Oops: general protection fault, probably for non-canonical address 0xdffffc0000000084: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000420-0x0000000000000427]
CPU: 1 UID: 0 PID: 37 Comm: khugepaged Not tainted 6.12.0-rc5-syzkaller-00005-ge42b1a9a2557 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:khugepaged_scan_mm_slot mm/khugepaged.c:2383 [inline]
RIP: 0010:khugepaged_do_scan mm/khugepaged.c:2515 [inline]
RIP: 0010:khugepaged+0x771/0x1dc0 mm/khugepaged.c:2571
Code: 8b 1b be 00 00 00 01 48 21 de 31 ff e8 c8 ea 92 ff b8 00 00 00 01 48 21 c3 0f 85 4a 0d 00 00 49 8d 7d 20 48 89 f8 48 c1 e8 03 <42> 80 3c 38 00 74 05 e8 d3 7e f9 ff 4d 8b 75 20 49 8d 5d 70 48 89
RSP: 0018:ffffc90000ad7bc0 EFLAGS: 00010207
RAX: 0000000000000084 RBX: 0000000000000000 RCX: ffff88801fefda00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000426
RBP: ffffc90000ad7ed0 R08: ffffffff8201f248 R09: 1ffff1100358ea2e
R10: dffffc0000000000 R11: ffffed100358ea2f R12: ffff88801ac74a00
R13: 0000000000000406 R14: 00000000180400fb R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb17451ed58 CR3: 0000000064988000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/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+0x771/0x1dc0 mm/khugepaged.c:2571
Code: 8b 1b be 00 00 00 01 48 21 de 31 ff e8 c8 ea 92 ff b8 00 00 00 01 48 21 c3 0f 85 4a 0d 00 00 49 8d 7d 20 48 89 f8 48 c1 e8 03 <42> 80 3c 38 00 74 05 e8 d3 7e f9 ff 4d 8b 75 20 49 8d 5d 70 48 89
RSP: 0018:ffffc90000ad7bc0 EFLAGS: 00010207
RAX: 0000000000000084 RBX: 0000000000000000 RCX: ffff88801fefda00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000426
RBP: ffffc90000ad7ed0 R08: ffffffff8201f248 R09: 1ffff1100358ea2e
R10: dffffc0000000000 R11: ffffed100358ea2f R12: ffff88801ac74a00
R13: 0000000000000406 R14: 00000000180400fb R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555594c407d0 CR3: 0000000064988000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	8b 1b                	mov    (%rbx),%ebx
   2:	be 00 00 00 01       	mov    $0x1000000,%esi
   7:	48 21 de             	and    %rbx,%rsi
   a:	31 ff                	xor    %edi,%edi
   c:	e8 c8 ea 92 ff       	call   0xff92ead9
  11:	b8 00 00 00 01       	mov    $0x1000000,%eax
  16:	48 21 c3             	and    %rax,%rbx
  19:	0f 85 4a 0d 00 00    	jne    0xd69
  1f:	49 8d 7d 20          	lea    0x20(%r13),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 d3 7e f9 ff       	call   0xfff97f09
  36:	4d 8b 75 20          	mov    0x20(%r13),%r14
  3a:	49 8d 5d 70          	lea    0x70(%r13),%rbx
  3e:	48                   	rex.W
  3f:	89                   	.byte 0x89