244
 task_work_run+0x10c/0x180 kernel/task_work.c:116
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x129/0x150 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:263 [inline]
 do_syscall_64+0x3e2/0x550 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the object at ffff8801ce0ff060
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes to the right of
 8-byte region [ffff8801ce0ff060, ffff8801ce0ff068)
The buggy address belongs to the page:
page:ffffea0007383fc0 count:1 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000080(slab)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ce0fef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801ce0fef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801ce0ff000: 00 fc fc 00 fc fc 00 fc fc 00 fc fc 00 fc fc fb
                                                          ^
 ffff8801ce0ff080: fc fc fb fc fc fb fc fc fb fc fc fb fc fc fb fc
 ffff8801ce0ff100: fc fb fc fc 00 fc fc fb fc fc fb fc fc fb fc fc
==================================================================