general protection fault, probably for non-canonical address 0xdffffc0000000084: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000420-0x0000000000000427] CPU: 1 PID: 36 Comm: khugepaged Not tainted 6.8.0-rc2-syzkaller-00199-g021533194476 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:khugepaged_scan_mm_slot mm/khugepaged.c:2375 [inline] RIP: 0010:khugepaged_do_scan mm/khugepaged.c:2508 [inline] RIP: 0010:khugepaged+0x5bf/0x1620 mm/khugepaged.c:2564 Code: 00 89 de e8 e3 02 a0 ff 85 db 0f 84 68 0d 00 00 e8 f6 07 a0 ff 49 8d 7e 20 48 b9 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 21 0f 00 00 49 8d 7e 78 49 8b 6e 20 48 b9 00 00 RSP: 0018:ffffc90000acfcf8 EFLAGS: 00010217 RAX: 0000000000000084 RBX: 0000000000000001 RCX: dffffc0000000000 RDX: ffff88801b6c8000 RSI: ffffffff81ec61ca RDI: 0000000000000426 RBP: 0000000020000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 0000000020400000 R13: 0000000000000003 R14: 0000000000000406 R15: 1ffff92000159faf FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcb49ad56c6 CR3: 000000004c8d0000 CR4: 0000000000350ef0 Call Trace: kthread+0x2c9/0x3b0 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:khugepaged_scan_mm_slot mm/khugepaged.c:2375 [inline] RIP: 0010:khugepaged_do_scan mm/khugepaged.c:2508 [inline] RIP: 0010:khugepaged+0x5bf/0x1620 mm/khugepaged.c:2564 Code: 00 89 de e8 e3 02 a0 ff 85 db 0f 84 68 0d 00 00 e8 f6 07 a0 ff 49 8d 7e 20 48 b9 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 21 0f 00 00 49 8d 7e 78 49 8b 6e 20 48 b9 00 00 RSP: 0018:ffffc90000acfcf8 EFLAGS: 00010217 RAX: 0000000000000084 RBX: 0000000000000001 RCX: dffffc0000000000 RDX: ffff88801b6c8000 RSI: ffffffff81ec61ca RDI: 0000000000000426 RBP: 0000000020000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 0000000020400000 R13: 0000000000000003 R14: 0000000000000406 R15: 1ffff92000159faf FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9a414b4440 CR3: 000000002d3ae000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 00 89 de e8 e3 02 add %cl,0x2e3e8de(%rcx) 6: a0 ff 85 db 0f 84 68 movabs 0xd68840fdb85ff,%al d: 0d 00 f: 00 e8 add %ch,%al 11: f6 07 a0 testb $0xa0,(%rdi) 14: ff 49 8d decl -0x73(%rcx) 17: 7e 20 jle 0x39 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 21 0f 00 00 jne 0xf55 34: 49 8d 7e 78 lea 0x78(%r14),%rdi 38: 49 8b 6e 20 mov 0x20(%r14),%rbp 3c: 48 rex.W 3d: b9 .byte 0xb9