syzbot

loop0: detected capacity change from 0 to 1024
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BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x588/0x1220 fs/hfsplus/unicode.c:179
Read of size 2 at addr ffff888144b4b40c by task syz-executor186/5838

CPU: 0 UID: 0 PID: 5838 Comm: syz-executor186 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 hfsplus_uni2asc+0x588/0x1220 fs/hfsplus/unicode.c:179
 hfsplus_readdir+0x94e/0x1350 fs/hfsplus/dir.c:207
 iterate_dir+0x5ab/0x760 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:403 [inline]
 __se_sys_getdents64+0x1e4/0x4c0 fs/readdir.c:389
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f83487e2ad9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe7c44e788 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f83487e2ad9
RDX: 00000000000000cb RSI: 0000200000000540 RDI: 0000000000000004
RBP: 00007f83488565f0 R08: 000055557ab264c0 R09: 000055557ab264c0
R10: 0000000000000673 R11: 0000000000000246 R12: 00007ffe7c44e7b0
R13: 00007ffe7c44e9d8 R14: 431bde82d7b634db R15: 00007f834882b03b
 </TASK>

Allocated by task 5838:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x9d/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4331 [inline]
 __kmalloc_noprof+0x28e/0x4d0 mm/slub.c:4343
 kmalloc_noprof include/linux/slab.h:909 [inline]
 hfsplus_find_init+0x87/0x1d0 fs/hfsplus/bfind.c:21
 hfsplus_readdir+0x211/0x1350 fs/hfsplus/dir.c:144
 iterate_dir+0x5ab/0x760 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:403 [inline]
 __se_sys_getdents64+0x1e4/0x4c0 fs/readdir.c:389
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888144b4b000
 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 [ffff888144b4b000, ffff888144b4b40c)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x144b48
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801b042000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801b042000 dead000000000100 dead000000000122
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 057ff00000000003 ffffea000512d201 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 1, tgid 1 (swapper/0), ts 10305054818, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1717
 prep_new_page mm/page_alloc.c:1725 [inline]
 get_page_from_freelist+0x352b/0x36c0 mm/page_alloc.c:3652
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2459 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2623
 new_slab mm/slub.c:2676 [inline]
 ___slab_alloc+0xc3b/0x1500 mm/slub.c:3862
 __slab_alloc+0x58/0xa0 mm/slub.c:3952
 __slab_alloc_node mm/slub.c:4027 [inline]
 slab_alloc_node mm/slub.c:4188 [inline]
 __kmalloc_cache_noprof+0x26a/0x370 mm/slub.c:4357
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 workqueue_sysfs_register+0x9a/0x3c0 kernel/workqueue.c:7393
 __alloc_workqueue+0x1804/0x1bc0 kernel/workqueue.c:5750
 alloc_workqueue+0xd8/0x210 kernel/workqueue.c:5786
 scsi_host_alloc+0xa2f/0xf20 drivers/scsi/hosts.c:520
 virtscsi_probe+0x250/0xf80 drivers/scsi/virtio_scsi.c:925
 virtio_dev_probe+0x933/0xc80 drivers/virtio/virtio.c:341
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x2bb/0xad0 drivers/base/dd.c:658
 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888144b4b300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888144b4b380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888144b4b400: 00 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff888144b4b480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888144b4b500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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