==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0xb7/0x300 kernel/time/timer.c:541
Write of size 8 at addr ffff8881d487f1c8 by task syz.6.757/3287

CPU: 0 PID: 3287 Comm: syz.6.757 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __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_add_head include/linux/list.h:814 [inline]
 enqueue_timer+0xb7/0x300 kernel/time/timer.c:541
 __internal_add_timer kernel/time/timer.c:554 [inline]
 internal_add_timer+0x240/0x430 kernel/time/timer.c:604
 __mod_timer+0x6f1/0x13e0 kernel/time/timer.c:1065
 call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x879/0xbe0 kernel/time/timer.c:1817
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x195/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:539 [inline]
 smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x50 kernel/kcov.c:192
Code: 0d 74 42 9e 7e 65 8b 15 79 42 9e 7e f7 c2 00 01 1f 00 74 01 c3 8b 91 00 0a 00 00 83 fa 02 75 f4 48 8b 91 08 0a 00 00 48 8b 32 <48> 8d 7e 01 8b 89 04 0a 00 00 48 39 cf 73 db 48 89 44 f2 08 48 89
RSP: 0018:ffff8881dcff70b8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff83dbc244 RBX: 0000000000000044 RCX: ffff8881ea806e40
RDX: ffffc90002146000 RSI: 000000000006de90 RDI: 0000000000000000
RBP: ffff8881dcff7230 R08: ffffffff83dbc12c R09: ffffed103ad3b34e
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000187
R13: dffffc0000000000 R14: ffff8881dcff7188 R15: 0000000000000000
 __fib6_clean_all net/ipv6/ip6_fib.c:2152 [inline]
 fib6_flush_trees+0x2b4/0x330 net/ipv6/ip6_fib.c:2179
 rt_genid_bump_ipv6 include/net/net_namespace.h:454 [inline]
 add_addr+0x247/0x470 net/ipv6/addrconf.c:3144
 sit_add_v4_addrs net/ipv6/addrconf.c:3201 [inline]
 addrconf_sit_config+0x8b7/0x1410 net/ipv6/addrconf.c:3452
 addrconf_notify+0x9a5/0xe50 net/ipv6/addrconf.c:3647
 notifier_call_chain kernel/notifier.c:98 [inline]
 __raw_notifier_call_chain kernel/notifier.c:399 [inline]
 raw_notifier_call_chain+0x95/0x110 kernel/notifier.c:406
 __dev_notify_flags+0x26e/0x510 net/core/dev.c:1670
 dev_change_flags+0xe7/0x190 net/core/dev.c:8034
 dev_ifsioc+0x104/0xa60 net/core/dev_ioctl.c:226
 dev_ioctl+0x505/0xb40 net/core/dev_ioctl.c:483
 sock_do_ioctl+0x295/0x3a0 net/socket.c:1081
 sock_ioctl+0x4a4/0x760 net/socket.c:1198
 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
RIP: 0033:0x7eff96ee2169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007eff9554c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007eff970fafa0 RCX: 00007eff96ee2169
RDX: 0000400000000040 RSI: 0000000000008914 RDI: 000000000000000d
RBP: 00007eff96f632a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007eff970fafa0 R15: 00007ffe4e484948

The buggy address belongs to the page:
page:ffffea0007521fc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 0000000000000000 ffffea0007521f88 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:4893
 __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:9629
 tun_set_iff+0x51f/0xdc0 drivers/net/tun.c:2893
 __tun_chr_ioctl+0x8a9/0x1d00 drivers/net/tun.c:3187
 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:4955 [inline]
 __free_pages+0x91/0x140 mm/page_alloc.c:4961
 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:9488
 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

