syzbot
WARNING: kobject bug in __scsi_remove_device
Status:
premoderation: reported syz repro on 2026/08/21 16:20
Reported-by: syzbot+b72d72498109e7c40dd4@syzkaller.appspotmail.com
First crash: 31d, last: 1d18h
Sample crash report:
------------[ cut here ]------------
kobject: '(null)' (ffff88811afb2548): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 0 PID: 431 at lib/kobject.c:736 kobject_put+0x8e/0x2a0 lib/kobject.c:734
Modules linked in:
CPU: 0 UID: 0 PID: 431 Comm: syz.6.22 Not tainted syzkaller #0 e67cc5743245539115c479145c763e2a95730d6f
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:kobject_put+0x8e/0x2a0 lib/kobject.c:734
Code: 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 34 41 44 fc 48 8b 33 48 c7 c7 40 16 9b 86 48 89 da e8 72 2d 68 fb <0f> 0b eb 0f e8 99 5d eb fb e9 9c 01 00 00 e8 8f 5d eb fb 4c 8d 7b
RSP: 0018:ffffc900007ef1f8 EFLAGS: 00010246
RAX: 1896363b774e8c00 RBX: ffff88811afb2548 RCX: ffff88810cbedf00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc900007ef220 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e9f334 R12: 00000000fffffff4
R13: ffff88811afb2584 R14: 1ffff110235f64b0 R15: 0000000000000000
FS: 000055555b85a500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbee65ed0e8 CR3: 000000011cae0000 CR4: 00000000003526b0
Call Trace:
<TASK>
put_device+0x23/0x40 drivers/base/core.c:3800
__scsi_remove_device+0xc4/0x3c0 drivers/scsi/scsi_sysfs.c:1501
scsi_alloc_sdev+0x970/0xcc0 drivers/scsi/scsi_scan.c:379
scsi_probe_and_add_lun+0x1e9/0x3e60 drivers/scsi/scsi_scan.c:1207
__scsi_scan_target+0x1f1/0xc20 drivers/scsi/scsi_scan.c:1754
scsi_scan_channel drivers/scsi/scsi_scan.c:1842 [inline]
scsi_scan_host_selected+0x352/0x610 drivers/scsi/scsi_scan.c:1871
scsi_scan drivers/scsi/scsi_sysfs.c:151 [inline]
store_scan+0x4ba/0x550 drivers/scsi/scsi_sysfs.c:191
dev_attr_store+0x76/0xa0 drivers/base/core.c:2440
sysfs_kf_write+0x13e/0x160 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x316/0x510 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:591 [inline]
vfs_write+0x75f/0xfd0 fs/read_write.c:684
ksys_write+0x145/0x260 fs/read_write.c:737
__do_sys_write fs/read_write.c:749 [inline]
__se_sys_write fs/read_write.c:746 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:746
x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2f3559e159
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:00007ffd16b74f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2f35825fa0 RCX: 00007f2f3559e159
RDX: 0000000000000005 RSI: 0000200000001400 RDI: 0000000000000003
RBP: 00007f2f3563506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f35825fac R14: 00007f2f35825fa0 R15: 00007f2f35825fa0
</TASK>
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 431 at lib/refcount.c:28 refcount_warn_saturate+0x119/0x1c0 lib/refcount.c:28
Modules linked in:
CPU: 1 UID: 0 PID: 431 Comm: syz.6.22 Tainted: G W syzkaller #0 e67cc5743245539115c479145c763e2a95730d6f
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:refcount_warn_saturate+0x119/0x1c0 lib/refcount.c:28
Code: 05 01 48 c7 c7 e0 f9 51 86 e8 e3 04 55 fe 0f 0b eb da e8 0a 35 d8 fe c6 05 19 1e 36 05 01 48 c7 c7 40 fa 51 86 e8 c7 04 55 fe <0f> 0b eb be e8 ee 34 d8 fe c6 05 fa 1d 36 05 01 48 c7 c7 80 f9 51
RSP: 0018:ffffc900007ef1d8 EFLAGS: 00010246
RAX: 1896363b774e8c00 RBX: 0000000000000003 RCX: ffff88810cbedf00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc900007ef1e8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e9f334 R12: 0000000000000000
R13: ffff88811afb2584 R14: ffff88811afb2580 R15: ffff88811afb2580
FS: 000055555b85a500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbee6270050 CR3: 000000011cae0000 CR4: 00000000003526b0
