------------[ cut here ]------------
!reader
WARNING: kernel/trace/ring_buffer.c:8005 at ring_buffer_map_get_reader+0x5f3/0x930 kernel/trace/ring_buffer.c:8005, CPU#3: syz.5.2042/13948
Modules linked in:
CPU: 3 UID: 0 PID: 13948 Comm: syz.5.2042 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:ring_buffer_map_get_reader+0x5f3/0x930 kernel/trace/ring_buffer.c:8005
Code: ff 48 89 df e8 be 20 fe ff 48 89 c5 e8 76 86 fb ff 48 85 ed 0f 85 9f fc ff ff 4c 8b 74 24 58 4c 8b 7c 24 60 e8 5e 86 fb ff 90 <0f> 0b 90 e8 55 86 fb ff 49 8d bf d0 01 00 00 48 b8 00 00 00 00 00
RSP: 0018:ffffc90005c7fd98 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff88801c0e5000 RCX: 0000000000000001
RDX: ffff8880458dcb00 RSI: ffffffff8210ac52 RDI: ffff8880458dcb00
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88801c0e50b0 R12: ffff88801c0e50b8
R13: dffffc0000000000 R14: ffff88801c0e5198 R15: ffff88801c0ab800
FS:  00007fae5db0f6c0(0000) GS:ffff8880d5e52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000380 CR3: 000000003935e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 tracing_buffers_ioctl+0x2e6/0x3d0 kernel/trace/trace.c:7381
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fae5cb9e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fae5db0f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fae5ce25fa0 RCX: 00007fae5cb9e159
RDX: 0000000000000000 RSI: 0000000000005220 RDI: 0000000000000006
RBP: 00007fae5cc3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fae5ce26038 R14: 00007fae5ce25fa0 R15: 00007ffd6ef00358
 </TASK>