==================================================================
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 ffff8881e26031c8 by task syz.1.317/1568

CPU: 0 PID: 1568 Comm: syz.1.317 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:arch_atomic64_add_return arch/x86/include/asm/atomic64_64.h:160 [inline]
RIP: 0010:atomic64_add_return include/asm-generic/atomic-instrumented.h:882 [inline]
RIP: 0010:atomic_long_add_return_release include/asm-generic/atomic-long.h:70 [inline]
RIP: 0010:__up_read kernel/locking/rwsem.c:1471 [inline]
RIP: 0010:up_read+0x7b/0x1b0 kernel/locking/rwsem.c:1625
Code: 24 20 49 c1 ec 03 48 b8 f1 f1 f1 f1 00 00 f3 f3 4b 89 04 34 be 08 00 00 00 e8 01 3c 48 00 48 c7 c0 00 ff ff ff f0 48 0f c1 03 <48> 05 00 ff ff ff 48 25 03 ff ff ff 48 83 f8 02 74 34 48 c7 44 24
RSP: 0018:ffff8881cbf77c80 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000100 RBX: ffff8881df48e9f0 RCX: ffffffff814bcc9f
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8881df48e9f0
RBP: ffff8881cbf77d30 R08: dffffc0000000000 R09: ffffed103be91d3f
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff110397eef94
R13: 0000000000000010 R14: dffffc0000000000 R15: ffff8881e0713f00
 __do_sys_perf_event_open kernel/events/core.c:11468 [inline]
 __se_sys_perf_event_open+0x3352/0x37c0 kernel/events/core.c:11052
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f87bcff7169
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:00007f87bb661038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f87bd20ffa0 RCX: 00007f87bcff7169
RDX: ffefffffffffffff RSI: 0000000000000000 RDI: 0000400000000a00
RBP: 00007f87bd0782a0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f87bd20ffa0 R15: 00007fffba19f158

Allocated by task 355:
 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
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
 shmem_alloc_inode+0x16/0x30 mm/shmem.c:3719
 alloc_inode fs/inode.c:231 [inline]
 new_inode_pseudo+0x60/0x210 fs/inode.c:966
 new_inode+0x25/0x1d0 fs/inode.c:995
 shmem_get_inode+0x10b/0x620 mm/shmem.c:2252
 shmem_symlink+0x118/0x5f0 mm/shmem.c:3068
 vfs_symlink+0x36c/0x500 fs/namei.c:4276
 do_symlinkat+0x19b/0x400 fs/namei.c:4303
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 17:
 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]
 kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167
 rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292

The buggy address belongs to the object at ffff8881e2603090
 which belongs to the cache shmem_inode_cache of size 760
The buggy address is located 312 bytes inside of
 760-byte region [ffff8881e2603090, ffff8881e2603388)
The buggy address belongs to the page:
page:ffffea0007898000 refcount:1 mapcount:0 mapping:ffff8881f5cfec80 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cfec80
raw: 0000000000000000 0000000000120012 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, 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]
 kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
 shmem_alloc_inode+0x16/0x30 mm/shmem.c:3719
 alloc_inode fs/inode.c:231 [inline]
 new_inode_pseudo+0x60/0x210 fs/inode.c:966
 new_inode+0x25/0x1d0 fs/inode.c:995
 shmem_get_inode+0x10b/0x620 mm/shmem.c:2252
 shmem_mknod+0x54/0x1a0 mm/shmem.c:2844
 shmem_mkdir+0x26/0x50 mm/shmem.c:2895
 vfs_mkdir+0x4b9/0x690 fs/namei.c:3965
 do_mkdirat+0x1a6/0x2c0 fs/namei.c:3987
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
 tun_set_iff+0x870/0xdc0 drivers/net/tun.c:2924
 __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

Memory state around the buggy address:
 ffff8881e2603080: fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881e2603100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881e2603180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8881e2603200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881e2603280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1e00f1067 P4D 1e00f1067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 108 Comm: kworker/0:2 Tainted: G    B             5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: rcu_gp process_srcu
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010002
RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881ee845e80
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881e26031c0
RBP: ffff8881f6e09ec8 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffff9e60
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e26031c0
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001eb8ba000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1488 [inline]
 __run_timers+0x8a5/0xbe0 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:check_preemption_disabled+0x2c/0x320 lib/smp_processor_id.c:13
Code: 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 80 00 00 00 49 89 f7 49 89 fc 65 48 8b 04 25 28 00 00 00 48 89 44 24 60 <48> c7 44 24 20 b3 8a b5 41 48 c7 44 24 28 4a c5 58 85 48 c7 44 24
RSP: 0018:ffff8881ede27b20 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 8ae4c966978c2300 RBX: 0000001bd68f7534 RCX: ffff8881ee845e80
RDX: 0000000000000000 RSI: ffffffff84fa5560 RDI: ffffffff84fa5520
RBP: ffff8881ede27bd8 R08: ffffffff8231cd01 R09: ffffed103dbc4f81
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff84fa5520
R13: 1ffffffff0c989d1 R14: 0000000000002afa R15: ffffffff84fa5560
 delay_tsc+0x67/0xd0 arch/x86/lib/delay.c:79
 try_check_zero+0x2f2/0x360 kernel/rcu/srcutree.c:708
 srcu_advance_state kernel/rcu/srcutree.c:1146 [inline]
 process_srcu+0x1ab/0xc40 kernel/rcu/srcutree.c:1241
 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
Modules linked in:
CR2: 0000000000000000
---[ end trace 5f5fde41e6711f2c ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010002
RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881ee845e80
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881e26031c0
RBP: ffff8881f6e09ec8 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffff9e60
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e26031c0
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001eb8ba000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	24 20                	and    $0x20,%al
   2:	49 c1 ec 03          	shr    $0x3,%r12
   6:	48 b8 f1 f1 f1 f1 00 	movabs $0xf3f30000f1f1f1f1,%rax
   d:	00 f3 f3
  10:	4b 89 04 34          	mov    %rax,(%r12,%r14,1)
  14:	be 08 00 00 00       	mov    $0x8,%esi
  19:	e8 01 3c 48 00       	call   0x483c1f
  1e:	48 c7 c0 00 ff ff ff 	mov    $0xffffffffffffff00,%rax
  25:	f0 48 0f c1 03       	lock xadd %rax,(%rbx)
* 2a:	48 05 00 ff ff ff    	add    $0xffffffffffffff00,%rax <-- trapping instruction
  30:	48 25 03 ff ff ff    	and    $0xffffffffffffff03,%rax
  36:	48 83 f8 02          	cmp    $0x2,%rax
  3a:	74 34                	je     0x70
  3c:	48                   	rex.W
  3d:	c7                   	.byte 0xc7
  3e:	44                   	rex.R
  3f:	24                   	.byte 0x24