BUG: kernel NULL pointer dereference, address: 0000000000000038
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 2c141067 P4D 2c141067 PUD 0 
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Tainted: G             L       syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:slab_obj_exts mm/slab.h:701 [inline]
RIP: 0010:memcg_slab_free_hook mm/slub.c:2572 [inline]
RIP: 0010:__rcu_free_sheaf_prepare+0xc4/0x300 mm/slub.c:3038
Code: c1 e0 06 48 03 05 7c 02 13 0c 48 8b 58 08 48 89 da 83 e2 01 48 83 ea 01 48 09 d3 48 21 c3 31 c0 80 7b 33 f5 48 0f 45 d8 66 90 <4c> 8b 43 38 4d 85 c0 0f 85 37 01 00 00 49 8b 2c 24 41 8b 77 1c 48
RSP: 0018:ffffc90000648d80 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000002e
RDX: ffffffffffffffff RSI: ffffffff8e6212d7 RDI: ffff888060a4fd00
RBP: ffff888060a11e80 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000000ad58 R12: ffff88804be6bc20
R13: 0000000000000000 R14: ffff88804be6bc00 R15: ffff88801d4428c0
FS:  0000000000000000(0000) GS:ffff8880d4690000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 0000000051b51000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_free_sheaf+0x1a/0xe0 mm/slub.c:6182
 rcu_do_batch kernel/rcu/tree.c:2650 [inline]
 rcu_core+0x5f0/0x1220 kernel/rcu/tree.c:2919
 handle_softirqs+0x216/0xa20 kernel/softirq.c:669
 __do_softirq kernel/softirq.c:703 [inline]
 invoke_softirq kernel/softirq.c:542 [inline]
 __irq_exit_rcu+0x178/0x220 kernel/softirq.c:786
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:809
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 77 a3 02 e9 43 61 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d c3 0d 20 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000187e00 EFLAGS: 00000202
RAX: 00000000000ff1a7 RBX: ffff888020ac4b00 RCX: ffffffff8bebb325
RDX: 0000000000000001 RSI: ffffffff8e6212d7 RDI: ffffffff8c833580
RBP: ffffed1004158960 R08: 0000000000000001 R09: ffffed100d446825
R10: ffff88806a23412b R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000030fc4 R15: dffffc0000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:768
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x158
 </TASK>
Modules linked in:
CR2: 0000000000000038
---[ end trace 0000000000000000 ]---
RIP: 0010:slab_obj_exts mm/slab.h:701 [inline]
RIP: 0010:memcg_slab_free_hook mm/slub.c:2572 [inline]
RIP: 0010:__rcu_free_sheaf_prepare+0xc4/0x300 mm/slub.c:3038
Code: c1 e0 06 48 03 05 7c 02 13 0c 48 8b 58 08 48 89 da 83 e2 01 48 83 ea 01 48 09 d3 48 21 c3 31 c0 80 7b 33 f5 48 0f 45 d8 66 90 <4c> 8b 43 38 4d 85 c0 0f 85 37 01 00 00 49 8b 2c 24 41 8b 77 1c 48
RSP: 0018:ffffc90000648d80 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000002e
RDX: ffffffffffffffff RSI: ffffffff8e6212d7 RDI: ffff888060a4fd00
RBP: ffff888060a11e80 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000000ad58 R12: ffff88804be6bc20
R13: 0000000000000000 R14: ffff88804be6bc00 R15: ffff88801d4428c0
FS:  0000000000000000(0000) GS:ffff8880d4690000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 0000000051b51000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	c1 e0 06             	shl    $0x6,%eax
   3:	48 03 05 7c 02 13 0c 	add    0xc13027c(%rip),%rax        # 0xc130286
   a:	48 8b 58 08          	mov    0x8(%rax),%rbx
   e:	48 89 da             	mov    %rbx,%rdx
  11:	83 e2 01             	and    $0x1,%edx
  14:	48 83 ea 01          	sub    $0x1,%rdx
  18:	48 09 d3             	or     %rdx,%rbx
  1b:	48 21 c3             	and    %rax,%rbx
  1e:	31 c0                	xor    %eax,%eax
  20:	80 7b 33 f5          	cmpb   $0xf5,0x33(%rbx)
  24:	48 0f 45 d8          	cmovne %rax,%rbx
  28:	66 90                	xchg   %ax,%ax
* 2a:	4c 8b 43 38          	mov    0x38(%rbx),%r8 <-- trapping instruction
  2e:	4d 85 c0             	test   %r8,%r8
  31:	0f 85 37 01 00 00    	jne    0x16e
  37:	49 8b 2c 24          	mov    (%r12),%rbp
  3b:	41 8b 77 1c          	mov    0x1c(%r15),%esi
  3f:	48                   	rex.W