[snip]
> +static int exfat_verify_boot_region(struct super_block *sb) {
> +     struct buffer_head *bh = NULL;
> +     u32 chksum = 0, *p_sig, *p_chksum;
> +     int sn, i;
> +
> +     /* read boot sector sub-regions */
> +     for (sn = 0; sn < 11; sn++) {
> +             bh = sb_bread(sb, sn);
> +             if (!bh)
> +                     return -EIO;
> +
> +             if (sn != 0 && sn <= 8) {
> +                     /* extended boot sector sub-regions */
> +                     p_sig = (u32 *)&bh->b_data[sb->s_blocksize - 4];
> +                     if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE) {
> +                             exfat_err(sb, "no exboot-signature");
                                exfat_warn(sb, "Invalid exboot-signature(sector 
= %d): 0x%08x", sn, *p_sig);
> +                             brelse(bh);
> +                             return -EINVAL;
Don't make mount error, Just print warning message.
> +                     }
> +             }
> +
> +             chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
> +                     chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
> +             brelse(bh);
> +     }
> +
> +     /* boot checksum sub-regions */
> +     bh = sb_bread(sb, sn);
> +     if (!bh)
> +             return -EIO;
> +
> +     for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
> +             p_chksum = (u32 *)&bh->b_data[i];
> +             if (le32_to_cpu(*p_chksum) != chksum) {
> +                     exfat_err(sb, "mismatch checksum");
Print invalid checksum value also.
> +                     brelse(bh);
> +                     return -EINVAL;
> +             }
> +     }
> +     brelse(bh);
> +     return 0;
> +}
> +
>  /* mount the file system volume */
>  static int __exfat_fill_super(struct super_block *sb)  { @@ -498,6 +542,12 
> @@ static int
> __exfat_fill_super(struct super_block *sb)
>               goto free_bh;
>       }
> 
> +     ret = exfat_verify_boot_region(sb);
> +     if (ret) {
> +             exfat_err(sb, "invalid boot region");
> +             goto free_bh;
> +     }
> +
>       ret = exfat_create_upcase_table(sb);
>       if (ret) {
>               exfat_err(sb, "failed to load upcase table");
> --
> 2.25.1


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