------------[ cut here ]------------ kernfs: can not remove 'nr_tags', no directory WARNING: CPU: 3 PID: 10520 at fs/kernfs/dir.c:1683 kernfs_remove_by_name_ns+0x110/0x130 fs/kernfs/dir.c:1683 Modules linked in: CPU: 3 PID: 10520 Comm: syz.2.1675 Not tainted 6.10.0-rc7-syzkaller-00256-gd0d0cd380055 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:kernfs_remove_by_name_ns+0x110/0x130 fs/kernfs/dir.c:1683 Code: 67 ff bb fe ff ff ff 89 d8 5b 5d 41 5c 41 5d c3 cc cc cc cc e8 21 f4 67 ff 90 48 c7 c7 20 1a 41 8b 4c 89 e6 e8 21 76 2a ff 90 <0f> 0b 90 90 eb cd e8 75 3a c5 ff e9 54 ff ff ff e8 6b 3a c5 ff e9 RSP: 0018:ffffc900041979f0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc900078e1000 RDX: 0000000000040000 RSI: ffffffff815112d6 RDI: 0000000000000001 RBP: ffffffff8e5f5240 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000003 R12: ffffffff8b8d9dc0 R13: 0000000000000000 R14: ffffffff8b8d9ce0 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff88802c300000(0063) knlGS:00000000f5d84b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00007f8fa035a440 CR3: 0000000065b00000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kernfs_remove_by_name include/linux/kernfs.h:625 [inline] remove_files+0x96/0x1c0 fs/sysfs/group.c:28 sysfs_remove_group+0x8b/0x180 fs/sysfs/group.c:319 sysfs_remove_groups fs/sysfs/group.c:343 [inline] sysfs_remove_groups+0x60/0xa0 fs/sysfs/group.c:335 __kobject_del+0x89/0x1f0 lib/kobject.c:595 kobject_del lib/kobject.c:627 [inline] kobject_del+0x3f/0x60 lib/kobject.c:619 blk_mq_unregister_hctx block/blk-mq-sysfs.c:155 [inline] blk_mq_unregister_hctx block/blk-mq-sysfs.c:144 [inline] blk_mq_sysfs_unregister_hctxs+0x258/0x2d0 block/blk-mq-sysfs.c:283 __blk_mq_update_nr_hw_queues block/blk-mq.c:4792 [inline] blk_mq_update_nr_hw_queues+0x8ab/0x1320 block/blk-mq.c:4838 nbd_start_device+0x15b/0xed0 drivers/block/nbd.c:1394 nbd_start_device_ioctl drivers/block/nbd.c:1445 [inline] __nbd_ioctl drivers/block/nbd.c:1520 [inline] nbd_ioctl+0x21a/0xfd0 drivers/block/nbd.c:1560 compat_blkdev_ioctl+0x30a/0x770 block/ioctl.c:732 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1007 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf746c579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f5d8457c EFLAGS: 00000292 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000000ab03 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi