exFAT-fs (loop3): failed [   94.192599][ T4286] exFAT-fs (loop3): failed to load upcase table (idx : 0x00010000, chksum : 0xe3865569, utbl_chksum : 0xe619d30d)
==================================================================
BUG: KASAN: stack-out-of-bounds in exfat_nls_to_ucs2 fs/exfat/nls.c:619 [inline]
BUG: KASAN: stack-out-of-bounds in exfat_nls_to_utf16+0x899/0xa10 fs/exfat/nls.c:647
Read of size 1 at addr ffffc900034a7710 by task syz.3.17/4286

CPU: 0 UID: 0 PID: 4286 Comm: syz.3.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xf4/0x170 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
 exfat_nls_to_ucs2 fs/exfat/nls.c:619 [inline]
 exfat_nls_to_utf16+0x899/0xa10 fs/exfat/nls.c:647
 exfat_ioctl_set_volume_label fs/exfat/file.c:524 [inline]
 exfat_ioctl+0x2cc/0xde0 fs/exfat/file.c:554
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xb1/0x100 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8f/0x250 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f96226ceec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9622537038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9622925fa0 RCX: 00007f96226ceec9
RDX: 00002000000007c0 RSI: 0000000041009432 RDI: 0000000000000004
RBP: 00007f9622751f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9622926038 R14: 00007f9622925fa0 R15: 00007ffe95548628
 </TASK>

The buggy address belongs to stack of task syz.3.17/4286
 and is located at offset 304 in frame:
 exfat_ioctl+0x0/0xde0 fs/exfat/file.c:-1

This frame has 7 objects:
 [32, 36) 'lossy.i'
 [48, 304) 'label.i50'
 [368, 888) 'uniname.i51'
 [1024, 1280) 'label.i'
 [1344, 1864) 'uniname.i'
 [2000, 2024) 'range.i'
 [2064, 2144) 'ia.i'

The buggy address belongs to a 8-page vmalloc region starting at 0xffffc900034a0000 allocated at copy_process+0x3ab/0x2ff0 kernel/fork.c:2004
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888000000000 pfn:0x2a3ba
memcg:ffff88801a1ee402
flags: 0x80000000000000(node=0|zone=1)
raw: 0080000000000000 0000000000000000 dead000000000122 0000000000000000
raw: ffff888000000000 0000000000000000 00000001ffffffff ffff88801a1ee402
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), pid 40, tgid 40 (kworker/u8:2), ts 92756563485, free_ts 92748563255
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x168/0x1a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x27e0/0x2880 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x26b/0x460 mm/page_alloc.c:5148
 alloc_pages_mpol+0xcb/0x270 mm/mempolicy.c:2416
 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
 alloc_pages_noprof+0xe9/0x160 mm/mempolicy.c:2507
 vm_area_alloc_pages mm/vmalloc.c:3642 [inline]
 __vmalloc_area_node mm/vmalloc.c:3720 [inline]
 __vmalloc_node_range_noprof+0x6da/0xf50 mm/vmalloc.c:3893
 __vmalloc_node_noprof+0xc6/0xe0 mm/vmalloc.c:3956
 alloc_thread_stack_node kernel/fork.c:311 [inline]
 dup_task_struct+0x54e/0x6c0 kernel/fork.c:881
 copy_process+0x3ab/0x2ff0 kernel/fork.c:2004
 kernel_clone+0x195/0x640 kernel/fork.c:2605
 user_mode_thread+0xd8/0x130 kernel/fork.c:2683
 call_usermodehelper_exec_sync kernel/umh.c:132 [inline]
 call_usermodehelper_exec_work+0x79/0x1c0 kernel/umh.c:163
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x995/0x12d0 kernel/workqueue.c:3319
 worker_thread+0x850/0xc60 kernel/workqueue.c:3400
 kthread+0x598/0x690 kernel/kthread.c:463
 ret_from_fork+0x15e/0x2f0 arch/x86/kernel/process.c:148
page last free pid 21 tgid 21 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbf8/0xd90 mm/page_alloc.c:2895
 pagetable_free include/linux/mm.h:2898 [inline]
 pagetable_dtor_free include/linux/mm.h:2996 [inline]
 __tlb_remove_table+0x1c3/0x2a0 include/asm-generic/tlb.h:220
 __tlb_remove_table_free mm/mmu_gather.c:227 [inline]
 tlb_remove_table_rcu+0x6e/0xd0 mm/mmu_gather.c:290
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core kernel/rcu/tree.c:2861 [inline]
 rcu_cpu_kthread+0xa98/0x1800 kernel/rcu/tree.c:2949
 smpboot_thread_fn+0x3f7/0x7d0 kernel/smpboot.c:160
 kthread+0x598/0x690 kernel/kthread.c:463
 ret_from_fork+0x15e/0x2f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffffc900034a7600: 04 f2 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900034a7680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900034a7700: 00 00 f2 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00
                         ^
 ffffc900034a7780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900034a7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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