==================================================================
BUG: KASAN: slab-out-of-bounds in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: slab-out-of-bounds in enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
Write of size 8 at addr ffff8881e18471c8 by task syz.2.219/1259

CPU: 0 PID: 1259 Comm: syz.2.219 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x51/0x80 kernel/locking/spinlock.c:191
Code: 89 fe 48 c7 c7 b0 2d cb 85 e8 ab 7f 62 fd 4c 89 f7 48 83 3d 40 34 a0 01 00 74 34 e8 0d 38 1d fd 66 90 48 89 5d e8 ff 75 e8 9d <bf> 01 00 00 00 e8 e5 7a 16 fd 65 8b 05 fa 93 d7 7b 85 c0 74 09 48
RSP: 0018:ffff8881e167f2c0 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: 0000000000000a06 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000a06 RDI: ffff8881e26c9da8
RBP: ffff8881e167f2d8 R08: dffffc0000000000 R09: ffffed103b96d4c0
R10: ffffed103b96d4c0 R11: 1ffff1103b96d4bf R12: 0000000000000a06
R13: ffffea00072524c8 R14: ffff8881e26c9da0 R15: ffff8881e26c9da8
 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline]
 delete_from_page_cache+0xc9/0x100 mm/filemap.c:274
 truncate_inode_page+0x5d/0x70 mm/truncate.c:225
 shmem_undo_range+0x6ad/0x1860 mm/shmem.c:869
 shmem_truncate_range mm/shmem.c:997 [inline]
 shmem_evict_inode+0x204/0x9a0 mm/shmem.c:1097
 evict+0x465/0x880 fs/inode.c:610
 iput_final fs/inode.c:1652 [inline]
 iput+0x67d/0x810 fs/inode.c:1678
 dentry_unlink_inode+0x2ca/0x370 fs/dcache.c:378
 __dentry_kill+0x43e/0x640 fs/dcache.c:583
 dentry_kill+0xc0/0x2a0 fs/dcache.c:677
 dput+0x42/0x80 fs/dcache.c:864
 __fput+0x4ba/0x730 fs/file_table.c:294
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x146/0x170 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xa43/0x2660 kernel/exit.c:861
 do_group_exit+0x13e/0x300 kernel/exit.c:984
 get_signal+0xdee/0x13d0 kernel/signal.c:2738
 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
 ret_from_intr+0x1c/0x1c
RIP: 0033:0x0
Code: Bad RIP value.
RSP: 002b:0000200000000158 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f6b0779ffa0 RCX: 00007f6b07578969
RDX: 0000200000000180 RSI: 0000200000000150 RDI: 0000000000000080
RBP: 00007f6b075faab1 R08: 0000200000000200 R09: 0000200000000200
R10: 00002000000001c0 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6b0779ffa0 R15: 00007ffdb9c3c2f8

Allocated by task 1309:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529
 kasan_kmalloc+0xd/0x20 mm/kasan/common.c:543
 __kmalloc+0x12a/0x2f0 mm/slub.c:3913
 kmalloc_array include/linux/slab.h:618 [inline]
 realloc_stack_state kernel/bpf/verifier.c:595 [inline]
 realloc_func_state+0x305/0x5b0 kernel/bpf/verifier.c:611
 check_stack_write+0xda/0x1b10 kernel/bpf/verifier.c:1926
 check_mem_access+0x9b4/0x1c30 kernel/bpf/verifier.c:2920
 do_check+0x430c/0x8a60 kernel/bpf/verifier.c:8003
 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637
 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724
 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline]
 __se_sys_bpf+0x435/0x570 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

Freed by task 1309:
 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+0x1c3/0x280 mm/kasan/common.c:487
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494
 slab_free mm/slub.c:3080 [inline]
 kfree+0xbe/0x260 mm/slub.c:4071
 realloc_stack_state kernel/bpf/verifier.c:595 [inline]
 realloc_func_state+0x477/0x5b0 kernel/bpf/verifier.c:611
 check_stack_write+0xda/0x1b10 kernel/bpf/verifier.c:1926
 check_mem_access+0x9b4/0x1c30 kernel/bpf/verifier.c:2920
 do_check+0x430c/0x8a60 kernel/bpf/verifier.c:8003
 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637
 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724
 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline]
 __se_sys_bpf+0x435/0x570 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

