block/compat_ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/blkdev.h>
   3 #include <linux/blkpg.h>
   4 #include <linux/blktrace_api.h>
   5 #include <linux/cdrom.h>
   6 #include <linux/compat.h>
   7 #include <linux/elevator.h>
   8 #include <linux/hdreg.h>
   9 #include <linux/slab.h>
  10 #include <linux/syscalls.h>
  11 #include <linux/types.h>
  12 #include <linux/uaccess.h>
  13
  14 static int compat_put_ushort(unsigned long arg, unsigned short val)
  15 {
  16         return put_user(val, (unsigned short __user *)compat_ptr(arg));
  17 }
  18
  19 static int compat_put_int(unsigned long arg, int val)
  20 {
  21         return put_user(val, (compat_int_t __user *)compat_ptr(arg));
  22 }
  23
  24 static int compat_put_uint(unsigned long arg, unsigned int val)
  25 {
  26         return put_user(val, (compat_uint_t __user *)compat_ptr(arg));
  27 }
  28
  29 static int compat_put_long(unsigned long arg, long val)
  30 {
  31         return put_user(val, (compat_long_t __user *)compat_ptr(arg));
  32 }
  33
  34 static int compat_put_ulong(unsigned long arg, compat_ulong_t val)
  35 {
  36         return put_user(val, (compat_ulong_t __user *)compat_ptr(arg));
  37 }
  38
  39 static int compat_put_u64(unsigned long arg, u64 val)
  40 {
  41         return put_user(val, (compat_u64 __user *)compat_ptr(arg));
  42 }
  43
  44 struct compat_hd_geometry {
  45         unsigned char heads;
  46         unsigned char sectors;
  47         unsigned short cylinders;
  48         u32 start;
  49 };
  50
  51 static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev,
  52                         struct compat_hd_geometry __user *ugeo)
  53 {
  54         struct hd_geometry geo;
  55         int ret;
  56
  57         if (!ugeo)
  58                 return -EINVAL;
  59         if (!disk->fops->getgeo)
  60                 return -ENOTTY;
  61
  62         memset(&geo, 0, sizeof(geo));
  63         /*
  64          * We need to set the startsect first, the driver may
  65          * want to override it.
  66          */
  67         geo.start = get_start_sect(bdev);
  68         ret = disk->fops->getgeo(bdev, &geo);
  69         if (ret)
  70                 return ret;
  71
  72         ret = copy_to_user(ugeo, &geo, 4);
  73         ret |= put_user(geo.start, &ugeo->start);
  74         if (ret)
  75                 ret = -EFAULT;
  76
  77         return ret;
  78 }
  79
  80 static int compat_hdio_ioctl(struct block_device *bdev, fmode_t mode,
  81                 unsigned int cmd, unsigned long arg)
  82 {
  83         unsigned long __user *p;
  84         int error;
  85
  86         p = compat_alloc_user_space(sizeof(unsigned long));
  87         error = __blkdev_driver_ioctl(bdev, mode,
  88                                 cmd, (unsigned long)p);
  89         if (error == 0) {
  90                 unsigned int __user *uvp = compat_ptr(arg);
  91                 unsigned long v;
  92                 if (get_user(v, p) || put_user(v, uvp))
  93                         error = -EFAULT;
  94         }
  95         return error;
  96 }
  97
  98 struct compat_cdrom_read_audio {
  99         union cdrom_addr        addr;
 100         u8                      addr_format;
 101         compat_int_t            nframes;
 102         compat_caddr_t          buf;
 103 };
 104
 105 struct compat_cdrom_generic_command {
 106         unsigned char   cmd[CDROM_PACKET_SIZE];
 107         compat_caddr_t  buffer;
 108         compat_uint_t   buflen;
 109         compat_int_t    stat;
 110         compat_caddr_t  sense;
 111         unsigned char   data_direction;
 112         compat_int_t    quiet;
 113         compat_int_t    timeout;
 114         compat_caddr_t  reserved[1];
 115 };
 116
 117 static int compat_cdrom_read_audio(struct block_device *bdev, fmode_t mode,
 118                 unsigned int cmd, unsigned long arg)
 119 {
 120         struct cdrom_read_audio __user *cdread_audio;
 121         struct compat_cdrom_read_audio __user *cdread_audio32;
 122         __u32 data;
 123         void __user *datap;
 124
 125         cdread_audio = compat_alloc_user_space(sizeof(*cdread_audio));
 126         cdread_audio32 = compat_ptr(arg);
 127
 128         if (copy_in_user(&cdread_audio->addr,
