Oops: general protection fault, probably for non-canonical address 0xdffffc0000000084: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000420-0x0000000000000427]
CPU: 0 UID: 0 PID: 47 Comm: khugepaged Not tainted 6.12.0-rc1-syzkaller-00125-g0c559323bbaa #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:khugepaged_scan_mm_slot mm/khugepaged.c:2383 [inline]
RIP: 0010:khugepaged_do_scan mm/khugepaged.c:2515 [inline]
RIP: 0010:khugepaged+0xae0/0x15f0 mm/khugepaged.c:2571
Code: ed c7 04 24 01 00 00 00 45 31 ff e9 9b fd ff ff e8 15 3d 98 ff 49 8d 7f 20 48 b9 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 d4 09 00 00 49 8d 7f 70 49 8b 6f 20 48 b9 00 00
RSP: 0018:ffffc900006dfcd0 EFLAGS: 00010207
RAX: 0000000000000084 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88801e62c880 RSI: ffffffff81f4718b RDI: 0000000000000426
RBP: 00000000100400fb R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000200
R13: 0000000000000003 R14: 1ffff920000dbfab R15: 0000000000000406
FS:  0000000000000000(0000) GS:ffff88802b400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000577194ac CR3: 000000005f6bc000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000000f
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:khugepaged_scan_mm_slot mm/khugepaged.c:2383 [inline]
RIP: 0010:khugepaged_do_scan mm/khugepaged.c:2515 [inline]
RIP: 0010:khugepaged+0xae0/0x15f0 mm/khugepaged.c:2571
Code: ed c7 04 24 01 00 00 00 45 31 ff e9 9b fd ff ff e8 15 3d 98 ff 49 8d 7f 20 48 b9 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 d4 09 00 00 49 8d 7f 70 49 8b 6f 20 48 b9 00 00
RSP: 0018:ffffc900006dfcd0 EFLAGS: 00010207
RAX: 0000000000000084 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88801e62c880 RSI: ffffffff81f4718b RDI: 0000000000000426
RBP: 00000000100400fb R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000200
R13: 0000000000000003 R14: 1ffff920000dbfab R15: 0000000000000406
FS:  0000000000000000(0000) GS:ffff88802b600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f73ce1a4 CR3: 000000005f6bc000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	ed                   	in     (%dx),%eax
   1:	c7 04 24 01 00 00 00 	movl   $0x1,(%rsp)
   8:	45 31 ff             	xor    %r15d,%r15d
   b:	e9 9b fd ff ff       	jmp    0xfffffdab
  10:	e8 15 3d 98 ff       	call   0xff983d2a
  15:	49 8d 7f 20          	lea    0x20(%r15),%rdi
  19:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  20:	fc ff df
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	0f 85 d4 09 00 00    	jne    0xa08
  34:	49 8d 7f 70          	lea    0x70(%r15),%rdi
  38:	49 8b 6f 20          	mov    0x20(%r15),%rbp
  3c:	48                   	rex.W
  3d:	b9                   	.byte 0xb9