==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
Write of size 8 at addr ffff8881de5a31c8 by task syz.4.879/3686

CPU: 1 PID: 3686 Comm: syz.4.879 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __dump_stack+0x1e/0x20 lib/dump_stack.c:77
 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118
 print_address_description+0x8d/0x4c0 mm/kasan/report.c:384
 __kasan_report+0xef/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:137
 hlist_add_head include/linux/list.h:814 [inline]
 enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
 __internal_add_timer kernel/time/timer.c:554 [inline]
 internal_add_timer+0x208/0x3e0 kernel/time/timer.c:604
 __mod_timer+0x5ab/0x1150 kernel/time/timer.c:1065
 mod_timer+0x1f/0x30 kernel/time/timer.c:1117
 can_stat_update+0xbab/0xc40 net/can/proc.c:186
 call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x81d/0xb60 kernel/time/timer.c:1817
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x236/0x660 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x197/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:539 [inline]
 smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:check_kcov_mode kernel/kcov.c:164 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x27/0x50 kernel/kcov.c:187
Code: 90 90 00 55 48 89 e5 48 8b 45 08 65 48 8b 0d 90 0e a3 7e 65 8b 15 95 0e a3 7e f7 c2 00 01 1f 00 74 02 5d c3 8b 91 00 0a 00 00 <83> fa 02 75 f3 48 8b 91 08 0a 00 00 48 8b 32 48 8d 7e 01 8b 89 04
RSP: 0018:ffff8881d426fb68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff816537b8 RBX: ffff8881d6b99000 RCX: ffff8881e7600fc0
RDX: 0000000000000002 RSI: 0000000000000159 RDI: 00000000000000b3
RBP: ffff8881d426fb68 R08: dffffc0000000000 R09: ffffed103a84df61
R10: ffffed103a84df61 R11: 1ffff1103a84df60 R12: 0000000000000159
R13: dffffc0000000000 R14: 00000000000000b3 R15: ffffffff85d67540
 perf_trace_init+0x128/0x200 kernel/trace/trace_event_perf.c:225
 perf_tp_event_init+0x8e/0x120 kernel/events/core.c:8905
 perf_try_init_event+0x14a/0x430 kernel/events/core.c:10358
 perf_init_event kernel/events/core.c:10409 [inline]
 perf_event_alloc+0xdb7/0x1920 kernel/events/core.c:10679
 __do_sys_perf_event_open kernel/events/core.c:11161 [inline]
 __se_sys_perf_event_open+0x6ae/0x1a90 kernel/events/core.c:11053
 __x64_sys_perf_event_open+0xbf/0xd0 kernel/events/core.c:11053
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7fcc0a78f969
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:00007fcc08df8038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fcc0a9b6fa0 RCX: 00007fcc0a78f969
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 00002000000010c0
RBP: 00007fcc0a811ab1 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcc0a9b6fa0 R15: 00007fff13bcf708

The buggy address belongs to the page:
page:ffffea00077968c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 dead000000000100 dead000000000122 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 0x106dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_ZERO)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x35e/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
 __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]
 __vmalloc_area_node mm/vmalloc.c:-1 [inline]
 __vmalloc_node_range+0x36a/0x6e0 mm/vmalloc.c:2499
 __vmalloc_node mm/vmalloc.c:2554 [inline]
 __vmalloc_node_flags_caller+0x7d/0x90 mm/vmalloc.c:2576
 bpf_map_area_alloc+0x83/0x90 kernel/bpf/syscall.c:155
 xsk_map_alloc+0x429/0x5d0 kernel/bpf/xskmap.c:119
 find_and_alloc_map kernel/bpf/syscall.c:122 [inline]
 map_create+0x2d8/0x980 kernel/bpf/syscall.c:573
 __do_sys_bpf kernel/bpf/syscall.c:2873 [inline]
 __se_sys_bpf+0x2dc/0x570 kernel/bpf/syscall.c:2849
 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849
 do_syscall_64+0xcf/0x170 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+0x2a9/0x3a0 mm/page_alloc.c:3085
 free_unref_page mm/page_alloc.c:3134 [inline]
 free_the_page mm/page_alloc.c:4954 [inline]
 __free_pages+0xaa/0x110 mm/page_alloc.c:4962
 __vunmap+0x76a/0x8a0 mm/vmalloc.c:2260
 __vfree mm/vmalloc.c:2308 [inline]
 vfree+0x61/0x90 mm/vmalloc.c:2338
 kvfree+0x3d/0x50 mm/util.c:623
 bpf_map_area_free+0x15/0x20 kernel/bpf/syscall.c:162
 xsk_map_free+0x72/0x80 kernel/bpf/xskmap.c:142
 bpf_map_free_deferred+0xaf/0x110 kernel/bpf/syscall.c:311
 process_one_work+0x73b/0xcc0 kernel/workqueue.c:2290
 worker_thread+0xa5c/0x13b0 kernel/workqueue.c:2436
 kthread+0x31e/0x3a0 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354

