==================================================================
BUG: KASAN: slab-out-of-bounds in dtInsertEntry+0x8a5/0x1270 fs/jfs/jfs_dtree.c:3999
Read of size 1 at addr ffff8880637e5fe0 by task syz.2.67/4655

CPU: 0 PID: 4655 Comm: syz.2.67 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 dtInsertEntry+0x8a5/0x1270 fs/jfs/jfs_dtree.c:3999
 dtSplitPage+0x2501/0x3200 fs/jfs/jfs_dtree.c:1596
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0xff4/0x5830 fs/jfs/jfs_dtree.c:871
 jfs_mkdir+0x758/0xad0 fs/jfs/namei.c:270
 vfs_mkdir+0x387/0x570 fs/namei.c:4073
 do_mkdirat+0x1df/0x5b0 fs/namei.c:4098
 __do_sys_mkdirat fs/namei.c:4113 [inline]
 __se_sys_mkdirat fs/namei.c:4111 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f70bf860687
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007f70bdabae58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f70bdabaee0 RCX: 00007f70bf860687
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000200000000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000003c0
R13: 00007f70bdabaea0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 4185:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 kmem_cache_zalloc include/linux/slab.h:728 [inline]
 __kernfs_new_node+0xe3/0x6c0 fs/kernfs/dir.c:593
 kernfs_new_node+0x148/0x250 fs/kernfs/dir.c:669
 __kernfs_create_file+0x47/0x2e0 fs/kernfs/file.c:985
 sysfs_add_file_mode_ns+0x2d4/0x3a0 fs/sysfs/file.c:317
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x495/0xd00 fs/sysfs/group.c:149
 internal_create_groups fs/sysfs/group.c:189 [inline]
 sysfs_create_groups+0x55/0x120 fs/sysfs/group.c:215
 device_add_groups drivers/base/core.c:2491 [inline]
 device_add_attrs+0x83/0x6a0 drivers/base/core.c:2639
 device_add+0x64b/0xfb0 drivers/base/core.c:3363
 rfkill_register+0x176/0x8a0 net/rfkill/core.c:1058
 hci_register_dev+0x452/0x970 net/bluetooth/hci_core.c:3964
 __vhci_create_device drivers/bluetooth/hci_vhci.c:129 [inline]
 vhci_create_device+0x32c/0x5c0 drivers/bluetooth/hci_vhci.c:153
 vhci_get_user drivers/bluetooth/hci_vhci.c:210 [inline]
 vhci_write+0x391/0x450 drivers/bluetooth/hci_vhci.c:290
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_write+0x152/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff8880637e5e80
 which belongs to the cache kernfs_node_cache of size 168
The buggy address is located 184 bytes to the right of
 168-byte region [ffff8880637e5e80, ffff8880637e5f28)
The buggy address belongs to the page:
page:ffffea00018df940 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x637e5
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888016de9b40
raw: 0000000000000000 0000000000110011 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 4185, ts 60690829823, free_ts 23074416193
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x195/0x290 mm/slub.c:3238
 kmem_cache_zalloc include/linux/slab.h:728 [inline]
 __kernfs_new_node+0xe3/0x6c0 fs/kernfs/dir.c:593
 kernfs_new_node+0x148/0x250 fs/kernfs/dir.c:669
 kernfs_create_dir_ns+0x40/0x120 fs/kernfs/dir.c:1005
 internal_create_group+0x21b/0xd00 fs/sysfs/group.c:137
 dpm_sysfs_add+0x66/0x270 drivers/base/power/sysfs.c:702
 device_add+0x715/0xfb0 drivers/base/core.c:3369
 hci_register_dev+0x3d0/0x970 net/bluetooth/hci_core.c:3954
 __vhci_create_device drivers/bluetooth/hci_vhci.c:129 [inline]
 vhci_create_device+0x32c/0x5c0 drivers/bluetooth/hci_vhci.c:153
 vhci_get_user drivers/bluetooth/hci_vhci.c:210 [inline]
 vhci_write+0x391/0x450 drivers/bluetooth/hci_vhci.c:290
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_write+0x152/0x260 fs/read_write.c:647
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 free_contig_range+0x96/0xf0 mm/page_alloc.c:9428
 destroy_args+0xf0/0xa00 mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x321/0x380 mm/debug_vm_pgtable.c:1336
 do_one_initcall+0x272/0x730 init/main.c:1316
 do_initcall_level+0x137/0x1f0 init/main.c:1389
 do_initcalls+0x4b/0x90 init/main.c:1405
 kernel_init_freeable+0x3e9/0x570 init/main.c:1629
 kernel_init+0x19/0x1b0 init/main.c:1520
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff8880637e5e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880637e5f00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
>ffff8880637e5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                       ^
 ffff8880637e6000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880637e6080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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