 129                          &cdread_audio32->addr,
 130                          (sizeof(*cdread_audio32) -
 131                           sizeof(compat_caddr_t))))
 132                 return -EFAULT;
 133
 134         if (get_user(data, &cdread_audio32->buf))
 135                 return -EFAULT;
 136         datap = compat_ptr(data);
 137         if (put_user(datap, &cdread_audio->buf))
 138                 return -EFAULT;
 139
 140         return __blkdev_driver_ioctl(bdev, mode, cmd,
 141                         (unsigned long)cdread_audio);
 142 }
 143
 144 static int compat_cdrom_generic_command(struct block_device *bdev, fmode_t mode,
 145                 unsigned int cmd, unsigned long arg)
 146 {
 147         struct cdrom_generic_command __user *cgc;
 148         struct compat_cdrom_generic_command __user *cgc32;
 149         u32 data;
 150         unsigned char dir;
 151         int itmp;
 152
 153         cgc = compat_alloc_user_space(sizeof(*cgc));
 154         cgc32 = compat_ptr(arg);
 155
 156         if (copy_in_user(&cgc->cmd, &cgc32->cmd, sizeof(cgc->cmd)) ||
 157             get_user(data, &cgc32->buffer) ||
 158             put_user(compat_ptr(data), &cgc->buffer) ||
 159             copy_in_user(&cgc->buflen, &cgc32->buflen,
 160                          (sizeof(unsigned int) + sizeof(int))) ||
 161             get_user(data, &cgc32->sense) ||
 162             put_user(compat_ptr(data), &cgc->sense) ||
 163             get_user(dir, &cgc32->data_direction) ||
 164             put_user(dir, &cgc->data_direction) ||
 165             get_user(itmp, &cgc32->quiet) ||
 166             put_user(itmp, &cgc->quiet) ||
 167             get_user(itmp, &cgc32->timeout) ||
 168             put_user(itmp, &cgc->timeout) ||
 169             get_user(data, &cgc32->reserved[0]) ||
 170             put_user(compat_ptr(data), &cgc->reserved[0]))
 171                 return -EFAULT;
 172
 173         return __blkdev_driver_ioctl(bdev, mode, cmd, (unsigned long)cgc);
 174 }
 175
 176 struct compat_blkpg_ioctl_arg {
 177         compat_int_t op;
 178         compat_int_t flags;
 179         compat_int_t datalen;
 180         compat_caddr_t data;
 181 };
 182
 183 static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode,
 184                 unsigned int cmd, struct compat_blkpg_ioctl_arg __user *ua32)
 185 {
 186         struct blkpg_ioctl_arg __user *a = compat_alloc_user_space(sizeof(*a));
 187         compat_caddr_t udata;
 188         compat_int_t n;
 189         int err;
 190
 191         err = get_user(n, &ua32->op);
 192         err |= put_user(n, &a->op);
 193         err |= get_user(n, &ua32->flags);
 194         err |= put_user(n, &a->flags);
 195         err |= get_user(n, &ua32->datalen);
 196         err |= put_user(n, &a->datalen);
 197         err |= get_user(udata, &ua32->data);
 198         err |= put_user(compat_ptr(udata), &a->data);
 199         if (err)
 200                 return err;
 201
 202         return blkdev_ioctl(bdev, mode, cmd, (unsigned long)a);
 203 }
 204
 205 #define BLKBSZGET_32            _IOR(0x12, 112, int)
 206 #define BLKBSZSET_32            _IOW(0x12, 113, int)
 207 #define BLKGETSIZE64_32         _IOR(0x12, 114, int)
 208
 209 static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
 210                         unsigned cmd, unsigned long arg)
 211 {
 212         switch (cmd) {
 213         case HDIO_GET_UNMASKINTR:
 214         case HDIO_GET_MULTCOUNT:
 215         case HDIO_GET_KEEPSETTINGS:
 216         case HDIO_GET_32BIT:
 217         case HDIO_GET_NOWERR:
 218         case HDIO_GET_DMA:
 219         case HDIO_GET_NICE:
 220         case HDIO_GET_WCACHE:
 221         case HDIO_GET_ACOUSTIC:
 222         case HDIO_GET_ADDRESS:
 223         case HDIO_GET_BUSSTATE:
 224                 return compat_hdio_ioctl(bdev, mode, cmd, arg);
 225         case CDROMREADAUDIO:
 226                 return compat_cdrom_read_audio(bdev, mode, cmd, arg);
 227         case CDROM_SEND_PACKET:
 228                 return compat_cdrom_generic_command(bdev, mode, cmd, arg);
 229
 230         /*
 231          * No handler required for the ones below, we just need to
 232          * convert arg to a 64 bit pointer.