The buggy address belongs to the object at ffff8881e1844000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4552 bytes to the right of
 8192-byte region [ffff8881e1844000, ffff8881e1846000)
The buggy address belongs to the page:
page:ffffea0007861000 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+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_slab_page+0x3c/0x3b0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x93/0x420 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x29e/0x420 mm/slub.c:2667
 __slab_alloc+0x63/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 __kmalloc+0x176/0x2f0 mm/slub.c:3909
 kmalloc_array include/linux/slab.h:618 [inline]
 realloc_stack_state kernel/bpf/verifier.c:595 [inline]
 realloc_func_state+0x305/0x5b0 kernel/bpf/verifier.c:611
 check_stack_write+0xda/0x1b10 kernel/bpf/verifier.c:1926
 check_mem_access+0x9b4/0x1c30 kernel/bpf/verifier.c:2920
 do_check+0x430c/0x8a60 kernel/bpf/verifier.c:8003
 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637
 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724
 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline]
 __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849
 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849
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
 pcpu_free_pages mm/percpu-vm.c:64 [inline]
 pcpu_depopulate_chunk mm/percpu-vm.c:328 [inline]
 pcpu_balance_workfn+0x8c7/0x14b0 mm/percpu.c:1865
 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:
 ffff8881e1847080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881e1847100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881e1847180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                              ^
 ffff8881e1847200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881e1847280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
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: 0 PID: 1259 Comm: syz.2.219 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:ffff8881f6e09cf0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881e1ab8000
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881e18471c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9a78
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e18471c0
FS:  00007f6b05be16c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001ecdfc000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 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:__sanitizer_cov_trace_pc+0x1f/0x50 kernel/kcov.c:197
Code: 5d c3 00 00 90 90 00 00 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
RSP: 0018:ffff8881e167f2a0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81804d87 RBX: ffffea000741a680 RCX: ffff8881e1ab8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8881e167f2a0 R08: dffffc0000000000 R09: fffff94000e834d1
R10: fffff94000e834d1 R11: 1ffffd4000e834d0 R12: dffffc0000000000
R13: 1ffffd4000e834d1 R14: 0000000000000000 R15: 0000000000080000
 page_mapping+0x1d7/0x2d0 mm/util.c:708
 delete_from_page_cache+0x25/0x100 mm/filemap.c:268
 truncate_inode_page+0x5d/0x70 mm/truncate.c:225
 shmem_undo_range+0x6ad/0x1860 mm/shmem.c:869
 shmem_truncate_range mm/shmem.c:997 [inline]
 shmem_evict_inode+0x204/0x9a0 mm/shmem.c:1097
 evict+0x465/0x880 fs/inode.c:610
 iput_final fs/inode.c:1652 [inline]
 iput+0x67d/0x810 fs/inode.c:1678
 dentry_unlink_inode+0x2ca/0x370 fs/dcache.c:378
 __dentry_kill+0x43e/0x640 fs/dcache.c:583
 dentry_kill+0xc0/0x2a0 fs/dcache.c:677
 dput+0x42/0x80 fs/dcache.c:864
 __fput+0x4ba/0x730 fs/file_table.c:294
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x146/0x170 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xa43/0x2660 kernel/exit.c:861
 do_group_exit+0x13e/0x300 kernel/exit.c:984
 get_signal+0xdee/0x13d0 kernel/signal.c:2738
 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
 ret_from_intr+0x1c/0x1c
RIP: 0033:0x0
Code: Bad RIP value.
RSP: 002b:0000200000000158 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f6b0779ffa0 RCX: 00007f6b07578969
RDX: 0000200000000180 RSI: 0000200000000150 RDI: 0000000000000080
RBP: 00007f6b075faab1 R08: 0000200000000200 R09: 0000200000000200
R10: 00002000000001c0 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6b0779ffa0 R15: 00007ffdb9c3c2f8
Modules linked in:
CR2: 0000000000000000
---[ end trace 39d02ff924ba3d39 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881e1ab8000
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881e18471c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9a78
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e18471c0
FS:  00007f6b05be16c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001ecdfc000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	89 fe                	mov    %edi,%esi
   2:	48 c7 c7 b0 2d cb 85 	mov    $0xffffffff85cb2db0,%rdi
   9:	e8 ab 7f 62 fd       	call   0xfd627fb9
   e:	4c 89 f7             	mov    %r14,%rdi
  11:	48 83 3d 40 34 a0 01 	cmpq   $0x0,0x1a03440(%rip)        # 0x1a03459
  18:	00
  19:	74 34                	je     0x4f
  1b:	e8 0d 38 1d fd       	call   0xfd1d382d
  20:	66 90                	xchg   %ax,%ax
  22:	48 89 5d e8          	mov    %rbx,-0x18(%rbp)
  26:	ff 75 e8             	push   -0x18(%rbp)
  29:	9d                   	popf
* 2a:	bf 01 00 00 00       	mov    $0x1,%edi <-- trapping instruction
  2f:	e8 e5 7a 16 fd       	call   0xfd167b19
  34:	65 8b 05 fa 93 d7 7b 	mov    %gs:0x7bd793fa(%rip),%eax        # 0x7bd79435
  3b:	85 c0                	test   %eax,%eax
  3d:	74 09                	je     0x48
  3f:	48                   	rex.W