R13: 00007fc5fda75038 R14: 00007fc5fda74fa0 R15: 00007ffd3d7dbc58
 </TASK>
kobject_add_internal failed for iosched with -EEXIST, don't try to register things with the same name in the same directory.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4549 at block/genhd.c:547 device_add_disk+0x731/0xd00 block/genhd.c:545
Modules linked in:
CPU: 0 PID: 4549 Comm: syz.0.68 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:device_add_disk+0x731/0xd00 block/genhd.c:547
Code: b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 a9 04 00 00 8b 33 48 c7 c7 80 f1 90 8c e8 76 3e 37 00 eb 05 e8 9f a8 a6 fd <0f> 0b 41 bd 01 00 00 00 44 89 e8 48 83 c4 50 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000333fa70 EFLAGS: 00010246
RAX: ffffffff83d25411 RBX: ffff888060a0a400 RCX: 0000000000080000
RDX: ffffc90005871000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 00000000000000fa R08: ffffc9000333f8e7 R09: 1ffff92000667f1c
R10: dffffc0000000000 R11: fffff52000667f1d R12: ffff888144b84320
R13: ffff8880170a3b00 R14: 1ffff1100c141480 R15: ffff8880170a3b00
FS:  00007fc5fba456c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556b05f32090 CR3: 00000000500ef000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 null_add_dev+0xe81/0x1630 drivers/block/null_blk/main.c:1913
 nullb_device_power_store+0x241/0x370 drivers/block/null_blk/main.c:390
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x748/0xd70 fs/read_write.c:594
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc5fd7ed0d9
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:00007fc5fba45028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc5fda74fa0 RCX: 00007fc5fd7ed0d9
RDX: 0000000000000002 RSI: 0000200000000200 RDI: 0000000000000003
RBP: 00007fc5fd884024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc5fda75038 R14: 00007fc5fda74fa0 R15: 00007ffd3d7dbc58
 </TASK>