Memory state around the buggy address:
 ffff8881de5a3080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881de5a3100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881de5a3180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881de5a3200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881de5a3280: 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 0 P4D 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G    B             5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f5dc4ec0
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881de5a31c0
RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffb3d8
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881de5a31c0
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001ddf35000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x81d/0xb60 kernel/time/timer.c:1817
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x236/0x660 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x197/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:539 [inline]
 smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:default_idle+0x23/0x40 arch/x86/kernel/process.c:578
Code: 90 90 00 00 90 90 00 55 48 89 e5 e8 87 b2 f5 fd bf 01 00 00 00 89 c6 e8 bb 1c fc fc 0f 1f 44 00 00 0f 00 2d cf c2 59 00 fb f4 <e8> 68 b2 f5 fd bf ff ff ff ff 89 c6 e8 9c 1c fc fc 5d c3 66 2e 0f
RSP: 0018:ffff8881f5df7d80 EFLAGS: 000002c6 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: ffff8881f5dc4ec0 RCX: ffff8881f5dc4ec0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff8881f5df7d80 R08: dffffc0000000000 R09: ffffed103ebb89d9
R10: ffffed103ebb89d9 R11: 1ffff1103ebb89d8 R12: 0000000000000001
R13: 1ffff1103ebb89d8 R14: 0000000000000000 R15: ffffffff862bb528
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:568
 default_idle_call kernel/sched/idle.c:94 [inline]
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x21d/0x550 kernel/sched/idle.c:264
 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:356
 start_secondary+0x366/0x420 arch/x86/kernel/smpboot.c:277
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
Modules linked in:
CR2: 0000000000000000
---[ end trace b955f8f6af67cc15 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f5dc4ec0
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881de5a31c0
RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffb3d8
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881de5a31c0
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001ddf35000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	00 55 48             	add    %dl,0x48(%rbp)
   5:	89 e5                	mov    %esp,%ebp
   7:	48 8b 45 08          	mov    0x8(%rbp),%rax
   b:	65 48 8b 0d 90 0e a3 	mov    %gs:0x7ea30e90(%rip),%rcx        # 0x7ea30ea3
  12:	7e
  13:	65 8b 15 95 0e a3 7e 	mov    %gs:0x7ea30e95(%rip),%edx        # 0x7ea30eaf
  1a:	f7 c2 00 01 1f 00    	test   $0x1f0100,%edx
  20:	74 02                	je     0x24
  22:	5d                   	pop    %rbp
  23:	c3                   	ret
  24:	8b 91 00 0a 00 00    	mov    0xa00(%rcx),%edx
* 2a:	83 fa 02             	cmp    $0x2,%edx <-- trapping instruction
  2d:	75 f3                	jne    0x22
  2f:	48 8b 91 08 0a 00 00 	mov    0xa08(%rcx),%rdx
  36:	48 8b 32             	mov    (%rdx),%rsi
  39:	48 8d 7e 01          	lea    0x1(%rsi),%rdi
  3d:	8b                   	.byte 0x8b
  3e:	89                   	.byte 0x89
  3f:	04                   	.byte 0x4