==================================================================
BUG: KASAN: use-after-free in netdev_need_ops_lock include/net/netdev_lock.h:33 [inline]
BUG: KASAN: use-after-free in netdev_unlock_ops include/net/netdev_lock.h:47 [inline]
BUG: KASAN: use-after-free in __linkwatch_run_queue+0x865/0x8a0 net/core/link_watch.c:245
Read of size 8 at addr ffff88804de5c008 by task kworker/u32:10/8123

CPU: 0 UID: 0 PID: 8123 Comm: kworker/u32:10 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595
 netdev_need_ops_lock include/net/netdev_lock.h:33 [inline]
 netdev_unlock_ops include/net/netdev_lock.h:47 [inline]
 __linkwatch_run_queue+0x865/0x8a0 net/core/link_watch.c:245
 linkwatch_event+0x8f/0xc0 net/core/link_watch.c:304
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88804bd63d40 pfn:0x4de5c
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea00013c1808 ffff88802b341240 0000000000000000
raw: ffff88804bd63d40 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x546dc0(GFP_USER|__GFP_ZERO|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP|__GFP_ACCOUNT), pid 1278, tgid 1274 (syz.1.5183), ts 2370558567935, free_ts 2372429211756
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884
 prep_new_page mm/page_alloc.c:1892 [inline]
 get_page_from_freelist+0xe3d/0x2e10 mm/page_alloc.c:3945
 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5240
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
 ___kmalloc_large_node+0x104/0x150 mm/slub.c:5598
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:5629
 __do_kmalloc_node mm/slub.c:5645 [inline]
 __kvmalloc_node_noprof+0x5de/0xac0 mm/slub.c:7140
 alloc_netdev_mqs+0xd7/0x14f0 net/core/dev.c:12012
 tun_set_iff drivers/net/tun.c:2778 [inline]
 __tun_chr_ioctl+0x1878/0x47c0 drivers/net/tun.c:3088
 __do_compat_sys_ioctl fs/ioctl.c:695 [inline]
 __se_compat_sys_ioctl fs/ioctl.c:638 [inline]
 __ia32_compat_sys_ioctl+0x2cf/0x360 fs/ioctl.c:638
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xde/0x660 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
page last free pid 1274 tgid 1274 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973
 device_release+0xa4/0x240 drivers/base/core.c:2565
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1f7/0x640 lib/kobject.c:737
 netdev_run_todo+0x817/0x12c0 net/core/dev.c:11713
 tun_detach drivers/net/tun.c:640 [inline]
 tun_chr_close+0xea/0x220 drivers/net/tun.c:3436
 __fput+0x3ff/0xb40 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 __do_fast_syscall_32+0x4b6/0x660 arch/x86/entry/syscall_32.c:310
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Memory state around the buggy address:
 ffff88804de5bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804de5bf80: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff88804de5c000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                      ^
 ffff88804de5c080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804de5c100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================