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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 ffff8801d2c40ad0 by task syz-executor.2/2104

CPU: 0 PID: 2104 Comm: syz-executor.2 Not tainted 4.9.141+ #1
 ffff8801db607488 ffffffff81b42e79 ffffea00074b1000 ffff8801d2c40ad0
 0000000000000000 ffff8801d2c40ad0 ffff8801c9058e08 ffff8801db6074c0
 ffffffff815009b8 ffff8801d2c40ad0 0000000000000008 0000000000000000
Call Trace:
 <IRQ> [  623.396277]  [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  623.396277]  [<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
 [<ffffffff810efdbc>] invoke_softirq kernel/softirq.c:368 [inline]
 [<ffffffff810efdbc>] irq_exit+0x11c/0x150 kernel/softirq.c:409
 [<ffffffff8281b771>] exiting_irq arch/x86/include/asm/apic.h:669 [inline]
 [<ffffffff8281b771>] smp_apic_timer_interrupt+0x81/0xb0 arch/x86/kernel/apic/apic.c:962
 [<ffffffff8281902d>] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [  623.791425]  [<ffffffff82816fbf>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
 <EOI> [  623.791425]  [<ffffffff82816fbf>] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline]
 <EOI> [  623.791425]  [<ffffffff82816fbf>] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff81ba9efd>] debug_object_free+0x22d/0x390 lib/debugobjects.c:586
 [<ffffffff8126ce4c>] destroy_hrtimer_on_stack kernel/time/hrtimer.c:424 [inline]
 [<ffffffff8126ce4c>] hrtimer_nanosleep+0x38c/0x550 kernel/time/hrtimer.c:1589
 [<ffffffff8126d0dc>] SYSC_nanosleep kernel/time/hrtimer.c:1604 [inline]
 [<ffffffff8126d0dc>] SyS_nanosleep+0xcc/0x120 kernel/time/hrtimer.c:1593
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Allocated by task 27061:
 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 25798:
 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
 kfree_const+0x39/0x50 mm/util.c:35
 kernfs_put+0x14f/0x580 fs/kernfs/dir.c:517
 __kernfs_remove+0x34e/0x820 fs/kernfs/dir.c:1242
 kernfs_remove_by_name_ns+0x54/0xb0 fs/kernfs/dir.c:1414
 sysfs_delete_link+0xe5/0x150 fs/sysfs/symlink.c:134
 device_remove_class_symlinks+0x140/0x1c0 drivers/base/core.c:936
 device_del+0x1e1/0x8e0 drivers/base/core.c:1275
 netdev_unregister_kobject+0xe6/0x110 net/core/net-sysfs.c:1534
 rollback_registered_many+0x691/0xb50 net/core/dev.c:6883
 rollback_registered+0xee/0x1b0 net/core/dev.c:6901
 unregister_netdevice_queue+0x1aa/0x230 net/core/dev.c:7888
 unregister_netdevice include/linux/netdevice.h:2465 [inline]
 __tun_detach+0x821/0xa00 drivers/net/tun.c:575
 tun_detach drivers/net/tun.c:585 [inline]
 tun_chr_close+0x44/0x60 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
 get_signal+0x1042/0x1460 kernel/signal.c:2151
 do_signal+0x95/0x1b00 arch/x86/kernel/signal.c:807
 exit_to_usermode_loop+0x10e/0x150 arch/x86/entry/common.c:158
 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 ffff8801d2c40ac8
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes to the right of
 8-byte region [ffff8801d2c40ac8, ffff8801d2c40ad0)
The buggy address belongs to the page:
page:ffffea00074b1000 count:1 mapcount:0 mapping:          (null) index:0xffff8801d2c40558
flags: 0x4000000000000080(slab)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d2c40980: fc fc fb fc fc fb fc fc fb fc fc fb fc fc fb fc
 ffff8801d2c40a00: fc fb fc fc fb fc fc fb fc fc fb fc fc fb fc fc
>ffff8801d2c40a80: fb fc fc fb fc fc fb fc fc 00 fc fc fb fc fc fb
                                                 ^
 ffff8801d2c40b00: fc fc fb fc fc fb fc fc fb fc fc fb fc fc fb fc
 ffff8801d2c40b80: fc fb fc fc fb fc fc fb fc fc fb fc fc fb fc fc
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