exFAT-fs (loop1): failed to load upcase table (idx : 0x00010000, chksum : 0x5441951d, utbl_chksum : 0xe619d30d)
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BUG: KASAN: stack-out-of-bounds in exfat_nls_to_ucs2+0x706/0x730 fs/exfat/nls.c:619
Read of size 1 at addr ffffc9000b047cc8 by task syz.1.27/6066

CPU: 0 UID: 0 PID: 6066 Comm: syz.1.27 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 exfat_nls_to_ucs2+0x706/0x730 fs/exfat/nls.c:619
 exfat_nls_to_utf16+0xa6/0xf0 fs/exfat/nls.c:647
 exfat_ioctl_set_volume_label+0x15d/0x230 fs/exfat/file.c:524
 exfat_ioctl+0x929/0x1630 fs/exfat/file.c:554
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f43dd78eec9
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:00007f43de597038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f43dd9e5fa0 RCX: 00007f43dd78eec9
RDX: 00002000000001c0 RSI: 0000000041009432 RDI: 0000000000000004
RBP: 00007f43dd811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f43dd9e6038 R14: 00007f43dd9e5fa0 R15: 00007ffe2ff38398
 </TASK>

The buggy address belongs to stack of task syz.1.27/6066
 and is located at offset 960 in frame:
 exfat_ioctl_set_volume_label+0x0/0x230 fs/exfat/file.c:507

This frame has 3 objects:
 [32, 36) 'lossy'
 [48, 568) 'uniname'
 [704, 960) 'label'

The buggy address belongs to a 8-page vmalloc region starting at 0xffffc9000b040000 allocated at kernel_clone+0xfc/0x930 kernel/fork.c:2609
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807d2f4110 pfn:0x7d2f4
memcg:ffff88801b779c82
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: ffff88807d2f4110 0000000000000000 00000001ffffffff ffff88801b779c82
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 6063, tgid 6063 (syz.1.27), ts 124637099960, free_ts 124314935208
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
 alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2507
 vm_area_alloc_pages mm/vmalloc.c:3647 [inline]
 __vmalloc_area_node mm/vmalloc.c:3724 [inline]
 __vmalloc_node_range_noprof+0x6f8/0x1480 mm/vmalloc.c:3897
 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:3960
 alloc_thread_stack_node kernel/fork.c:311 [inline]
 dup_task_struct kernel/fork.c:881 [inline]
 copy_process+0x2c77/0x76a0 kernel/fork.c:2012
 kernel_clone+0xfc/0x930 kernel/fork.c:2609
 __do_sys_clone3+0x212/0x290 kernel/fork.c:2911
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 6051 tgid 6048 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 tlb_batch_list_free mm/mmu_gather.c:159 [inline]
 tlb_finish_mmu+0x237/0x7c0 mm/mmu_gather.c:500
 exit_mmap+0x3fc/0xb90 mm/mmap.c:1293
 __mmput+0x12a/0x410 kernel/fork.c:1133
 mmput+0x62/0x70 kernel/fork.c:1156
 exit_mm kernel/exit.c:582 [inline]
 do_exit+0x7c7/0x2bf0 kernel/exit.c:954
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
 get_signal+0x2671/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffffc9000b047b80: f2 f2 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00
 ffffc9000b047c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000b047c80: 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 f3 f3
                                              ^
 ffffc9000b047d00: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000b047d80: 00 00 00 00 f1 f1 f1 f1 f1 f1 00 00 00 f2 f2 f2
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