__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
 el0_svc_common.constprop.0+0xf0/0x2c0 arch/arm64/kernel/syscall.c:129
 do_el0_svc+0xa4/0xd0 arch/arm64/kernel/syscall.c:168
 el0_svc+0x24/0x3c arch/arm64/kernel/entry-common.c:416
 el0_sync_handler+0x1a4/0x1b0 arch/arm64/kernel/entry-common.c:432
 el0_sync+0x170/0x180 arch/arm64/kernel/entry.S:699
------------[ cut here ]------------
WARNING: CPU: 0 PID: 29557 at block/genhd.c:617 register_disk block/genhd.c:512 [inline]
WARNING: CPU: 0 PID: 29557 at block/genhd.c:617 __device_add_disk+0xbcc/0xea0 block/genhd.c:621
Modules linked in:
CPU: 0 PID: 29557 Comm: syz-executor.1 Not tainted 5.12.0-rc7-syzkaller-00002-g89698becf06d #0
Hardware name: linux,dummy-virt (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--)
pc : __device_add_disk+0xbcc/0xea0 block/genhd.c:617
lr : __device_add_disk+0xb30/0xea0 block/genhd.c:616
sp : ffff000009737b30
x29: ffff000009737b30 x28: ffff0000166a6000 
x27: ffff000009ab0800 x26: ffff000008c117d0 
x25: 1fffe00001356101 x24: ffff000009ab0804 
x23: 1fffe00001356114 x22: ffff000009ab08a0 
x21: ffff8000146de4e0 x20: 1fffe00001356110 
x19: 1fffe000012e6f80 x18: fffffbffeff1f9c8 
x17: 0000000000000000 x16: 0000000000000002 
x15: ffff80001646a220 x14: 1fffe000012e6de6 
x13: 0000000000000001 x12: ffff700002c36d23 
x11: 1ffff00002c36d22 x10: ffff700002c36d22 
x9 : dfff800000000000 x8 : ffff8000161b6913 
x7 : 0000000000000001 x6 : 00008ffffd3c92de 
x5 : ffff8000161b6910 x4 : 0000000000000dc0 
x3 : 0000000000000000 x2 : 0000000000000000 
x1 : ffff00000e5e0000 x0 : fffffffffffffff4 
Call trace:
 register_disk block/genhd.c:512 [inline]
 __device_add_disk+0xbcc/0xea0 block/genhd.c:621
 device_add_disk+0x14/0x20 block/genhd.c:639
 add_disk include/linux/genhd.h:231 [inline]
 loop_add+0x52c/0x720 drivers/block/loop.c:2172
 loop_control_ioctl drivers/block/loop.c:2268 [inline]
 loop_control_ioctl+0x134/0x3a0 drivers/block/loop.c:2250
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __arm64_sys_ioctl+0x120/0x18c fs/ioctl.c:739
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
 el0_svc_common.constprop.0+0xf0/0x2c0 arch/arm64/kernel/syscall.c:129
 do_el0_svc+0xa4/0xd0 arch/arm64/kernel/syscall.c:168
 el0_svc+0x24/0x3c arch/arm64/kernel/entry-common.c:416
 el0_sync_handler+0x1a4/0x1b0 arch/arm64/kernel/entry-common.c:432
 el0_sync+0x170/0x180 arch/arm64/kernel/entry.S:699
irq event stamp: 5414
hardirqs last  enabled at (5413): [<ffff8000143ef8e8>] exit_to_kernel_mode+0x38/0x230 arch/arm64/kernel/entry-common.c:59
hardirqs last disabled at (5414): [<ffff8000143eff44>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:237
softirqs last  enabled at (5402): [<ffff8000100109e0>] _stext+0x9e0/0x1084
softirqs last disabled at (5391): [<ffff80001015a03c>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
softirqs last disabled at (5391): [<ffff80001015a03c>] invoke_softirq kernel/softirq.c:228 [inline]
softirqs last disabled at (5391): [<ffff80001015a03c>] __irq_exit_rcu+0x46c/0x510 kernel/softirq.c:422
---[ end trace 5afe22bb3a30de09 ]---