WARNING in kernfs_remove_by_name_ns

Status: upstream: reported C repro on 2023/03/18 18:13
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+31f8f06b90e752e51bf8@syzkaller.appspotmail.com
First crash: 1227d, last: 441d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2023/05/19 upstream (ToT) 2d1bcbc6cd70 C [report] WARNING in kernfs_remove_by_name_ns
2026/07/02 upstream (ToT) 87320be9f0d2 C Failed due to an error; will retry later
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in kernfs_remove_by_name_ns -1 C error 6 306d 1081d 0/3 auto-obsoleted due to no activity on 2026/01/02 20:40
upstream WARNING in kernfs_remove_by_name_ns (2) kernfs -1 1 1897d 1893d 0/29 auto-closed as invalid on 2021/09/14 07:04
upstream WARNING in kernfs_remove_by_name_ns (3) kernfs -1 C error 629 47m 1722d 0/29 upstream: reported C repro on 2021/11/08 11:24
upstream WARNING in kernfs_remove_by_name_ns kernfs -1 4 2516d 2591d 0/29 auto-closed as invalid on 2020/01/04 08:56
▶ ▼ Fix bisection attempts (16)
Created Duration User Patch Repo Result
2025/02/27 09:09 13m bisect fix linux-6.1.y error job log
2025/01/26 12:36 2h05m bisect fix linux-6.1.y OK (0) job log log
2024/12/15 02:30 2h47m bisect fix linux-6.1.y OK (0) job log log
2024/10/31 02:29 3h01m bisect fix linux-6.1.y OK (0) job log log
2024/09/30 09:31 2h07m bisect fix linux-6.1.y OK (0) job log log
2024/08/21 12:35 2h08m bisect fix linux-6.1.y OK (0) job log log
2024/07/10 17:30 1h57m bisect fix linux-6.1.y OK (0) job log log
2024/06/01 11:47 2h07m bisect fix linux-6.1.y OK (0) job log log
2024/04/29 00:37 2h20m bisect fix linux-6.1.y OK (0) job log log
2024/03/28 22:57 2h40m bisect fix linux-6.1.y OK (0) job log log
2024/02/27 18:31 2h38m bisect fix linux-6.1.y OK (0) job log log
2024/01/18 19:09 2h42m bisect fix linux-6.1.y OK (0) job log log
2023/12/18 16:48 2h20m bisect fix linux-6.1.y OK (0) job log log
2023/10/17 19:43 1h15m bisect fix linux-6.1.y OK (0) job log log
2023/06/26 18:51 1h10m bisect fix linux-6.1.y OK (0) job log log
2023/05/25 14:14 57m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
------------[ cut here ]------------
kernfs: can not remove 'nr_tags', no directory
WARNING: CPU: 0 PID: 4296 at fs/kernfs/dir.c:1628 kernfs_remove_by_name_ns+0x10c/0x188
Modules linked in:
CPU: 0 PID: 4296 Comm: syz-executor398 Not tainted 6.1.62-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kernfs_remove_by_name_ns+0x10c/0x188
lr : kernfs_remove_by_name_ns+0x108/0x188 fs/kernfs/dir.c:1627
sp : ffff80001dd67750
x29: ffff80001dd67750 x28: 0000000000000008 x27: 1fffe00019cdb731
x26: 0000000000000002 x25: ffff800015ff9228 x24: 1ffff000024e91d8
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000000
x20: 00000000fffffffe x19: ffff800012748ec0 x18: ffff80001dd67020
x17: 0000000000000000 x16: ffff80001213551c x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000001
x11: ff808000081af79c x10: 0000000000000000 x9 : 28de01341650f700
x8 : 28de01341650f700 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff80001dd67038 x4 : ffff8000158f29c0 x3 : ffff80000858a904
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 kernfs_remove_by_name_ns+0x10c/0x188
 kernfs_remove_by_name include/linux/kernfs.h:622 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xf8/0x288 fs/sysfs/group.c:288
 sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:312
 __kobject_del+0x90/0x2d4 lib/kobject.c:587
 kobject_del+0x48/0x68 lib/kobject.c:619
 blk_mq_unregister_hctx block/blk-mq-sysfs.c:181 [inline]
 blk_mq_sysfs_unregister_hctxs+0x1c8/0x284 block/blk-mq-sysfs.c:309
 __blk_mq_update_nr_hw_queues block/blk-mq.c:4707 [inline]
 blk_mq_update_nr_hw_queues+0x524/0xf4c block/blk-mq.c:4753
 nbd_start_device+0x15c/0xa80 drivers/block/nbd.c:1361
 nbd_start_device_ioctl drivers/block/nbd.c:1411 [inline]
