------------[ cut here ]------------
failed to allocate ring buffer on CPU 1
WARNING: kernel/trace/ring_buffer.c:8109 at trace_rb_cpu_prepare+0x463/0x520 kernel/trace/ring_buffer.c:8109, CPU#3: syz.3.455/7391
Modules linked in:
CPU: 3 UID: 0 PID: 7391 Comm: syz.3.455 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:trace_rb_cpu_prepare+0x465/0x520 kernel/trace/ring_buffer.c:8109
Code: 48 c1 ea 03 80 3c 02 00 0f 84 bc fc ff ff 48 8b 3c 24 e8 8e fd 6d 00 e9 ae fc ff ff e8 54 7f fb ff 48 8d 3d cd 3a 39 0f 89 ee <67> 48 0f b9 3a bb f4 ff ff ff e9 d3 fd ff ff 4c 89 ef e8 64 fd 6d
RSP: 0000:ffffc90003ee78b8 EFLAGS: 00010283
RAX: 0000000000030bb9 RBX: ffff88805fafc8b8 RCX: ffffc90007862000
RDX: 0000000000080000 RSI: 0000000000000001 RDI: ffffffff91496170
RBP: 0000000000000001 R08: ffff88806c483688 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001
R13: ffff88805fafc810 R14: 0000000000000162 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888096c52000(0063) knlGS:00000000f547db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000008000b000 CR3: 000000004c936000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 cpuhp_invoke_callback+0x205/0x9a0 kernel/cpu.c:204
 cpuhp_issue_call+0x1b8/0x970 kernel/cpu.c:2354
 __cpuhp_state_add_instance_cpuslocked+0x2d7/0x400 kernel/cpu.c:2423
 __cpuhp_state_add_instance+0xda/0x2e0 kernel/cpu.c:2444
 cpuhp_state_add_instance include/linux/cpuhotplug.h:383 [inline]
 alloc_buffer+0x6f8/0x1690 kernel/trace/ring_buffer.c:2916
 __ring_buffer_alloc+0x2d/0x40 kernel/trace/ring_buffer.c:2958
 allocate_trace_buffer+0x150/0xa30 kernel/trace/trace.c:8509
 allocate_trace_buffers kernel/trace/trace.c:8542 [inline]
 trace_array_create_systems+0x582/0xc30 kernel/trace/trace.c:8720
 trace_array_create kernel/trace/trace.c:8763 [inline]
 instance_mkdir+0xca/0x140 kernel/trace/trace.c:8778
 tracefs_syscall_mkdir+0x10e/0x180 fs/tracefs/inode.c:121
 vfs_mkdir+0x364/0x850 fs/namei.c:5410
 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5443
 __do_sys_mkdirat fs/namei.c:5464 [inline]
 __se_sys_mkdirat fs/namei.c:5461 [inline]
 __ia32_sys_mkdirat+0x88/0xc0 fs/namei.c:5461
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf708efec
Code: Unable to access opcode bytes at 0xf708efc2.
RSP: 002b:00000000f547d50c EFLAGS: 00000292 ORIG_RAX: 0000000000000128
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 0000000080000140
RDX: 00000000000001ff RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 c1 ea 03          	shr    $0x3,%rdx
   4:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   8:	0f 84 bc fc ff ff    	je     0xfffffcca
   e:	48 8b 3c 24          	mov    (%rsp),%rdi
  12:	e8 8e fd 6d 00       	call   0x6dfda5
  17:	e9 ae fc ff ff       	jmp    0xfffffcca
  1c:	e8 54 7f fb ff       	call   0xfffb7f75
  21:	48 8d 3d cd 3a 39 0f 	lea    0xf393acd(%rip),%rdi        # 0xf393af5
  28:	89 ee                	mov    %ebp,%esi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	bb f4 ff ff ff       	mov    $0xfffffff4,%ebx
  34:	e9 d3 fd ff ff       	jmp    0xfffffe0c
  39:	4c 89 ef             	mov    %r13,%rdi
  3c:	e8                   	.byte 0xe8
  3d:	64 fd                	fs std
  3f:	6d                   	insl   (%dx),%es:(%rdi)