 233          */
 234         case BLKSECTSET:
 235         /*
 236          * 0x03 -- HD/IDE ioctl's used by hdparm and friends.
 237          *         Some need translations, these do not.
 238          */
 239         case HDIO_GET_IDENTITY:
 240         case HDIO_DRIVE_TASK:
 241         case HDIO_DRIVE_CMD:
 242         /* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */
 243         case 0x330:
 244         /* CDROM stuff */
 245         case CDROMPAUSE:
 246         case CDROMRESUME:
 247         case CDROMPLAYMSF:
 248         case CDROMPLAYTRKIND:
 249         case CDROMREADTOCHDR:
 250         case CDROMREADTOCENTRY:
 251         case CDROMSTOP:
 252         case CDROMSTART:
 253         case CDROMEJECT:
 254         case CDROMVOLCTRL:
 255         case CDROMSUBCHNL:
 256         case CDROMMULTISESSION:
 257         case CDROM_GET_MCN:
 258         case CDROMRESET:
 259         case CDROMVOLREAD:
 260         case CDROMSEEK:
 261         case CDROMPLAYBLK:
 262         case CDROMCLOSETRAY:
 263         case CDROM_DISC_STATUS:
 264         case CDROM_CHANGER_NSLOTS:
 265         case CDROM_GET_CAPABILITY:
 266         /* Ignore cdrom.h about these next 5 ioctls, they absolutely do
 267          * not take a struct cdrom_read, instead they take a struct cdrom_msf
 268          * which is compatible.
 269          */
 270         case CDROMREADMODE2:
 271         case CDROMREADMODE1:
 272         case CDROMREADRAW:
 273         case CDROMREADCOOKED:
 274         case CDROMREADALL:
 275         /* DVD ioctls */
 276         case DVD_READ_STRUCT:
 277         case DVD_WRITE_STRUCT:
 278         case DVD_AUTH:
 279                 arg = (unsigned long)compat_ptr(arg);
 280         /* These intepret arg as an unsigned long, not as a pointer,
 281          * so we must not do compat_ptr() conversion. */
 282         case HDIO_SET_MULTCOUNT:
 283         case HDIO_SET_UNMASKINTR:
 284         case HDIO_SET_KEEPSETTINGS:
 285         case HDIO_SET_32BIT:
 286         case HDIO_SET_NOWERR:
 287         case HDIO_SET_DMA:
 288         case HDIO_SET_PIO_MODE:
 289         case HDIO_SET_NICE:
 290         case HDIO_SET_WCACHE:
 291         case HDIO_SET_ACOUSTIC:
 292         case HDIO_SET_BUSSTATE:
 293         case HDIO_SET_ADDRESS:
 294         case CDROMEJECT_SW:
 295         case CDROM_SET_OPTIONS:
 296         case CDROM_CLEAR_OPTIONS:
 297         case CDROM_SELECT_SPEED:
 298         case CDROM_SELECT_DISC:
 299         case CDROM_MEDIA_CHANGED:
 300         case CDROM_DRIVE_STATUS:
 301         case CDROM_LOCKDOOR:
 302         case CDROM_DEBUG:
 303                 break;
 304         default:
 305                 /* unknown ioctl number */
 306                 return -ENOIOCTLCMD;
 307         }
 308
 309         return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 310 }
 311
 312 /* Most of the generic ioctls are handled in the normal fallback path.
