==================================================================
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 ffff8881d48571c8 by task syz.2.2396/6708

CPU: 1 PID: 6708 Comm: syz.2.2396 Not tainted 5.4.276-syzkaller-00020-g4275fce9fe94 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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/0x460 arch/x86/kernel/apic/apic.c:1149
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:memset+0x1/0x40 mm/kasan/common.c:105
Code: 7e ff 88 e8 09 00 00 c3 90 89 f6 48 8b 0c 24 31 d2 e9 93 22 00 00 0f 1f 00 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 80 22 00 00 55 <41> 56 53 48 89 d3 41 89 f6 48 89 fd 48 8b 4c 24 18 48 89 d6 ba 01
RSP: 0018:ffff8881d002ec70 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff8881d002efb5 RBX: ffff8881d002efb8 RCX: 1ffff1103a005df0
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff8881d002efd0
RBP: ffff8881d002ef70 R08: ffffffff8153b152 R09: ffffed103edeb135
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff094d64c
R13: ffffffff84a6b260 R14: ffff8881d002ef80 R15: dffffc0000000000
 unwind_next_frame+0x1036/0x1ea0 arch/x86/kernel/unwind_orc.c:534
 arch_stack_walk+0x111/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123
 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
 skb_clone+0x1c0/0x360 net/core/skbuff.c:1467
 ____bpf_clone_redirect net/core/filter.c:2136 [inline]
 bpf_clone_redirect+0xa2/0x350 net/core/filter.c:2123
 bpf_prog_4f53cad0028928b0+0xdd9/0x1000
 bpf_call_func include/linux/filter.h:627 [inline]
 bpf_test_run+0x2ae/0x6c0 net/bpf/test_run.c:44
 bpf_prog_test_run_skb+0x73c/0xf00 net/bpf/test_run.c:311
 bpf_prog_test_run kernel/bpf/syscall.c:2124 [inline]
 __do_sys_bpf kernel/bpf/syscall.c:2909 [inline]
 __se_sys_bpf+0x2e37/0xbcb0 kernel/bpf/syscall.c:2849
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f3e09cd3b99
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:00007f3e08f55048 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f3e09e61fa0 RCX: 00007f3e09cd3b99
RDX: 0000000000000050 RSI: 0000000020000080 RDI: 000000000000000a
RBP: 00007f3e09d5477e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f3e09e61fa0 R15: 00007ffe6ae2b828

The buggy address belongs to the page:
page:ffffea00075215c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 ffffea00077e2c08 ffffea0007521588 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+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]
 pcpu_alloc_pages mm/percpu-vm.c:94 [inline]
 pcpu_populate_chunk+0x1bb/0xd00 mm/percpu-vm.c:284
 pcpu_alloc+0x79e/0x1050 mm/percpu.c:1714
 prealloc_init+0x238/0x800 kernel/bpf/hashtab.c:154
 htab_map_alloc+0x638/0x930 kernel/bpf/hashtab.c:382
 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:2873 [inline]
 __se_sys_bpf+0x3291/0xbcb0 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:
 ffff8881d4857080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d4857100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881d4857180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881d4857200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d4857280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1da27c067 P4D 1da27c067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 6240 Comm: kworker/1:9 Tainted: G    B             5.4.276-syzkaller-00020-g4275fce9fe94 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202
RAX: ffffffff8154d48a RBX: 0000000000000101 RCX: ffff8881d9a6ee40
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881d48571c0
RBP: ffff8881f6f09ec8 R08: ffffffff8154d0ce R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffd0c0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d48571c0
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001ed86c000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 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/0x460 arch/x86/kernel/apic/apic.c:1149
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:preempt_count_sub+0x2e/0x160 kernel/sched/core.c:4040
Code: fb 48 c7 c0 c0 99 e9 86 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 0f b6 04 30 84 c0 0f 85 c0 00 00 00 83 3d 72 b9 a4 05 00 <75> 22 65 8b 05 35 ad bd 7e 89 c1 81 e1 ff ff ff 7f 39 d9 7c 23 81
RSP: 0018:ffff8881e4537ce8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff86e99903
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: ffff8881dc20c118 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000000000000
R13: dffffc0000000000 R14: dffffc0000000000 R15: ffffffff86178360
 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock+0x49/0x60 kernel/locking/spinlock.c:183
 spin_unlock include/linux/spinlock.h:378 [inline]
 wg_ratelimiter_gc_entries+0x3a7/0x440 drivers/net/wireguard/ratelimiter.c:76
 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 ac8773e599678fa4 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202
RAX: ffffffff8154d48a RBX: 0000000000000101 RCX: ffff8881d9a6ee40
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881d48571c0
RBP: ffff8881f6f09ec8 R08: ffffffff8154d0ce R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffd0c0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d48571c0
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001ed86c000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	7e ff                	jle    0x1
   2:	88 e8                	mov    %ch,%al
   4:	09 00                	or     %eax,(%rax)
   6:	00 c3                	add    %al,%bl
   8:	90                   	nop
   9:	89 f6                	mov    %esi,%esi
   b:	48 8b 0c 24          	mov    (%rsp),%rcx
   f:	31 d2                	xor    %edx,%edx
  11:	e9 93 22 00 00       	jmp    0x22a9
  16:	0f 1f 00             	nopl   (%rax)
  19:	89 f6                	mov    %esi,%esi
  1b:	48 8b 0c 24          	mov    (%rsp),%rcx
  1f:	ba 01 00 00 00       	mov    $0x1,%edx
  24:	e9 80 22 00 00       	jmp    0x22a9
  29:	55                   	push   %rbp
* 2a:	41 56                	push   %r14 <-- trapping instruction
  2c:	53                   	push   %rbx
  2d:	48 89 d3             	mov    %rdx,%rbx
  30:	41 89 f6             	mov    %esi,%r14d
  33:	48 89 fd             	mov    %rdi,%rbp
  36:	48 8b 4c 24 18       	mov    0x18(%rsp),%rcx
  3b:	48 89 d6             	mov    %rdx,%rsi
  3e:	ba                   	.byte 0xba
  3f:	01                   	.byte 0x1