hfsplus: invalid length 65281 has been corrected to 255
==================================================================
BUG: KASAN: slab-out-of-bounds in hfsplus_strcasecmp+0x1bc/0x490 fs/hfsplus/unicode.c:47
Read of size 2 at addr ffff8880513b340c by task syz-executor/20727

CPU: 1 UID: 0 PID: 20727 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 hfsplus_strcasecmp+0x1bc/0x490 fs/hfsplus/unicode.c:47
 hfs_find_rec_by_key+0xa9/0x1e0 fs/hfsplus/bfind.c:89
 __hfsplus_brec_find+0x18e/0x480 fs/hfsplus/bfind.c:124
 hfsplus_brec_find+0x289/0x500 fs/hfsplus/bfind.c:184
 hfsplus_brec_read+0x2b/0x120 fs/hfsplus/bfind.c:211
 hfsplus_lookup+0x2aa/0x890 fs/hfsplus/dir.c:52
 __lookup_slow+0x297/0x3d0 fs/namei.c:1808
 lookup_slow+0x53/0x70 fs/namei.c:1825
 walk_component+0x2d2/0x400 fs/namei.c:2129
 lookup_last fs/namei.c:2630 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2654
 filename_lookup+0x212/0x570 fs/namei.c:2683
 user_path_at+0x3a/0x60 fs/namei.c:3127
 ksys_umount fs/namespace.c:2112 [inline]
 __do_sys_umount fs/namespace.c:2120 [inline]
 __se_sys_umount fs/namespace.c:2118 [inline]
 __x64_sys_umount+0xee/0x160 fs/namespace.c:2118
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe63d18ff17
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffdf0c143b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007fe63d211c05 RCX: 00007fe63d18ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdf0c14470
RBP: 00007ffdf0c14470 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdf0c15560
R13: 00007fe63d211c05 R14: 0000000000203a45 R15: 00007ffdf0c16630
 </TASK>

Allocated by task 20727:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4365 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:909 [inline]
 hfsplus_find_init+0x8c/0x1d0 fs/hfsplus/bfind.c:21
 hfsplus_lookup+0x19c/0x890 fs/hfsplus/dir.c:44
 __lookup_slow+0x297/0x3d0 fs/namei.c:1808
 lookup_slow+0x53/0x70 fs/namei.c:1825
 walk_component+0x2d2/0x400 fs/namei.c:2129
 lookup_last fs/namei.c:2630 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2654
 filename_lookup+0x212/0x570 fs/namei.c:2683
 user_path_at+0x3a/0x60 fs/namei.c:3127
 ksys_umount fs/namespace.c:2112 [inline]
 __do_sys_umount fs/namespace.c:2120 [inline]
 __se_sys_umount fs/namespace.c:2118 [inline]
 __x64_sys_umount+0xee/0x160 fs/namespace.c:2118
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880513b3000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 0 bytes to the right of
 allocated 1036-byte region [ffff8880513b3000, ffff8880513b340c)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x513b0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a442000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a442000 dead000000000100 dead000000000122
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea000144ec01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 15235, tgid 15235 (syz-executor), ts 801339859189, free_ts 801321803702
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab+0x8a/0x370 mm/slub.c:2655
 new_slab mm/slub.c:2709 [inline]
 ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891
 __slab_alloc mm/slub.c:3981 [inline]
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4391
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 psi_cgroup_alloc+0x56/0x200 kernel/sched/psi.c:1117
 cgroup_create kernel/cgroup/cgroup.c:5754 [inline]
 cgroup_mkdir+0x4a9/0xe60 kernel/cgroup/cgroup.c:5877
 kernfs_iop_mkdir+0x211/0x350 fs/kernfs/dir.c:1268
 vfs_mkdir+0x306/0x510 fs/namei.c:4366
 do_mkdirat+0x247/0x590 fs/namei.c:4399
 __do_sys_mkdirat fs/namei.c:4416 [inline]
 __se_sys_mkdirat fs/namei.c:4414 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4414
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 15235 tgid 15235 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 discard_slab mm/slub.c:2753 [inline]
 __put_partials+0x156/0x1a0 mm/slub.c:3218
 put_cpu_partial+0x17c/0x250 mm/slub.c:3293
 __slab_free+0x2d5/0x3c0 mm/slub.c:4550
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 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]
 __kmalloc_cache_noprof+0x1be/0x3d0 mm/slub.c:4391
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 find_css_set+0x9bb/0x1560 kernel/cgroup/cgroup.c:1214
 cgroup_migrate_prepare_dst+0x130/0x700 kernel/cgroup/cgroup.c:2854
 cgroup_attach_task+0x5ae/0x970 kernel/cgroup/cgroup.c:2958
 __cgroup_procs_write+0x2a7/0x300 kernel/cgroup/cgroup.c:5273
 cgroup_procs_write+0x27/0x50 kernel/cgroup/cgroup.c:5286
 cgroup_file_write+0x39e/0x740 kernel/cgroup/cgroup.c:4188
 kernfs_fop_write_iter+0x378/0x4f0 fs/kernfs/file.c:334
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686

Memory state around the buggy address:
 ffff8880513b3300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880513b3380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880513b3400: 00 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff8880513b3480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880513b3500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================