 __nbd_ioctl drivers/block/nbd.c:1487 [inline]
 nbd_ioctl+0x430/0xc40 drivers/block/nbd.c:1527
 blkdev_ioctl+0x408/0xb40 block/ioctl.c:617
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 1792
hardirqs last  enabled at (1791): [<ffff800008344a84>] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:261
hardirqs last disabled at (1792): [<ffff8000121311d4>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (132): [<ffff800008033064>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (130): [<ffff800008033030>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
kernfs: can not remove 'nr_reserved_tags', no directory
WARNING: CPU: 0 PID: 4296 at fs/kernfs/dir.c:1628 kernfs_remove_by_name_ns+0x10c/0x188
Modules linked in:
CPU: 0 PID: 4296 Comm: syz-executor398 Tainted: G        W          6.1.62-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kernfs_remove_by_name_ns+0x10c/0x188
lr : kernfs_remove_by_name_ns+0x108/0x188 fs/kernfs/dir.c:1627
sp : ffff80001dd67750
x29: ffff80001dd67750 x28: 0000000000000008 x27: 1fffe00019cdb731
x26: 0000000000000002 x25: ffff800015ff9230 x24: 1ffff000024e91d8
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000000
x20: 00000000fffffffe x19: ffff800012748ec0 x18: ffff80001dd67020
x17: 0000000000000000 x16: ffff8000083062e0 x15: 0000000000000000
x14: 1ffff00002b020b0 x13: dfff800000000000 x12: 0000000000000003
x11: ff8080000aad6a88 x10: 0000000000000003 x9 : 28de01341650f700
x8 : 28de01341650f700 x7 : ffff8000122007d4 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000006 x1 : ffff80001228c340 x0 : ffff80019ee02000
Call trace:
 kernfs_remove_by_name_ns+0x10c/0x188
 kernfs_remove_by_name include/linux/kernfs.h:622 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xf8/0x288 fs/sysfs/group.c:288
 sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:312
 __kobject_del+0x90/0x2d4 lib/kobject.c:587
 kobject_del+0x48/0x68 lib/kobject.c:619
 blk_mq_unregister_hctx block/blk-mq-sysfs.c:181 [inline]
 blk_mq_sysfs_unregister_hctxs+0x1c8/0x284 block/blk-mq-sysfs.c:309
 __blk_mq_update_nr_hw_queues block/blk-mq.c:4707 [inline]
 blk_mq_update_nr_hw_queues+0x524/0xf4c block/blk-mq.c:4753
 nbd_start_device+0x15c/0xa80 drivers/block/nbd.c:1361
 nbd_start_device_ioctl drivers/block/nbd.c:1411 [inline]
 __nbd_ioctl drivers/block/nbd.c:1487 [inline]
 nbd_ioctl+0x430/0xc40 drivers/block/nbd.c:1527
 blkdev_ioctl+0x408/0xb40 block/ioctl.c:617
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 1856
hardirqs last  enabled at (1855): [<ffff800012201508>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1366 [inline]
hardirqs last  enabled at (1855): [<ffff800012201508>] __schedule+0xff8/0x1c98 kernel/sched/core.c:6560
hardirqs last disabled at (1856): [<ffff8000121311d4>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (1838): [<ffff800008020d74>] softirq_handle_end kernel/softirq.c:414 [inline]
softirqs last  enabled at (1838): [<ffff800008020d74>] __do_softirq+0xc14/0xea0 kernel/softirq.c:600
softirqs last disabled at (1833): [<ffff80000802a99c>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
kernfs: can not remove 'cpu_list', no directory
WARNING: CPU: 0 PID: 4296 at fs/kernfs/dir.c:1628 kernfs_remove_by_name_ns+0x10c/0x188
Modules linked in:
CPU: 0 PID: 4296 Comm: syz-executor398 Tainted: G        W          6.1.62-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kernfs_remove_by_name_ns+0x10c/0x188
lr : kernfs_remove_by_name_ns+0x108/0x188 fs/kernfs/dir.c:1627
sp : ffff80001dd67750
x29: ffff80001dd67750 x28: 0000000000000008 x27: 1fffe00019cdb731
x26: 0000000000000002 x25: ffff800015ff9238 x24: 1ffff000024e91d8
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000000
x20: 00000000fffffffe x19: ffff800012748ec0 x18: 1fffe000368ac776
x17: ffff80001580d000 x16: ffff8000083062e0 x15: ffff0001b4563bbc
