smpboot: CPU0: Intel(R) Xeon(R) CPU @ 2.80GHz (family: 0x6, model: 0x55, stepping: 0x7)
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:kfence_guarded_alloc+0x643/0xc70
Code: 41 c1 e5 18 bf 00 00 00 f5 44 89 ee e8 a6 67 9c ff 45 31 f6 41 81 fd 00 00 00 f5 4c 0f 44 f3 49 8d 7e 08 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 f1 cb ff ff 4c 8b 6c 24 18 4d 89 6e 08 49
RSP: 0000:ffffc90000047740 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffffea0004d90080 RCX: 0000000000000000
RDX: ffff88801c2e8000 RSI: 00000000ff000000 RDI: 0000000000000008
RBP: ffffc90000047850 R08: ffffffff99b2201b R09: 1ffffffff3364403
R10: dffffc0000000000 R11: fffffbfff3364404 R12: dffffc0000000000
R13: 00000000ff000000 R14: 0000000000000000 R15: ffff88813fec7068
FS:  0000000000000000(0000) GS:ffff8880b861c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88813ffff000 CR3: 000000000df36000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __kfence_alloc+0x385/0x3b0
 __kmalloc_noprof+0x440/0x4f0
 __alloc_workqueue+0x103/0x1b70
 alloc_workqueue_noprof+0xd4/0x210
 init_mm_internals+0x17/0x140
 kernel_init_freeable+0x307/0x4b0
 kernel_init+0x1d/0x1d0
 ret_from_fork+0x3f9/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kfence_guarded_alloc+0x643/0xc70
Code: 41 c1 e5 18 bf 00 00 00 f5 44 89 ee e8 a6 67 9c ff 45 31 f6 41 81 fd 00 00 00 f5 4c 0f 44 f3 49 8d 7e 08 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 f1 cb ff ff 4c 8b 6c 24 18 4d 89 6e 08 49
RSP: 0000:ffffc90000047740 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffffea0004d90080 RCX: 0000000000000000
RDX: ffff88801c2e8000 RSI: 00000000ff000000 RDI: 0000000000000008
RBP: ffffc90000047850 R08: ffffffff99b2201b R09: 1ffffffff3364403
R10: dffffc0000000000 R11: fffffbfff3364404 R12: dffffc0000000000
R13: 00000000ff000000 R14: 0000000000000000 R15: ffff88813fec7068
FS:  0000000000000000(0000) GS:ffff8880b861c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88813ffff000 CR3: 000000000df36000 CR4: 0000000000350ef0