==================================================================
BUG: KASAN: slab-use-after-free in sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:522
Read of size 8 at addr ffff888031db5230 by task syz.7.2000/17062

CPU: 0 UID: 0 PID: 17062 Comm: syz.7.2000 Not tainted 6.17.0-rc1-syzkaller-00016-g8742b2d8935f #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:522
 sysfs_remove_file include/linux/sysfs.h:777 [inline]
 driver_remove_file drivers/base/driver.c:201 [inline]
 driver_remove_file+0x4a/0x60 drivers/base/driver.c:197
 remove_bind_files drivers/base/bus.c:605 [inline]
 bus_remove_driver+0x224/0x2c0 drivers/base/bus.c:743
 driver_unregister+0x76/0xb0 drivers/base/driver.c:277
 comedi_device_detach_locked+0x12f/0xa50 drivers/comedi/drivers.c:207
 do_devconfig_ioctl+0x555/0x710 drivers/comedi/comedi_fops.c:848
 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2173
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl fs/ioctl.c:584 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a08b8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0a09a9c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0a08db6180 RCX: 00007f0a08b8ebe9
RDX: 0000000000000000 RSI: 0000000040946400 RDI: 0000000000000009
RBP: 00007f0a08c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a08db6218 R14: 00007f0a08db6180 R15: 00007ffeb6694a48
 </TASK>

Allocated by task 8376:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 bus_add_driver+0x92/0x690 drivers/base/bus.c:662
 driver_register+0x15c/0x4b0 drivers/base/driver.c:249
 c6xdigio_attach drivers/comedi/drivers/c6xdigio.c:253 [inline]
 c6xdigio_attach+0xa3/0x4b0 drivers/comedi/drivers/c6xdigio.c:238
 comedi_device_attach+0x3b3/0x900 drivers/comedi/drivers.c:1006
 do_devconfig_ioctl+0x1b1/0x710 drivers/comedi/comedi_fops.c:872
 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2173
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl fs/ioctl.c:584 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 15978:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free mm/slub.c:4680 [inline]
 kfree+0x2b4/0x4d0 mm/slub.c:4879
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e7/0x5a0 lib/kobject.c:737
 bus_remove_driver+0x16e/0x2c0 drivers/base/bus.c:749
 driver_unregister+0x76/0xb0 drivers/base/driver.c:277
 comedi_device_detach_locked+0x12f/0xa50 drivers/comedi/drivers.c:207
 do_devconfig_ioctl+0x555/0x710 drivers/comedi/comedi_fops.c:848
 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2173
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl fs/ioctl.c:584 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888031db5200
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 48 bytes inside of
 freed 256-byte region [ffff888031db5200, ffff888031db5300)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888031db4c00 pfn:0x31db4
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801b841b40 ffffea0000be2d10 ffffea0001ff9c10
raw: ffff888031db4c00 0000000000100009 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b841b40 ffffea0000be2d10 ffffea0001ff9c10
head: ffff888031db4c00 0000000000100009 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffea0000c76d01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5862, tgid 5862 (syz-executor), ts 115225134889, free_ts 115162269189
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab mm/slub.c:2655 [inline]
 new_slab+0x247/0x330 mm/slub.c:2709
 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 __do_kmalloc_node mm/slub.c:4364 [inline]
 __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 fib_create_info+0x53f/0x46b0 net/ipv4/fib_semantics.c:1402
 fib_table_insert+0x177/0x1c40 net/ipv4/fib_trie.c:1212
 fib_magic+0x4d4/0x5c0 net/ipv4/fib_frontend.c:1133
 fib_add_ifaddr+0x16d/0x580 net/ipv4/fib_frontend.c:1155
 fib_inetaddr_event+0x147/0x270 net/ipv4/fib_frontend.c:1469
 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
 blocking_notifier_call_chain kernel/notifier.c:380 [inline]
 blocking_notifier_call_chain+0x69/0xa0 kernel/notifier.c:368
 __inet_insert_ifa+0x925/0xcd0 net/ipv4/devinet.c:567
page last free pid 5997 tgid 5997 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
 discard_slab mm/slub.c:2753 [inline]
 __put_partials+0x165/0x1c0 mm/slub.c:3218
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4180 [inline]
 slab_alloc_node mm/slub.c:4229 [inline]
 kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4236
 vm_area_dup+0x27/0x8d0 mm/vma_init.c:122
 __split_vma+0x18e/0x1070 mm/vma.c:515
 split_vma mm/vma.c:598 [inline]
 vma_modify+0xee1/0x2030 mm/vma.c:1631
 vma_modify_flags+0x212/0x2d0 mm/vma.c:1649
 mprotect_fixup+0x1df/0xb40 mm/mprotect.c:819
 do_mprotect_pkey+0x9ca/0xd50 mm/mprotect.c:993
 __do_sys_mprotect mm/mprotect.c:1014 [inline]
 __se_sys_mprotect mm/mprotect.c:1011 [inline]
 __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:1011
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888031db5100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888031db5180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888031db5200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888031db5280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888031db5300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
------------[ cut here ]------------
kernfs: can not remove 'bind', no directory
WARNING: CPU: 0 PID: 17062 at fs/kernfs/dir.c:1706 kernfs_remove_by_name_ns+0xff/0x110 fs/kernfs/dir.c:1706
Modules linked in:
CPU: 0 UID: 0 PID: 17062 Comm: syz.7.2000 Tainted: G    B               6.17.0-rc1-syzkaller-00016-g8742b2d8935f #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:kernfs_remove_by_name_ns+0xff/0x110 fs/kernfs/dir.c:1706
Code: 48 89 df 31 db e8 61 a2 ff ff 48 89 ef e8 29 a5 36 ff eb b1 e8 22 32 5b ff 90 48 c7 c7 80 59 c3 8b 4c 89 e6 e8 62 d1 19 ff 90 <0f> 0b 90 90 eb b4 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc900033679c8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000de3b000
RDX: 0000000000080000 RSI: ffffffff817a3365 RDI: 0000000000000001
RBP: ffffffff8f503620 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 203a73666e72656b R12: ffffffff8c426c00
R13: 0000000000000000 R14: 0000000000000002 R15: ffff88807df60920
FS:  00007f0a09a9c6c0(0000) GS:ffff8881246c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e704ff8 CR3: 0000000063966000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 sysfs_remove_file include/linux/sysfs.h:777 [inline]
 driver_remove_file drivers/base/driver.c:201 [inline]
 driver_remove_file+0x4a/0x60 drivers/base/driver.c:197
 remove_bind_files drivers/base/bus.c:605 [inline]
 bus_remove_driver+0x224/0x2c0 drivers/base/bus.c:743
 driver_unregister+0x76/0xb0 drivers/base/driver.c:277
 comedi_device_detach_locked+0x12f/0xa50 drivers/comedi/drivers.c:207
 do_devconfig_ioctl+0x555/0x710 drivers/comedi/comedi_fops.c:848
 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2173
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl fs/ioctl.c:584 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a08b8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0a09a9c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0a08db6180 RCX: 00007f0a08b8ebe9
RDX: 0000000000000000 RSI: 0000000040946400 RDI: 0000000000000009
RBP: 00007f0a08c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a08db6218 R14: 00007f0a08db6180 R15: 00007ffeb6694a48
 </TASK>