Call Trace:
<TASK>
__refcount_sub_and_test include/linux/refcount.h:400 [inline]
__refcount_dec_and_test include/linux/refcount.h:432 [inline]
refcount_dec_and_test include/linux/refcount.h:450 [inline]
kref_put include/linux/kref.h:64 [inline]
kobject_put+0x25a/0x2a0 lib/kobject.c:737
put_device+0x23/0x40 drivers/base/core.c:3800
__scsi_remove_device+0xc4/0x3c0 drivers/scsi/scsi_sysfs.c:1501
scsi_alloc_sdev+0x970/0xcc0 drivers/scsi/scsi_scan.c:379
scsi_probe_and_add_lun+0x1e9/0x3e60 drivers/scsi/scsi_scan.c:1207
__scsi_scan_target+0x1f1/0xc20 drivers/scsi/scsi_scan.c:1754
scsi_scan_channel drivers/scsi/scsi_scan.c:1842 [inline]
scsi_scan_host_selected+0x352/0x610 drivers/scsi/scsi_scan.c:1871
scsi_scan drivers/scsi/scsi_sysfs.c:151 [inline]
store_scan+0x4ba/0x550 drivers/scsi/scsi_sysfs.c:191
dev_attr_store+0x76/0xa0 drivers/base/core.c:2440
sysfs_kf_write+0x13e/0x160 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x316/0x510 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:591 [inline]
vfs_write+0x75f/0xfd0 fs/read_write.c:684
ksys_write+0x145/0x260 fs/read_write.c:737
__do_sys_write fs/read_write.c:749 [inline]
__se_sys_write fs/read_write.c:746 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:746
x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2f3559e159
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:00007ffd16b74f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2f35825fa0 RCX: 00007f2f3559e159
RDX: 0000000000000005 RSI: 0000200000001400 RDI: 0000000000000003
RBP: 00007f2f3563506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f35825fac R14: 00007f2f35825fa0 R15: 00007f2f35825fa0
</TASK>
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
kobject: '(null)' (ffff88811afb21d0): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 0 PID: 431 at lib/kobject.c:736 kobject_put+0x8e/0x2a0 lib/kobject.c:734
Modules linked in:
CPU: 0 UID: 0 PID: 431 Comm: syz.6.22 Tainted: G W syzkaller #0 e67cc5743245539115c479145c763e2a95730d6f
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:kobject_put+0x8e/0x2a0 lib/kobject.c:734
Code: 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 34 41 44 fc 48 8b 33 48 c7 c7 40 16 9b 86 48 89 da e8 72 2d 68 fb <0f> 0b eb 0f e8 99 5d eb fb e9 9c 01 00 00 e8 8f 5d eb fb 4c 8d 7b
RSP: 0018:ffffc900007ef1f8 EFLAGS: 00010246
RAX: 1896363b774e8c00 RBX: ffff88811afb21d0 RCX: ffff88810cbedf00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc900007ef220 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e9f334 R12: ffffffff86631910
R13: ffff88811afb220c R14: 1ffff110235f6441 R15: 0000000000000000
FS: 000055555b85a500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbee65ed0e8 CR3: 000000011cae0000 CR4: 00000000003526b0
Call Trace:
<TASK>
put_device+0x23/0x40 drivers/base/core.c:3800
__scsi_remove_device+0x32d/0x3c0 drivers/scsi/scsi_sysfs.c:1527
scsi_alloc_sdev+0x970/0xcc0 drivers/scsi/scsi_scan.c:379
scsi_probe_and_add_lun+0x1e9/0x3e60 drivers/scsi/scsi_scan.c:1207
__scsi_scan_target+0x1f1/0xc20 drivers/scsi/scsi_scan.c:1754
scsi_scan_channel drivers/scsi/scsi_scan.c:1842 [inline]
scsi_scan_host_selected+0x352/0x610 drivers/scsi/scsi_scan.c:1871
scsi_scan drivers/scsi/scsi_sysfs.c:151 [inline]
store_scan+0x4ba/0x550 drivers/scsi/scsi_sysfs.c:191
dev_attr_store+0x76/0xa0 drivers/base/core.c:2440
sysfs_kf_write+0x13e/0x160 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x316/0x510 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:591 [inline]
vfs_write+0x75f/0xfd0 fs/read_write.c:684
ksys_write+0x145/0x260 fs/read_write.c:737
