general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 6226 Comm: syz.1.120 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:percpu_ref_kill_and_confirm+0xf1/0x130 lib/percpu-refcount.c:392
Code: 01 4c 8d 63 08 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 ee ef ac fd 4d 8b 24 24 49 83 c4 08 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 d0 ef ac fd 49 8b 14 24 48 c7 c7
RSP: 0018:ffffc9000babf9c8 EFLAGS: 00010002
RAX: 0000000000000001 RBX: ffff888026664040 RCX: 0000000000080000
RDX: ffffc9000cf92000 RSI: 0000000000001493 RDI: 0000000000001494
RBP: 1ffff11004ccc808 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001757f14 R12: 0000000000000008
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000a06
FS:  00007f01a512d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c42812b CR3: 0000000023af5000 CR4: 00000000003526e0
Call Trace:
 <TASK>
 percpu_ref_kill include/linux/percpu-refcount.h:149 [inline]
 mddev_suspend+0x1b0/0x5b0 drivers/md/md.c:450
 mddev_create_serial_pool+0x282/0x470 drivers/md/md.c:219
 backlog_store+0x382/0x4f0 drivers/md/md-bitmap.c:2592
 md_attr_store+0x196/0x380 drivers/md/md.c:5630
 kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f01a419e159
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:00007f01a512d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f01a4425fa0 RCX: 00007f01a419e159
RDX: 0000000000000005 RSI: 0000200000000e00 RDI: 0000000000000009
RBP: 00007f01a4235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f01a4426038 R14: 00007f01a4425fa0 R15: 00007ffe161ab678
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:percpu_ref_kill_and_confirm+0xf1/0x130 lib/percpu-refcount.c:392
Code: 01 4c 8d 63 08 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 ee ef ac fd 4d 8b 24 24 49 83 c4 08 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 d0 ef ac fd 49 8b 14 24 48 c7 c7
RSP: 0018:ffffc9000babf9c8 EFLAGS: 00010002
RAX: 0000000000000001 RBX: ffff888026664040 RCX: 0000000000080000
RDX: ffffc9000cf92000 RSI: 0000000000001493 RDI: 0000000000001494
RBP: 1ffff11004ccc808 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001757f14 R12: 0000000000000008
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000a06
FS:  00007f01a512d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c42812b CR3: 0000000023af5000 CR4: 00000000003526e0
----------------
Code disassembly (best guess):
   0:	01 4c 8d 63          	add    %ecx,0x63(%rbp,%rcx,4)
   4:	08 4c 89 e0          	or     %cl,-0x20(%rcx,%rcx,4)
   8:	48 c1 e8 03          	shr    $0x3,%rax
   c:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  11:	74 08                	je     0x1b
  13:	4c 89 e7             	mov    %r12,%rdi
  16:	e8 ee ef ac fd       	call   0xfdacf009
  1b:	4d 8b 24 24          	mov    (%r12),%r12
  1f:	49 83 c4 08          	add    $0x8,%r12
  23:	4c 89 e0             	mov    %r12,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 e7             	mov    %r12,%rdi
  34:	e8 d0 ef ac fd       	call   0xfdacf009
  39:	49 8b 14 24          	mov    (%r12),%rdx
  3d:	48                   	rex.W
  3e:	c7                   	.byte 0xc7
  3f:	c7                   	.byte 0xc7