__kernel_write_iter+0x425/0x910 fs/read_write.c:619
 __kernel_write fs/read_write.c:639 [inline]
 kernel_write+0x1ca/0x2e0 fs/read_write.c:660
 process_sysctl_arg+0x39c/0x5f0 fs/proc/proc_sysctl.c:1687
 parse_one kernel/params.c:153 [inline]
 parse_args+0x310/0xa70 kernel/params.c:186
 do_sysctl_args+0xd0/0x150 fs/proc/proc_sysctl.c:1719
 kernel_init+0x84/0x1d0 init/main.c:1492
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page_owner free stack trace missing
------------[ cut here ]------------
kernel BUG at mm/filemap.c:154!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 12837 Comm: syz.3.1637 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:filemap_unaccount_folio+0x715/0x790 mm/filemap.c:154
Code: a3 c9 ff 48 89 df 48 c7 c6 e0 3b 94 8b e8 f3 f0 31 ff 90 0f 0b e8 bb a3 c9 ff 48 89 df 48 c7 c6 c0 3a 94 8b e8 dc f0 31 ff 90 <0f> 0b e8 a4 a3 c9 ff 48 89 df 48 c7 c6 e0 3b 94 8b e8 c5 f0 31 ff
RSP: 0018:ffffc9000ac6ede0 EFLAGS: 00010046
RAX: 4c7b66f2d5fa4c00 RBX: ffffea0008eb0000 RCX: 4c7b66f2d5fa4c00
RDX: 0000000000000005 RSI: ffffffff8dba8965 RDI: ffff888027329e00
RBP: 0000000000000001 R08: ffff8880b8724253 R09: 1ffff110170e484a
R10: dffffc0000000000 R11: ffffed10170e484b R12: 0000000000000040
R13: 1ffffd40011d6000 R14: 1ffffd40011d6001 R15: ffffea0008eb0008
FS:  0000000000000000(0000) GS:ffff888125d15000(0063) knlGS:00000000f47fbb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000800bd01c CR3: 000000007870a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __filemap_remove_folio+0xc3/0x500 mm/filemap.c:223
 filemap_remove_folio+0xe6/0x1f0 mm/filemap.c:253
 hugetlb_delete_from_page_cache fs/hugetlbfs/inode.c:331 [inline]
 remove_inode_single_folio fs/hugetlbfs/inode.c:536 [inline]
 remove_inode_hugepages+0x594/0x1100 fs/hugetlbfs/inode.c:593
 hugetlbfs_punch_hole fs/hugetlbfs/inode.c:716 [inline]
 hugetlbfs_fallocate+0xbc7/0x1100 fs/hugetlbfs/inode.c:742
 vfs_fallocate+0x669/0x7e0 fs/open.c:342
 madvise_remove mm/madvise.c:1049 [inline]
 madvise_vma_behavior+0x3254/0x3af0 mm/madvise.c:1346
 madvise_walk_vmas+0x51c/0xa30 mm/madvise.c:1669
 madvise_do_behavior+0x38e/0x550 mm/madvise.c:1885
 do_madvise+0x1bc/0x270 mm/madvise.c:1978
 __do_sys_madvise mm/madvise.c:1987 [inline]
 __se_sys_madvise mm/madvise.c:1985 [inline]
 __ia32_sys_madvise+0xa7/0xc0 mm/madvise.c:1985
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fa6539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f47fb55c EFLAGS: 00000206 ORIG_RAX: 00000000000000db
RAX: ffffffffffffffda RBX: 0000000080000000 RCX: 0000000000600002
RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:filemap_unaccount_folio+0x715/0x790 mm/filemap.c:154
Code: a3 c9 ff 48 89 df 48 c7 c6 e0 3b 94 8b e8 f3 f0 31 ff 90 0f 0b e8 bb a3 c9 ff 48 89 df 48 c7 c6 c0 3a 94 8b e8 dc f0 31 ff 90 <0f> 0b e8 a4 a3 c9 ff 48 89 df 48 c7 c6 e0 3b 94 8b e8 c5 f0 31 ff
RSP: 0018:ffffc9000ac6ede0 EFLAGS: 00010046
RAX: 4c7b66f2d5fa4c00 RBX: ffffea0008eb0000 RCX: 4c7b66f2d5fa4c00
RDX: 0000000000000005 RSI: ffffffff8dba8965 RDI: ffff888027329e00
RBP: 0000000000000001 R08: ffff8880b8724253 R09: 1ffff110170e484a
R10: dffffc0000000000 R11: ffffed10170e484b R12: 0000000000000040
R13: 1ffffd40011d6000 R14: 1ffffd40011d6001 R15: ffffea0008eb0008
FS:  0000000000000000(0000) GS:ffff888125d15000(0063) knlGS:00000000f47fbb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000800bd01c CR3: 000000007870a000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   4:	10 07                	adc    %al,(%rdi)
   6:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   a:	10 08                	adc    %cl,(%rax)
   c:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  20:	00 51 52             	add    %dl,0x52(%rcx)
  23:	55                   	push   %rbp
  24:	89 e5                	mov    %esp,%ebp
  26:	0f 34                	sysenter
  28:	cd 80                	int    $0x80
* 2a:	5d                   	pop    %rbp <-- trapping instruction
  2b:	5a                   	pop    %rdx
  2c:	59                   	pop    %rcx
  2d:	c3                   	ret
  2e:	90                   	nop
  2f:	90                   	nop
  30:	90                   	nop
  31:	90                   	nop
  32:	90                   	nop
  33:	90                   	nop
  34:	90                   	nop
  35:	90                   	nop
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop