hpfs: filesystem error: improperly stopped
hpfs: filesystem error: warning: spare dnodes used, try chkdsk
hpfs: You really don't want any checks? You are crazy...
hpfs: hpfs_map_sector(): read error
hpfs: code page support is disabled
hpfs: filesystem error: map_dirent: not a directory
hpfs: hpfs_map_4sectors(): unaligned read
hpfs: filesystem error: unable to find root dir
==================================================================
BUG: KASAN: slab-use-after-free in hpfs_bplus_lookup+0x4f4/0x880 fs/hpfs/anode.c:38
Read of size 4 at addr ffff8880399e6004 by task syz.0.18/6581

CPU: 0 UID: 0 PID: 6581 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 hpfs_bplus_lookup+0x4f4/0x880 fs/hpfs/anode.c:38
 hpfs_bmap+0x230/0x4e0 fs/hpfs/file.c:54
 hpfs_get_block+0xa8/0x6e0 fs/hpfs/file.c:87
 do_mpage_readpage+0x801/0x1980 fs/mpage.c:221
 mpage_readahead+0x407/0x830 fs/mpage.c:370
 read_pages+0x193/0x5a0 mm/readahead.c:163
 page_cache_ra_unbounded+0x706/0x980 mm/readahead.c:304
 do_page_cache_ra mm/readahead.c:334 [inline]
 page_cache_ra_order+0x2b5/0x490 mm/readahead.c:538
 filemap_get_pages+0x47c/0x1e70 mm/filemap.c:2696
 filemap_read+0x44a/0x1240 mm/filemap.c:2806
 __kernel_read+0x50d/0x9c0 fs/read_write.c:532
 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
 ima_calc_file_hash+0x452/0x870 security/integrity/ima/ima_crypto.c:280
 ima_collect_measurement+0x523/0x9d0 security/integrity/ima/ima_api.c:300
 process_measurement+0x12d9/0x1c90 security/integrity/ima/ima_main.c:425
 ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685
 security_file_post_open+0xb3/0x260 security/security.c:2755
 do_open fs/namei.c:4701 [inline]
 path_openat+0x2e88/0x38a0 fs/namei.c:4858
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcb18c3aef9
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:00007fcb1829e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fcb18ea5fa0 RCX: 00007fcb18c3aef9
RDX: 0000000000000000 RSI: 0000200000004280 RDI: ffffffffffffff9c
RBP: 00007fcb18ccfee0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcb18ea6038 R14: 00007fcb18ea5fa0 R15: 00007fff575723b8
 </TASK>

Allocated by task 6314:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4905
 __kernfs_new_node+0xea/0x980 fs/kernfs/dir.c:664
 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:748
 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057
 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x673/0x1180 fs/sysfs/group.c:189
 internal_create_groups fs/sysfs/group.c:229 [inline]
 sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:255
 device_add_groups drivers/base/core.c:2837 [inline]
 device_add_attrs+0x1bf/0x5b0 drivers/base/core.c:2912
 device_add+0x496/0xbb0 drivers/base/core.c:3645
 netdev_register_kobject+0x178/0x310 net/core/net-sysfs.c:2343
 register_netdevice+0x12d7/0x1d10 net/core/dev.c:11470
 register_netdev+0x40/0x60 net/core/dev.c:11586
 vti6_init_net+0x238/0x370 net/ipv6/ip6_vti.c:1158
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 setup_net+0x118/0x340 net/core/net_namespace.c:446
 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:579
 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234
 ksys_unshare+0x57d/0x9f0 kernel/fork.c:3245
 __do_sys_unshare kernel/fork.c:3319 [inline]
 __se_sys_unshare kernel/fork.c:3317 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3317
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 28:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kmem_cache_free+0x187/0x6c0 mm/slub.c:6373
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core kernel/rcu/tree.c:2869 [inline]
 rcu_cpu_kthread+0x99e/0x1470 kernel/rcu/tree.c:2957
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
 __call_rcu_common kernel/rcu/tree.c:3131 [inline]
 call_rcu+0xee/0x890 kernel/rcu/tree.c:3251
 kernfs_put+0x25c/0x520 fs/kernfs/dir.c:618
 kernfs_remove_by_name_ns+0xc8/0x140 fs/kernfs/dir.c:1799
 kernfs_remove_by_name include/linux/kernfs.h:639 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328
 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352
 device_remove_groups drivers/base/core.c:2844 [inline]
 device_remove_attrs+0x1cb/0x280 drivers/base/core.c:2974
 device_del+0x523/0x900 drivers/base/core.c:3894
 unregister_netdevice_many_notify+0x1d4b/0x22b0 net/core/dev.c:12499
 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
 ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248
 cleanup_net+0x56e/0x800 net/core/net_namespace.c:702
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880399e6000
 which belongs to the cache kernfs_node_cache of size 176
The buggy address is located 4 bytes inside of
 freed 176-byte region [ffff8880399e6000, ffff8880399e60b0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x399e6
flags: 0x80000000000000(node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000000 ffff88814040f000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800110011 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5902, tgid 5902 (syz-executor), ts 90163656525, free_ts 89837288931
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x27c8/0x2840 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x33c/0x3d0 mm/slub.c:7251
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 kmem_cache_alloc_noprof+0x433/0x680 mm/slub.c:4905
 __kernfs_new_node+0xea/0x980 fs/kernfs/dir.c:664
 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:748
 kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1121
 internal_create_group+0x425/0x1180 fs/sysfs/group.c:176
 internal_create_groups fs/sysfs/group.c:229 [inline]
 sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:255
 device_add_groups drivers/base/core.c:2837 [inline]
 device_add_attrs+0x1bf/0x5b0 drivers/base/core.c:2912
 device_add+0x496/0xbb0 drivers/base/core.c:3645
 netdev_register_kobject+0x178/0x310 net/core/net-sysfs.c:2343
 register_netdevice+0x12d7/0x1d10 net/core/dev.c:11470
page last free pid 36 tgid 36 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0xfa6/0x10f0 mm/page_alloc.c:2943
 kasan_depopulate_vmalloc_pte+0x6d/0x90 mm/kasan/shadow.c:484
 apply_to_pte_range mm/memory.c:3322 [inline]
 apply_to_pmd_range mm/memory.c:3366 [inline]
 apply_to_pud_range mm/memory.c:3402 [inline]
 apply_to_p4d_range mm/memory.c:3438 [inline]
 __apply_to_page_range+0xbdc/0x1420 mm/memory.c:3474
 __kasan_release_vmalloc+0xa2/0xd0 mm/kasan/shadow.c:602
 kasan_release_vmalloc include/linux/kasan.h:593 [inline]
 kasan_release_vmalloc_node mm/vmalloc.c:2284 [inline]
 purge_vmap_node+0x220/0x960 mm/vmalloc.c:2306
 __purge_vmap_area_lazy+0x779/0xb40 mm/vmalloc.c:2396
 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2430
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8880399e5f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880399e5f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880399e6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8880399e6080: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb
 ffff8880399e6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================