==================================================================
BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x680/0x1270 fs/hfsplus/unicode.c:179
Read of size 2 at addr ffff888024e2840c by task syz-executor/6327

CPU: 1 UID: 0 PID: 6327 Comm: syz-executor Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 hfsplus_uni2asc+0x680/0x1270 fs/hfsplus/unicode.c:179
 hfsplus_readdir+0x709/0xd60 fs/hfsplus/dir.c:207
 iterate_dir+0x5ac/0x770 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64+0xe4/0x260 fs/readdir.c:396
 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: 0033:0x7fa938dc1293
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 72 3e f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8
RSP: 002b:00007fff2f0baa38 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 0000555581dbd600 RCX: 00007fa938dc1293
RDX: 0000000000008000 RSI: 0000555581dbd600 RDI: 0000000000000005
RBP: 0000555581dbd5d4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000293 R12: ffffffffffffffa8
R13: 0000000000000010 R14: 0000555581dbd5d0 R15: 00007fff2f0bccf0
 </TASK>

Allocated by task 6327:
 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:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4328 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4340
 kmalloc_noprof include/linux/slab.h:909 [inline]
 hfsplus_find_init+0x8c/0x1d0 fs/hfsplus/bfind.c:21
 hfsplus_readdir+0x1d4/0xd60 fs/hfsplus/dir.c:144
 iterate_dir+0x5ac/0x770 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64+0xe4/0x260 fs/readdir.c:396
 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 ffff888024e28000
 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 [ffff888024e28000, ffff888024e2840c)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24e28
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a442000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a442000 0000000000000000 dead000000000001
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000938a01 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 9186968829, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2619
 new_slab mm/slub.c:2673 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859
 __slab_alloc mm/slub.c:3949 [inline]
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4340
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 serdev_controller_alloc+0x39/0x240 drivers/tty/serdev/core.c:476
 serdev_tty_port_register+0x51/0x260 drivers/tty/serdev/serdev-ttyport.c:277
 tty_port_register_device_attr_serdev+0xe7/0x170 drivers/tty/tty_port.c:191
 serial_core_add_one_port drivers/tty/serial/serial_core.c:3181 [inline]
 serial_core_register_port+0x1063/0x2700 drivers/tty/serial/serial_core.c:3388
 serial8250_register_8250_port+0x16db/0x2050 drivers/tty/serial/8250/8250_core.c:822
 serial_pnp_probe+0x527/0x790 drivers/tty/serial/8250/8250_pnp.c:480
 pnp_device_probe+0x30b/0x4c0 drivers/pnp/driver.c:111
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26d/0x9a0 drivers/base/dd.c:657
 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888024e28300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888024e28380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888024e28400: 00 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff888024e28480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888024e28500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================