 313    This assumes the blkdev's low level compat_ioctl always returns
 314    ENOIOCTLCMD for unknown ioctls. */
 315 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 316 {
 317         int ret = -ENOIOCTLCMD;
 318         struct inode *inode = file->f_mapping->host;
 319         struct block_device *bdev = inode->i_bdev;
 320         struct gendisk *disk = bdev->bd_disk;
 321         fmode_t mode = file->f_mode;
 322         loff_t size;
 323         unsigned int max_sectors;
 324
 325         /*
 326          * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
 327          * to updated it before every ioctl.
 328          */
 329         if (file->f_flags & O_NDELAY)
 330                 mode |= FMODE_NDELAY;
 331         else
 332                 mode &= ~FMODE_NDELAY;
 333
 334         switch (cmd) {
 335         case HDIO_GETGEO:
 336                 return compat_hdio_getgeo(disk, bdev, compat_ptr(arg));
 337         case BLKPBSZGET:
 338                 return compat_put_uint(arg, bdev_physical_block_size(bdev));
 339         case BLKIOMIN:
 340                 return compat_put_uint(arg, bdev_io_min(bdev));
 341         case BLKIOOPT:
 342                 return compat_put_uint(arg, bdev_io_opt(bdev));
 343         case BLKALIGNOFF:
 344                 return compat_put_int(arg, bdev_alignment_offset(bdev));
 345         case BLKDISCARDZEROES:
 346                 return compat_put_uint(arg, 0);
 347         case BLKFLSBUF:
 348         case BLKROSET:
 349         case BLKDISCARD:
 350         case BLKSECDISCARD:
 351         case BLKZEROOUT:
 352         /*
 353          * the ones below are implemented in blkdev_locked_ioctl,
 354          * but we call blkdev_ioctl, which gets the lock for us
 355          */
 356         case BLKRRPART:
 357                 return blkdev_ioctl(bdev, mode, cmd,
 358                                 (unsigned long)compat_ptr(arg));
 359         case BLKBSZSET_32:
 360                 return blkdev_ioctl(bdev, mode, BLKBSZSET,
 361                                 (unsigned long)compat_ptr(arg));
 362         case BLKPG:
 363                 return compat_blkpg_ioctl(bdev, mode, cmd, compat_ptr(arg));
 364         case BLKRAGET:
 365         case BLKFRAGET:
 366                 if (!arg)
 367                         return -EINVAL;
 368                 return compat_put_long(arg,
 369                                (bdev->bd_bdi->ra_pages * PAGE_SIZE) / 512);
 370         case BLKROGET: /* compatible */
 371                 return compat_put_int(arg, bdev_read_only(bdev) != 0);
 372         case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
 373                 return compat_put_int(arg, block_size(bdev));
 374         case BLKSSZGET: /* get block device hardware sector size */
 375                 return compat_put_int(arg, bdev_logical_block_size(bdev));
 376         case BLKSECTGET:
 377                 max_sectors = min_t(unsigned int, USHRT_MAX,
 378                                     queue_max_sectors(bdev_get_queue(bdev)));
 379                 return compat_put_ushort(arg, max_sectors);
 380         case BLKROTATIONAL:
 381                 return compat_put_ushort(arg,
 382                                          !blk_queue_nonrot(bdev_get_queue(bdev)));
 383         case BLKRASET: /* compatible, but no compat_ptr (!) */
 384         case BLKFRASET:
 385                 if (!capable(CAP_SYS_ADMIN))
 386                         return -EACCES;
 387                 bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
 388                 return 0;
 389         case BLKGETSIZE:
 390                 size = i_size_read(bdev->bd_inode);
 391                 if ((size >> 9) > ~0UL)
 392                         return -EFBIG;
 393                 return compat_put_ulong(arg, size >> 9);
 394
 395         case BLKGETSIZE64_32:
 396                 return compat_put_u64(arg, i_size_read(bdev->bd_inode));
 397
 398         case BLKTRACESETUP32:
 399         case BLKTRACESTART: /* compatible */
 400         case BLKTRACESTOP:  /* compatible */
 401         case BLKTRACETEARDOWN: /* compatible */
 402                 ret = blk_trace_ioctl(bdev, cmd, compat_ptr(arg));
 403                 return ret;
 404         default:
 405                 if (disk->fops->compat_ioctl)
 406                         ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
 407                 if (ret == -ENOIOCTLCMD)
 408                         ret = compat_blkdev_driver_ioctl(bdev, mode, cmd, arg);
 409                 return ret;
 410         }
 411 }