x14: 1ffff00002b020b0 x13: dfff800000000000 x12: 0000000000000001
x11: 1fffe0001b013850 x10: 0000000000000000 x9 : 28de01341650f700
x8 : 28de01341650f700 x7 : ffff80000827db78 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : ffff80000826b8dc
x2 : 0000000000000001 x1 : 0000000000000004 x0 : 0000000000000001
Call trace:
 kernfs_remove_by_name_ns+0x10c/0x188
 kernfs_remove_by_name include/linux/kernfs.h:622 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xf8/0x288 fs/sysfs/group.c:288
 sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:312
 __kobject_del+0x90/0x2d4 lib/kobject.c:587
 kobject_del+0x48/0x68 lib/kobject.c:619
 blk_mq_unregister_hctx block/blk-mq-sysfs.c:181 [inline]
 blk_mq_sysfs_unregister_hctxs+0x1c8/0x284 block/blk-mq-sysfs.c:309
 __blk_mq_update_nr_hw_queues block/blk-mq.c:4707 [inline]
 blk_mq_update_nr_hw_queues+0x524/0xf4c block/blk-mq.c:4753
 nbd_start_device+0x15c/0xa80 drivers/block/nbd.c:1361
 nbd_start_device_ioctl drivers/block/nbd.c:1411 [inline]
 __nbd_ioctl drivers/block/nbd.c:1487 [inline]
 nbd_ioctl+0x430/0xc40 drivers/block/nbd.c:1527
 blkdev_ioctl+0x408/0xb40 block/ioctl.c:617
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 1906
hardirqs last  enabled at (1905): [<ffff80000827dc18>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1366 [inline]
hardirqs last  enabled at (1905): [<ffff80000827dc18>] finish_lock_switch+0xbc/0x1e8 kernel/sched/core.c:5000
hardirqs last disabled at (1906): [<ffff8000121311d4>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (1876): [<ffff800008020d74>] softirq_handle_end kernel/softirq.c:414 [inline]
softirqs last  enabled at (1876): [<ffff800008020d74>] __do_softirq+0xc14/0xea0 kernel/softirq.c:600
softirqs last disabled at (1859): [<ffff80000802a99c>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79
---[ end trace 0000000000000000 ]---
block nbd0: shutting down sockets

Crashes (19):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/18 12:52 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/10/27 05:42 linux-6.1.y 32c9cdbe383c bf285f0c .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/03/18 18:30 linux-6.1.y 7eaef76fbc46 7939252e .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/07/15 13:43 linux-6.1.y 61fd484b2cf6 35d9ecc5 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2025/05/12 11:07 linux-6.1.y 02b72ccb5f9d 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2025/05/12 10:59 linux-6.1.y 02b72ccb5f9d 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2025/05/12 10:53 linux-6.1.y 02b72ccb5f9d 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2025/02/28 13:26 linux-6.1.y 3a8358583626 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/11/06 01:06 linux-6.1.y 4a61839152cc 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/10/27 05:25 linux-6.1.y 32c9cdbe383c bf285f0c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/09/14 06:03 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/09/05 18:45 linux-6.1.y c2cbfe5f5122 0b6286dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/08/27 10:36 linux-6.1.y cd363bb9548e 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/08/07 06:13 linux-6.1.y 52a953d0934b 4ffcc9ef .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/07/15 13:21 linux-6.1.y 61fd484b2cf6 35d9ecc5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/04/23 02:56 linux-6.1.y f17b0ab65d17 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/04/15 10:53 linux-6.1.y 0102425ac76b ec410564 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/04/07 19:33 linux-6.1.y 543aff194ab6 f7ba566d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
2023/03/18 18:13 linux-6.1.y 7eaef76fbc46 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kernfs_remove_by_name_ns
* Struck through repros no longer work on HEAD.