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WARNING: CPU: 1 PID: 4976 at block/genhd.c:523 __device_add_disk+0xb76/0xd10 block/genhd.c:523
Modules linked in:
CPU: 0 PID: 4976 Comm: syz-executor.0 Tainted: G        W         5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__device_add_disk+0xb76/0xd10 block/genhd.c:523
Code: fb ff ff 4c 89 ef 89 44 24 28 e8 95 bb f9 fd 8b 44 24 28 e9 7a fb ff ff 4c 89 ef e8 14 bb f9 fd e9 e0 fb ff ff e8 6a fd b3 fd <0f> 0b e9 97 fb ff ff 4c 89 ff e8 2b bb f9 fd e9 b1 f6 ff ff 48 8b
RSP: 0018:ffffc9000e44fd98 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff8880a0a75800 RCX: ffffc900018e2000
RDX: 0000000000040000 RSI: ffffffff83c18cc6 RDI: 0000000000000003
RBP: ffff888081e9d000 R08: 0000000000000000 R09: ffffffff8c2c0473
R10: ffffffff83c18858 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8880a0a75c9c R14: ffff888081e9d0a0 R15: 0000000000000000
FS:  00007fee1b854700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7dad8792c8 CR3: 000000009f156000 CR4: 0000000000350ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 add_disk include/linux/genhd.h:217 [inline]
 loop_add+0x68f/0x8f0 drivers/block/loop.c:2328
 loop_control_ioctl drivers/block/loop.c:2421 [inline]
 loop_control_ioctl+0x16c/0x480 drivers/block/loop.c:2403
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fee1b854188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000007
RBP: 00007fee1b8541d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffe2c09936f R14: 00007fee1b854300 R15: 0000000000022000