__do_sys_write fs/read_write.c:749 [inline]
__se_sys_write fs/read_write.c:746 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:746
x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2f3559e159
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:00007ffd16b74f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2f35825fa0 RCX: 00007f2f3559e159
RDX: 0000000000000005 RSI: 0000200000001400 RDI: 0000000000000003
RBP: 00007f2f3563506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f35825fac R14: 00007f2f35825fa0 R15: 00007f2f35825fa0
</TASK>
---[ end trace 0000000000000000 ]---
scsi_alloc_sdev: Allocation failure during SCSI scanning, some SCSI devices might not be configured
------------[ cut here ]------------
kernel BUG at drivers/scsi/scsi_scan.c:594!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 431 Comm: syz.6.22 Tainted: G W syzkaller #0 e67cc5743245539115c479145c763e2a95730d6f
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:scsi_target_reap+0x172/0x180 drivers/scsi/scsi_scan.c:594
Code: 81 fe e9 ef fe ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 46 ff ff ff 4c 89 ef e8 78 51 81 fe e9 39 ff ff ff e8 1e 6e 28 fe <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 4a 27 18 8d 90 90 90
RSP: 0018:ffffc900007ef7a8 EFLAGS: 00010293
RAX: ffffffff835f0c52 RBX: ffff888116467800 RCX: ffff88810cbedf00
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005
RBP: ffffc900007ef7d0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520000fdee0 R12: ffff888116467800
R13: ffff888116467bc4 R14: 1ffff11022c8cf78 R15: 0000000000000005
FS: 000055555b85a500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbee6270050 CR3: 000000011cae0000 CR4: 00000000003526b0
Call Trace:
<TASK>
__scsi_scan_target+0x62c/0xc20 drivers/scsi/scsi_scan.c:1771
scsi_scan_channel drivers/scsi/scsi_scan.c:1842 [inline]
scsi_scan_host_selected+0x352/0x610 drivers/scsi/scsi_scan.c:1871
scsi_scan drivers/scsi/scsi_sysfs.c:151 [inline]
store_scan+0x4ba/0x550 drivers/scsi/scsi_sysfs.c:191
dev_attr_store+0x76/0xa0 drivers/base/core.c:2440
sysfs_kf_write+0x13e/0x160 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x316/0x510 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:591 [inline]
vfs_write+0x75f/0xfd0 fs/read_write.c:684
ksys_write+0x145/0x260 fs/read_write.c:737
__do_sys_write fs/read_write.c:749 [inline]
__se_sys_write fs/read_write.c:746 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:746
x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2f3559e159
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:00007ffd16b74f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2f35825fa0 RCX: 00007f2f3559e159
RDX: 0000000000000005 RSI: 0000200000001400 RDI: 0000000000000003
RBP: 00007f2f3563506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f35825fac R14: 00007f2f35825fa0 R15: 00007f2f35825fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:scsi_target_reap+0x172/0x180 drivers/scsi/scsi_scan.c:594
Code: 81 fe e9 ef fe ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 46 ff ff ff 4c 89 ef e8 78 51 81 fe e9 39 ff ff ff e8 1e 6e 28 fe <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 4a 27 18 8d 90 90 90
RSP: 0018:ffffc900007ef7a8 EFLAGS: 00010293
RAX: ffffffff835f0c52 RBX: ffff888116467800 RCX: ffff88810cbedf00
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005
RBP: ffffc900007ef7d0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520000fdee0 R12: ffff888116467800
R13: ffff888116467bc4 R14: 1ffff11022c8cf78 R15: 0000000000000005
FS: 000055555b85a500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbee6270050 CR3: 000000011cae0000 CR4: 00000000003526b0
* Struck through repros no longer work on HEAD.