Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 UID: 0 PID: 7256 Comm: syz.0.455 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:task_cpu include/linux/sched.h:2268 [inline]
RIP: 0010:is_task_rq_idle kernel/sched/core.c:6169 [inline]
RIP: 0010:cookie_equals kernel/sched/core.c:6174 [inline]
RIP: 0010:pick_next_task kernel/sched/core.c:6355 [inline]
RIP: 0010:__schedule+0x4030/0x5550 kernel/sched/core.c:7143
Code: 24 80 00 00 00 e8 c0 87 fc f6 48 8b 84 24 80 00 00 00 48 8b 18 4c 8d 7b 14 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 87 04 00 00 45 8b 3f 49 83 ff 08 0f 83 98
RSP: 0018:ffffc900070f7520 EFLAGS: 00010003
RAX: 0000000000000002 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff8880b8620c60
RBP: ffffc900070f7718 R08: ffffffff8f8d5cf7 R09: 1ffffffff1f1ab9e
R10: dffffc0000000000 R11: ffffffff81999eb0 R12: ffff8880b863c658
R13: ffff888125ebb000 R14: 1ffff110170c7922 R15: 0000000000000014
FS:  00007f23853966c0(0000) GS:ffff888125ebb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2385375d58 CR3: 000000003f24c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __schedule_loop kernel/sched/core.c:7307 [inline]
 schedule_rtlock+0x30/0x70 kernel/sched/core.c:7386
 rtlock_slowlock_locked+0x3635/0x3c80 kernel/locking/rtmutex.c:1894
 rtlock_slowlock kernel/locking/rtmutex.c:1921 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57
 spin_lock_irq include/linux/spinlock_rt.h:96 [inline]
 snd_rawmidi_write+0x4d5/0xc10 sound/core/rawmidi.c:1622
 do_loop_readv_writev fs/read_write.c:851 [inline]
 vfs_writev+0x4c6/0x9a0 fs/read_write.c:1060
 do_writev+0x15a/0x2e0 fs/read_write.c:1104
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f238713ce59
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:00007f2385396028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f23873b5fa0 RCX: 00007f238713ce59
RDX: 000000000000002f RSI: 0000200000000840 RDI: 0000000000000007
RBP: 00007f23871d2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f23873b6038 R14: 00007f23873b5fa0 R15: 00007fff1744de48
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:task_cpu include/linux/sched.h:2268 [inline]
RIP: 0010:is_task_rq_idle kernel/sched/core.c:6169 [inline]
RIP: 0010:cookie_equals kernel/sched/core.c:6174 [inline]
RIP: 0010:pick_next_task kernel/sched/core.c:6355 [inline]
RIP: 0010:__schedule+0x4030/0x5550 kernel/sched/core.c:7143
Code: 24 80 00 00 00 e8 c0 87 fc f6 48 8b 84 24 80 00 00 00 48 8b 18 4c 8d 7b 14 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 87 04 00 00 45 8b 3f 49 83 ff 08 0f 83 98
RSP: 0018:ffffc900070f7520 EFLAGS: 00010003
RAX: 0000000000000002 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff8880b8620c60
RBP: ffffc900070f7718 R08: ffffffff8f8d5cf7 R09: 1ffffffff1f1ab9e
R10: dffffc0000000000 R11: ffffffff81999eb0 R12: ffff8880b863c658
R13: ffff888125ebb000 R14: 1ffff110170c7922 R15: 0000000000000014
FS:  00007f23853966c0(0000) GS:ffff888125ebb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2385375d58 CR3: 000000003f24c000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	24 80                	and    $0x80,%al
   2:	00 00                	add    %al,(%rax)
   4:	00 e8                	add    %ch,%al
   6:	c0 87 fc f6 48 8b 84 	rolb   $0x84,-0x74b70904(%rdi)
   d:	24 80                	and    $0x80,%al
   f:	00 00                	add    %al,(%rax)
  11:	00 48 8b             	add    %cl,-0x75(%rax)
  14:	18 4c 8d 7b          	sbb    %cl,0x7b(%rbp,%rcx,4)
  18:	14 4c                	adc    $0x4c,%al
  1a:	89 f8                	mov    %edi,%eax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 87 04 00 00    	jne    0x4bd
  36:	45 8b 3f             	mov    (%r15),%r15d
  39:	49 83 ff 08          	cmp    $0x8,%r15
  3d:	0f                   	.byte 0xf
  3e:	83                   	.byte 0x83
  3f:	98                   	cwtl