[syzbot] [erofs?] KMSAN: uninit-value in erofs_fc_fill_super

[syzbot <syzbot+1379ee6b9a14d5dacaf2@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    9b2ffa6148b1 Merge tag 'mtd/fixes-for-6.13-rc5' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=112374c4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f9048090d7bb0d06
dashboard link: https://syzkaller.appspot.com/bug?extid=1379ee6b9a14d5dacaf2
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/244f25c1a275/disk-9b2ffa61.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0d14fc6634fd/vmlinux-9b2ffa61.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cb152a4c0fd2/bzImage-9b2ffa61.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1379ee6b9a14d5dacaf2@syzkaller.appspotmail.com

exFAT-fs (loop7): failed to load upcase table (idx : 0x00010000, chksum : 0x1a9973fb, utbl_chksum : 0xe619d30d)
=====================================================
BUG: KMSAN: uninit-value in erofs_read_superblock fs/erofs/super.c:274 [inline]
BUG: KMSAN: uninit-value in erofs_fc_fill_super+0x66a/0x2520 fs/erofs/super.c:614
 erofs_read_superblock fs/erofs/super.c:274 [inline]
 erofs_fc_fill_super+0x66a/0x2520 fs/erofs/super.c:614
 vfs_get_super fs/super.c:1280 [inline]
 get_tree_nodev+0x183/0x350 fs/super.c:1299
 erofs_fc_get_tree+0x34d/0x450 fs/erofs/super.c:721
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3507
 path_mount+0x742/0x1f10 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x722/0x810 fs/namespace.c:4034
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4034
 x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 __alloc_pages_noprof+0x9a7/0xe00 mm/page_alloc.c:4776
 alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2269
 alloc_pages_noprof mm/mempolicy.c:2348 [inline]
 folio_alloc_noprof+0x1db/0x310 mm/mempolicy.c:2355
 filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1009
 __filemap_get_folio+0xac4/0x1550 mm/filemap.c:1951
 block_write_begin+0x6e/0x2b0 fs/buffer.c:2221
 exfat_write_begin+0xfb/0x400 fs/exfat/inode.c:434
 exfat_extend_valid_size fs/exfat/file.c:553 [inline]
 exfat_file_write_iter+0x771/0x12a0 fs/exfat/file.c:598
 do_iter_readv_writev+0x88a/0xa30
 vfs_writev+0x56a/0x14f0 fs/read_write.c:1050
 do_pwritev fs/read_write.c:1146 [inline]
 __do_sys_pwritev2 fs/read_write.c:1204 [inline]
 __se_sys_pwritev2+0x262/0x460 fs/read_write.c:1195
 __x64_sys_pwritev2+0x11f/0x1a0 fs/read_write.c:1195
 x64_sys_call+0x368c/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:329
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 8448 Comm: syz.7.643 Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================


---
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