------------[ cut here ]------------ kobject: '(null)' (ffff88801211e0f0): is not initialized, yet kobject_get() is being called. WARNING: lib/kobject.c:642 at kobject_get lib/kobject.c:640 [inline], CPU#0: syz.0.0/5322 WARNING: lib/kobject.c:642 at kobject_add_internal+0xea/0xcd0 lib/kobject.c:225, CPU#0: syz.0.0/5322 Modules linked in: CPU: 0 UID: 0 PID: 5322 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:kobject_get lib/kobject.c:640 [inline] RIP: 0010:kobject_add_internal+0x113/0xcd0 lib/kobject.c:225 Code: 04 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 a7 f4 63 f6 49 8b 34 24 4c 89 f7 4c 89 e2 <67> 48 0f b9 3a e9 e4 00 00 00 e8 2e ac f2 f5 b8 fe ff ff ff e9 fb RSP: 0018:ffffc9000dd778a8 EFLAGS: 00010246 RAX: 1ffff11002423c1e RBX: ffff88804eb8a880 RCX: dffffc0000000000 RDX: ffff88801211e0f0 RSI: 0000000000000000 RDI: ffffffff908bede0 RBP: 0000000000000000 R08: ffff888000332580 R09: 0000000000000008 R10: 0000000000000007 R11: 0000000000000002 R12: ffff88801211e0f0 R13: dffffc0000000000 R14: ffffffff908bede0 R15: dffffc0000000000 FS: 00007f808bdd46c0(0000) GS:ffff88808c30a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562ec0c5c660 CR3: 0000000011f05000 CR4: 0000000000352ef0 Call Trace: kobject_add_varg lib/kobject.c:374 [inline] kobject_add+0x163/0x240 lib/kobject.c:426 bind_rdev_to_array+0x80c/0xdd0 drivers/md/md.c:2621 md_add_new_disk+0xe3b/0x1850 drivers/md/md.c:7684 md_ioctl+0x200a/0x2610 drivers/md/md.c:8499 blkdev_ioctl+0x5e3/0x740 block/ioctl.c:798 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f808f99e159 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:00007f808bdd3fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f808fc26180 RCX: 00007f808f99e159 RDX: 0000200000000420 RSI: 0000000040140921 RDI: 0000000000000007 RBP: 00007f808fa35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f808fc26218 R14: 00007f808fc26180 R15: 00007ffc655ce0d8 ---------------- Code disassembly (best guess): 0: 04 4c add $0x4c,%al 2: 89 e0 mov %esp,%eax 4: 48 c1 e8 03 shr $0x3,%rax 8: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx f: fc ff df 12: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) 16: 74 08 je 0x20 18: 4c 89 e7 mov %r12,%rdi 1b: e8 a7 f4 63 f6 call 0xf663f4c7 20: 49 8b 34 24 mov (%r12),%rsi 24: 4c 89 f7 mov %r14,%rdi 27: 4c 89 e2 mov %r12,%rdx * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: e9 e4 00 00 00 jmp 0x118 34: e8 2e ac f2 f5 call 0xf5f2ac67 39: b8 fe ff ff ff mov $0xfffffffe,%eax 3e: e9 .byte 0xe9 3f: fb sti