Memory state around the buggy address:
 ffff8881d487f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d487f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881d487f180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881d487f200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d487f280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 23 Comm: kauditd Tainted: G    B             5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__hlist_del include/linux/list.h:791 [inline]
RIP: 0010:detach_timer kernel/time/timer.c:824 [inline]
RIP: 0010:expire_timers kernel/time/timer.c:1482 [inline]
RIP: 0010:__run_timers+0x7b0/0xbe0 kernel/time/timer.c:1817
Code: 89 e7 e8 63 51 3f 00 4d 89 2c 24 4d 85 ed 74 2e e8 a5 66 0f 00 49 83 c5 08 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 32 51 3f 00 4d 89 65 00 eb 05 e8 77
RSP: 0018:ffff8881f6e09d60 EFLAGS: 00010802
RAX: 1bd5a00000000025 RBX: 1ffff1103a90fe39 RCX: dffffc0000000000
RDX: 0000000080000102 RSI: 0000000000000008 RDI: ffff8881d487f1c8
RBP: ffff8881f6e09ec8 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff8881f6e09e20
R13: dead00000000012a R14: 1ffff1103a90fe38 R15: ffff8881d487f1c8
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001ece8d000 CR4: 00000000003406b0
DR0: 0000400000000300 DR1: 0000400000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x195/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:539 [inline]
 smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline]
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline]
RIP: 0010:console_unlock+0xa62/0xfa0 kernel/printk/printk.c:2527
Code: 03 84 db 4c 8d ac 24 00 01 00 00 0f 85 13 05 00 00 e8 52 e3 16 00 e8 5d 5f 00 00 48 8b 44 24 20 48 89 44 24 70 ff 74 24 70 9d <e9> 99 f7 ff ff e8 34 e3 16 00 48 c7 05 e9 15 a0 05 00 00 00 00 e9
RSP: 0018:ffff8881f23df940 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000246 RBX: 0000000000000000 RCX: ffff8881f5cdee40
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: ffff8881f23dfaf0 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8881f23dfa40 R14: 0000000000000000 R15: ffffffff812ee850
 vprintk_emit+0x1e0/0x3f0 kernel/printk/printk.c:2032
 printk+0xd1/0x111 kernel/printk/printk.c:2092
 kauditd_printk_skb kernel/audit.c:543 [inline]
 kauditd_hold_skb+0x1b3/0x200 kernel/audit.c:578
 kauditd_send_queue+0x297/0x2f0 kernel/audit.c:763
 kauditd_thread+0x4ff/0x860 kernel/audit.c:887
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Modules linked in:
---[ end trace 9b4dda4e2445d30e ]---
RIP: 0010:__hlist_del include/linux/list.h:791 [inline]
RIP: 0010:detach_timer kernel/time/timer.c:824 [inline]
RIP: 0010:expire_timers kernel/time/timer.c:1482 [inline]
RIP: 0010:__run_timers+0x7b0/0xbe0 kernel/time/timer.c:1817
Code: 89 e7 e8 63 51 3f 00 4d 89 2c 24 4d 85 ed 74 2e e8 a5 66 0f 00 49 83 c5 08 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 32 51 3f 00 4d 89 65 00 eb 05 e8 77
RSP: 0018:ffff8881f6e09d60 EFLAGS: 00010802
RAX: 1bd5a00000000025 RBX: 1ffff1103a90fe39 RCX: dffffc0000000000
RDX: 0000000080000102 RSI: 0000000000000008 RDI: ffff8881d487f1c8
RBP: ffff8881f6e09ec8 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff8881f6e09e20
R13: dead00000000012a R14: 1ffff1103a90fe38 R15: ffff8881d487f1c8
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001ece8d000 CR4: 00000000003406b0
DR0: 0000400000000300 DR1: 0000400000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	0d 74 42 9e 7e       	or     $0x7e9e4274,%eax
   5:	65 8b 15 79 42 9e 7e 	mov    %gs:0x7e9e4279(%rip),%edx        # 0x7e9e4285
   c:	f7 c2 00 01 1f 00    	test   $0x1f0100,%edx
  12:	74 01                	je     0x15
  14:	c3                   	ret
  15:	8b 91 00 0a 00 00    	mov    0xa00(%rcx),%edx
  1b:	83 fa 02             	cmp    $0x2,%edx
  1e:	75 f4                	jne    0x14
  20:	48 8b 91 08 0a 00 00 	mov    0xa08(%rcx),%rdx
  27:	48 8b 32             	mov    (%rdx),%rsi
* 2a:	48 8d 7e 01          	lea    0x1(%rsi),%rdi <-- trapping instruction
  2e:	8b 89 04 0a 00 00    	mov    0xa04(%rcx),%ecx
  34:	48 39 cf             	cmp    %rcx,%rdi
  37:	73 db                	jae    0x14
  39:	48 89 44 f2 08       	mov    %rax,0x8(%rdx,%rsi,8)
  3e:	48                   	rex.W
  3f:	89                   	.byte 0x89