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BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:773 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: use-after-free in detach_if_pending kernel/time/timer.c:841 [inline]
BUG: KASAN: use-after-free in try_to_del_timer_sync+0x2ad/0x460 kernel/time/timer.c:1238
Write of size 8 at addr ffff8881c179f1c8 by task syz-executor.2/14867

CPU: 1 PID: 14867 Comm: syz-executor.2 Not tainted 5.4.190-syzkaller-00003-g569d38047a0f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18e/0x1d5 lib/dump_stack.c:118
 print_address_description+0x8c/0x630 mm/kasan/report.c:384
 __kasan_report+0xf6/0x130 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __hlist_del include/linux/list.h:773 [inline]
 detach_timer kernel/time/timer.c:824 [inline]
 detach_if_pending kernel/time/timer.c:841 [inline]
 try_to_del_timer_sync+0x2ad/0x460 kernel/time/timer.c:1238
 del_timer_sync+0x74/0xd0 kernel/time/timer.c:1379
 tun_flow_uninit drivers/net/tun.c:1387 [inline]
 tun_free_netdev+0x99/0x3b0 drivers/net/tun.c:2328
 netdev_run_todo+0xa3c/0xc80 net/core/dev.c:9445
 tun_detach drivers/net/tun.c:751 [inline]
 tun_chr_close+0xc0/0xd0 drivers/net/tun.c:3523
 __fput+0x261/0x680 fs/file_table.c:281
 task_work_run+0x186/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xbe1/0x2b40 kernel/exit.c:812
 do_group_exit+0x136/0x300 kernel/exit.c:910
 get_signal+0xd99/0x13f0 kernel/signal.c:2735
 do_signal+0x3b/0x540 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xdd/0x1d0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x17c/0x1d0 arch/x86/entry/common.c:194
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:344
RIP: 0033:0x7f6092eb2531
Code: 48 85 ff 74 3d 48 85 f6 74 38 48 83 ee 10 48 89 4e 08 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 7c 13 74 01 c3 31 ed 58 5f ff d0 48 89 c7 b8 3c 00 00 00
RSP: 002b:00007f6091fc42f0 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: 0000000000000000 RBX: 00007f6091fc4700 RCX: 00007f6092eb2531
RDX: 00007f6091fc49d0 RSI: 00007f6091fc42f0 RDI: 00000000003d0f00
RBP: 00007fffa000b840 R08: 00007f6091fc4700 R09: 00007f6091fc4700
R10: 00007f6091fc49d0 R11: 0000000000000206 R12: 00007fffa000b6ae
R13: 00007fffa000b6af R14: 00007f6091fc4300 R15: 0000000000022000

The buggy address belongs to the page:
page:ffffea000705e7c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 ffffea0007baae08 ffffea000705e788 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 0, migratetype Unmovable, gfp_mask 0x102cc2(GFP_HIGHUSER|__GFP_NOWARN)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x194/0x380 mm/page_alloc.c:2171
 get_page_from_freelist+0x524/0x560 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x2ab/0x6f0 mm/page_alloc.c:4857
 __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]
 pcpu_alloc_pages mm/percpu-vm.c:94 [inline]
 pcpu_populate_chunk+0x121/0xca0 mm/percpu-vm.c:284
 pcpu_alloc+0x7dc/0x1060 mm/percpu.c:1714
 prealloc_init kernel/bpf/hashtab.c:154 [inline]
 htab_map_alloc+0x88c/0x11f0 kernel/bpf/hashtab.c:378
 find_and_alloc_map kernel/bpf/syscall.c:122 [inline]
 map_create kernel/bpf/syscall.c:573 [inline]
 __do_sys_bpf kernel/bpf/syscall.c:2871 [inline]
 __se_sys_bpf+0x2fe1/0xb990 kernel/bpf/syscall.c:2847
 do_syscall_64+0xcb/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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_pcp_prepare+0x1a4/0x290 mm/page_alloc.c:1233
 free_unref_page_prepare mm/page_alloc.c:3085 [inline]
 free_unref_page mm/page_alloc.c:3134 [inline]
 free_the_page mm/page_alloc.c:4917 [inline]
 __free_pages+0x52/0x1e0 mm/page_alloc.c:4925
 pcpu_free_pages mm/percpu-vm.c:64 [inline]
 pcpu_depopulate_chunk mm/percpu-vm.c:328 [inline]
 pcpu_balance_workfn+0x934/0x1270 mm/percpu.c:1865
 process_one_work+0x6ca/0xc40 kernel/workqueue.c:2287
 worker_thread+0xae0/0x1440 kernel/workqueue.c:2433
 kthread+0x2d8/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Memory state around the buggy address:
 ffff8881c179f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881c179f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881c179f180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881c179f200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881c179f280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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