syzbot

loop0: detected capacity change from 0 to 1024
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BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x680/0x1270 fs/hfsplus/unicode.c:179
Read of size 2 at addr ffff88814ba5c40c by task syz-executor173/5831

CPU: 0 UID: 0 PID: 5831 Comm: syz-executor173 Not tainted 6.15.0-rc5-syzkaller-00275-gbec6f00f120e #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+0xb4/0x290 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+0x5af/0x770 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:403 [inline]
 __se_sys_getdents64+0xe4/0x260 fs/readdir.c:389
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cc23ff649
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 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:00007ffe991c7ee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007ffe991c80b8 RCX: 00007f6cc23ff649
RDX: 00000000000000bd RSI: 0000200000000900 RDI: 0000000000000003
RBP: 00007f6cc2473610 R08: 00000000000006e1 R09: 00007ffe991c80b8
R10: 00007ffe991c7da0 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe991c80a8 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Allocated by task 5831:
 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:4327 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339
 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+0x5af/0x770 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:403 [inline]
 __se_sys_getdents64+0xe4/0x260 fs/readdir.c:389
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88814ba5c000
 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 [ffff88814ba5c000, ffff88814ba5c40c)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14ba58
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 ffff88801a042000 ffffea00052e7c00 dead000000000002
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801a042000 ffffea00052e7c00 dead000000000002
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 057ff00000000003 ffffea00052e9601 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 18607178363, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718
 prep_new_page mm/page_alloc.c:1726 [inline]
 get_page_from_freelist+0x21ce/0x22b0 mm/page_alloc.c:3688
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2618
 new_slab mm/slub.c:2672 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
 __slab_alloc mm/slub.c:3948 [inline]
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kvmalloc_node_noprof+0x411/0x5e0 mm/slub.c:5012
 v4l2_ctrl_new+0xfb0/0x1780 drivers/media/v4l2-core/v4l2-ctrls-core.c:2067
 v4l2_ctrl_new_custom+0x57c/0x7b0 drivers/media/v4l2-core/v4l2-ctrls-core.c:2153
 vivid_create_controls+0xdd6/0x3a50 drivers/media/test-drivers/vivid/vivid-ctrls.c:1726
 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1933 [inline]
 vivid_probe+0x41bf/0x7180 drivers/media/test-drivers/vivid/vivid-core.c:2095
 platform_probe+0x148/0x1d0 drivers/base/platform.c:1404
 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
 driver_probe_device+0x4f/0x430 drivers/base/dd.c:829
 __driver_attach+0x452/0x700 drivers/base/dd.c:1215
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88814ba5c300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88814ba5c380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88814ba5c400: 00 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff88814ba5c480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88814ba5c500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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