WARNING: kobject bug in __scsi_remove_device

Status: upstream: reported syz repro on 2026/08/17 20:44
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+fd064ac0ccd060dc7087@syzkaller.appspotmail.com
First crash: 12d, last: 1d21h
Bug presence (1)
Date Name Commit Repro Result
2026/08/19 upstream (ToT) 59e6295fac26 syz [report] INFO: task hung in scsi_scan_host_selected
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 WARNING: kobject bug in __scsi_remove_device -1 syz 7 7d23h 8d04h 0/1 premoderation: reported syz repro on 2026/08/21 16:20
linux-6.6 WARNING: kobject bug in __scsi_remove_device -1 syz 5 1d15h 10d 0/2 upstream: reported syz repro on 2026/08/19 13:20

Sample crash report:
kobject: '(null)' (ffff8880576846f8): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 1 PID: 4490 at lib/kobject.c:728 kobject_put+0x8c/0x450 lib/kobject.c:726
Modules linked in:
CPU: 1 PID: 4490 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:kobject_put+0x8c/0x450 lib/kobject.c:726
Code: 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 86 5f b7 f7 48 8b 33 48 c7 c7 60 92 b1 8b 48 89 da e8 04 bd 31 f7 <0f> 0b eb 05 e8 ab 32 66 f7 4c 8d 73 38 4c 89 f7 be 04 00 00 00 e8
RSP: 0000:ffffc900034975e0 EFLAGS: 00010246
RAX: b92c54394f9e4700 RBX: ffff8880576846f8 RCX: ffff888028bb8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffffffff90b1029f R09: 1ffffffff2162053
R10: dffffc0000000000 R11: fffffbfff2162054 R12: 1ffff1100aed08e6
R13: dffffc0000000000 R14: ffff888057684734 R15: 0000000000000200
FS:  000055558748a500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9d08d0f9c0 CR3: 0000000077cd1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __scsi_remove_device+0xc8/0x3b0 drivers/scsi/scsi_sysfs.c:1477
 scsi_alloc_sdev+0x91d/0xae0 drivers/scsi/scsi_scan.c:380
 scsi_probe_and_add_lun+0x1a0/0x44b0 drivers/scsi/scsi_scan.c:1183
 __scsi_scan_target+0x1d4/0x1050 drivers/scsi/scsi_scan.c:1715
 scsi_scan_channel drivers/scsi/scsi_scan.c:1803 [inline]
 scsi_scan_host_selected+0x374/0x6a0 drivers/scsi/scsi_scan.c:1832
 scsi_scan drivers/scsi/scsi_sysfs.c:151 [inline]
 store_scan+0x49c/0x530 drivers/scsi/scsi_sysfs.c:191
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f154819e0d9
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:00007ffd120887a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f1548425fa0 RCX: 00007f154819e0d9
RDX: 0000000000000006 RSI: 0000200000000500 RDI: 0000000000000003
RBP: 00007f1548235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1548425fac R14: 00007f1548425fa0 R15: 00007f1548425fa0
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/19 07:59 linux-6.1.y e4f7d8be268e 1e72964b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: kobject bug in __scsi_remove_device
2026/08/27 23:41 linux-6.1.y 79a9660d699e 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: kobject bug in __scsi_remove_device
2026/08/17 20:43 linux-6.1.y e4f7d8be268e 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: kobject bug in __scsi_remove_device
* Struck through repros no longer work on HEAD.