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BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:791 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: use-after-free in detach_if_pending+0x188/0x360 kernel/time/timer.c:841
Write of size 8 at addr ffff8881e0c3f1c8 by task syz-executor.4/5803

CPU: 0 PID: 5803 Comm: syz-executor.4 Not tainted 5.4.268-syzkaller-04873-g2d5d8240a7cb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x241 lib/dump_stack.c:118
 print_address_description+0x8c/0x600 mm/kasan/report.c:384
 __kasan_report+0xf3/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __hlist_del include/linux/list.h:791 [inline]
 detach_timer kernel/time/timer.c:824 [inline]
 detach_if_pending+0x188/0x360 kernel/time/timer.c:841
 try_to_del_timer_sync kernel/time/timer.c:1238 [inline]
 del_timer_sync+0x13c/0x230 kernel/time/timer.c:1379
 tun_flow_uninit+0x2c/0x280 drivers/net/tun.c:1451
 tun_free_netdev+0x77/0x190 drivers/net/tun.c:2401
 netdev_run_todo+0xb7f/0xdf0 net/core/dev.c:9458
 tun_detach drivers/net/tun.c:765 [inline]
 tun_chr_close+0xc1/0x130 drivers/net/tun.c:3557
 __fput+0x262/0x680 fs/file_table.c:281
 task_work_run+0x140/0x170 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xcaf/0x2bc0 kernel/exit.c:859
 do_group_exit+0x138/0x300 kernel/exit.c:982
 get_signal+0xdb1/0x1440 kernel/signal.c:2735
 do_signal+0xb0/0x11f0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xc0/0x1a0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

The buggy address belongs to the page:
page:ffffea0007830fc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 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 0x146dc0(GFP_USER|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP|__GFP_ZERO)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4891
 __alloc_pages include/linux/gfp.h:503 [inline]
 __alloc_pages_node include/linux/gfp.h:516 [inline]
 alloc_pages_node include/linux/gfp.h:530 [inline]
 kmalloc_order mm/slab_common.c:1342 [inline]
 kmalloc_order_trace+0x2a/0x100 mm/slab_common.c:1358
 __kmalloc_node include/linux/slab.h:422 [inline]
 kmalloc_node include/linux/slab.h:599 [inline]
 kvmalloc_node+0x7e/0xf0 mm/util.c:596
 kvmalloc include/linux/mm.h:761 [inline]
 kvzalloc include/linux/mm.h:769 [inline]
 alloc_netdev_mqs+0x85/0xc70 net/core/dev.c:9610
 tun_set_iff+0x51f/0xdc0 drivers/net/tun.c:2887
 __tun_chr_ioctl+0x8a9/0x1d00 drivers/net/tun.c:3181
 do_vfs_ioctl+0x742/0x1720 fs/ioctl.c:47
 ksys_ioctl fs/ioctl.c:742 [inline]
 __do_sys_ioctl fs/ioctl.c:749 [inline]
 __se_sys_ioctl fs/ioctl.c:747 [inline]
 __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4953 [inline]
 __free_pages+0x91/0x140 mm/page_alloc.c:4959
 device_release+0x6b/0x190 drivers/base/core.c:1776
 kobject_cleanup lib/kobject.c:716 [inline]
 kobject_release lib/kobject.c:747 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e6/0x2f0 lib/kobject.c:764
 netdev_run_todo+0xc44/0xdf0 net/core/dev.c:9469
 tun_detach drivers/net/tun.c:765 [inline]
 tun_chr_close+0xc1/0x130 drivers/net/tun.c:3557
 __fput+0x262/0x680 fs/file_table.c:281
 task_work_run+0x140/0x170 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x190/0x1a0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881e0c3f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881e0c3f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881e0c3f180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881e0c3f200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881e0c3f280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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