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BUG: KASAN: slab-out-of-bounds in __hlist_del include/linux/list.h:791 [inline]
BUG: KASAN: slab-out-of-bounds in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: slab-out-of-bounds in detach_if_pending+0x188/0x360 kernel/time/timer.c:841
Write of size 8 at addr ffff8881d95531c8 by task syz.6.699/3123

CPU: 1 PID: 3123 Comm: syz.6.699 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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:1267 [inline]
 del_timer_sync+0x13c/0x230 kernel/time/timer.c:1410
 tun_flow_uninit+0x2c/0x280 drivers/net/tun.c:1452
 tun_free_netdev+0x77/0x190 drivers/net/tun.c:2404
 netdev_run_todo+0xb7f/0xdf0 net/core/dev.c:9477
 tun_detach drivers/net/tun.c:766 [inline]
 tun_chr_close+0xc1/0x130 drivers/net/tun.c:3563
 __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
RIP: 0033:0x7fe3ead5adca
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 43 91 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 a3 91 02 00 8b 44 24
RSP: 002b:00007fffb2b92c50 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000009 RCX: 00007fe3ead5adca
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007fe3eaf76ba0 R08: 000000000000019c R09: 00000016b2b92f5f
R10: 00007fe3eaf76ac0 R11: 0000000000000293 R12: 00000000000171e9
R13: 00007fe3eaf75160 R14: ffffffffffffffff R15: 00007fffb2b92d80

Allocated by task 3103:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
 kmalloc_array include/linux/slab.h:618 [inline]
 realloc_stack_state kernel/bpf/verifier.c:595 [inline]
 realloc_func_state+0x2ee/0x5a0 kernel/bpf/verifier.c:611
 copy_func_state kernel/bpf/verifier.c:704 [inline]
 copy_verifier_state+0x655/0xbf0 kernel/bpf/verifier.c:751
 push_stack+0x153/0x470 kernel/bpf/verifier.c:819
 check_cond_jmp_op+0x719/0x17d0 kernel/bpf/verifier.c:6192
 do_check+0x4ba1/0x9820 kernel/bpf/verifier.c:8109
 bpf_check+0x2183/0xb3e0 kernel/bpf/verifier.c:9637
 bpf_prog_load kernel/bpf/syscall.c:1724 [inline]
 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline]
 __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 3103:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1494 [inline]
 slab_free mm/slub.c:3080 [inline]
 kfree+0x123/0x370 mm/slub.c:4071
 free_func_state kernel/bpf/verifier.c:671 [inline]
 free_verifier_state+0xd6/0x230 kernel/bpf/verifier.c:688
 pop_stack kernel/bpf/verifier.c:795 [inline]
 bpf_check+0x24de/0xb3e0 kernel/bpf/verifier.c:9647
 bpf_prog_load kernel/bpf/syscall.c:1724 [inline]
 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline]
 __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

The buggy address belongs to the object at ffff8881d9550000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4552 bytes to the right of
 8192-byte region [ffff8881d9550000, ffff8881d9552000)
The buggy address belongs to the page:
page:ffffea0007655400 refcount:1 mapcount:0 mapping:ffff8881f5c0c500 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c0c500
raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL)
 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:4893
 alloc_slab_page+0x39/0x3c0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x97/0x440 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x2fe/0x490 mm/slub.c:2667
 __slab_alloc+0x62/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 __kmalloc+0x19b/0x2e0 mm/slub.c:3909
 kmalloc_array include/linux/slab.h:618 [inline]
 realloc_stack_state kernel/bpf/verifier.c:595 [inline]
 realloc_func_state+0x2ee/0x5a0 kernel/bpf/verifier.c:611
 copy_func_state kernel/bpf/verifier.c:704 [inline]
 copy_verifier_state+0x655/0xbf0 kernel/bpf/verifier.c:751
 is_state_visited kernel/bpf/verifier.c:7702 [inline]
 do_check+0x3286/0x9820 kernel/bpf/verifier.c:7837
 bpf_check+0x2183/0xb3e0 kernel/bpf/verifier.c:9637
 bpf_prog_load kernel/bpf/syscall.c:1724 [inline]
 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline]
 __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849
 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_pcp_prepare mm/page_alloc.c:1233 [inline]
 free_unref_page_prepare+0x297/0x380 mm/page_alloc.c:3085
 free_unref_page mm/page_alloc.c:3134 [inline]
 free_the_page mm/page_alloc.c:4953 [inline]
 __free_pages+0xaf/0x140 mm/page_alloc.c:4961
 pcpu_free_pages mm/percpu-vm.c:64 [inline]
 pcpu_depopulate_chunk mm/percpu-vm.c:328 [inline]
 pcpu_balance_workfn+0x940/0x1450 mm/percpu.c:1865
 process_one_work+0x765/0xd20 kernel/workqueue.c:2290
 worker_thread+0xaef/0x1470 kernel/workqueue.c:2436
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354

Memory state around the buggy address:
 ffff8881d9553080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881d9553100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881d9553180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                              ^
 ffff8881d9553200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881d9553280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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