fs/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ioctl.c
   4  *
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  */
   7
   8 #include <linux/syscalls.h>
   9 #include <linux/mm.h>
  10 #include <linux/capability.h>
  11 #include <linux/compat.h>
  12 #include <linux/file.h>
  13 #include <linux/fs.h>
  14 #include <linux/security.h>
  15 #include <linux/export.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/writeback.h>
  18 #include <linux/buffer_head.h>
  19 #include <linux/falloc.h>
  20 #include <linux/sched/signal.h>
  21 #include <linux/fiemap.h>
  22 #include <linux/mount.h>
  23 #include <linux/fscrypt.h>
  24 #include <linux/fileattr.h>
  25
  26 #include "internal.h"
  27
  28 #include <asm/ioctls.h>
  29
  30 /* So that the fiemap access checks can't overflow on 32 bit machines. */
  31 #define FIEMAP_MAX_EXTENTS      (UINT_MAX / sizeof(struct fiemap_extent))
  32
  33 /**
  34  * vfs_ioctl - call filesystem specific ioctl methods
  35  * @filp:       open file to invoke ioctl method on
  36  * @cmd:        ioctl command to execute
  37  * @arg:        command-specific argument for ioctl
  38  *
  39  * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
  40  * returns -ENOTTY.
  41  *
  42  * Returns 0 on success, -errno on error.
  43  */
  44 long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  45 {
  46         int error = -ENOTTY;
  47
  48         if (!filp->f_op->unlocked_ioctl)
  49                 goto out;
  50
  51         error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
  52         if (error == -ENOIOCTLCMD)
  53                 error = -ENOTTY;
  54  out:
  55         return error;
  56 }
  57 EXPORT_SYMBOL(vfs_ioctl);
  58
  59 static int ioctl_fibmap(struct file *filp, int __user *p)
  60 {
  61         struct inode *inode = file_inode(filp);
  62         struct super_block *sb = inode->i_sb;
  63         int error, ur_block;
  64         sector_t block;
  65
  66         if (!capable(CAP_SYS_RAWIO))
  67                 return -EPERM;
  68
  69         error = get_user(ur_block, p);
  70         if (error)
  71                 return error;
  72
  73         if (ur_block < 0)
  74                 return -EINVAL;
  75
  76         block = ur_block;
  77         error = bmap(inode, &block);
  78
  79         if (block > INT_MAX) {
  80                 error = -ERANGE;
  81                 pr_warn_ratelimited("[%s/%d] FS: %s File: %pD4 would truncate fibmap result\n",
  82                                     current->comm, task_pid_nr(current),
  83                                     sb->s_id, filp);
  84         }
  85
  86         if (error)
  87                 ur_block = 0;
  88         else
  89                 ur_block = block;
  90
  91         if (put_user(ur_block, p))
  92                 error = -EFAULT;
  93
  94         return error;
  95 }
  96
  97 /**
  98  * fiemap_fill_next_extent - Fiemap helper function
  99  * @fieinfo:    Fiemap context passed into ->fiemap
 100  * @logical:    Extent logical start offset, in bytes
 101  * @phys:       Extent physical start offset, in bytes
 102  * @len:        Extent length, in bytes
 103  * @flags:      FIEMAP_EXTENT flags that describe this extent
 104  *
 105  * Called from file system ->fiemap callback. Will populate extent
 106  * info as passed in via arguments and copy to user memory. On
 107  * success, extent count on fieinfo is incremented.
 108  *
 109  * Returns 0 on success, -errno on error, 1 if this was the last
 110  * extent that will fit in user array.
 111  */
 112 #define SET_UNKNOWN_FLAGS       (FIEMAP_EXTENT_DELALLOC)
 113 #define SET_NO_UNMOUNTED_IO_FLAGS       (FIEMAP_EXTENT_DATA_ENCRYPTED)
 114 #define SET_NOT_ALIGNED_FLAGS   (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
 115 int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
 116                             u64 phys, u64 len, u32 flags)
 117 {
 118         struct fiemap_extent extent;
 119         struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
 120
 121         /* only count the extents */
 122         if (fieinfo->fi_extents_max == 0) {
 123                 fieinfo->fi_extents_mapped++;
 124                 return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 125         }
 126
 127         if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
 128                 return 1;
 129
 130         if (flags & SET_UNKNOWN_FLAGS)
 131                 flags |= FIEMAP_EXTENT_UNKNOWN;
 132         if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
 133                 flags |= FIEMAP_EXTENT_ENCODED;
 134         if (flags & SET_NOT_ALIGNED_FLAGS)
 135                 flags |= FIEMAP_EXTENT_NOT_ALIGNED;
 136
 137         memset(&extent, 0, sizeof(extent));
 138         extent.fe_logical = logical;
 139         extent.fe_physical = phys;
 140         extent.fe_length = len;
 141         extent.fe_flags = flags;
 142
 143         dest += fieinfo->fi_extents_mapped;
 144         if (copy_to_user(dest, &extent, sizeof(extent)))
 145                 return -EFAULT;
 146
 147         fieinfo->fi_extents_mapped++;
 148         if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
 149                 return 1;
 150         return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 151 }
 152 EXPORT_SYMBOL(fiemap_fill_next_extent);
 153
 154 /**
 155  * fiemap_prep - check validity of requested flags for fiemap
 156  * @inode:      Inode to operate on
 157  * @fieinfo:    Fiemap context passed into ->fiemap
 158  * @start:      Start of the mapped range
 159  * @len:        Length of the mapped range, can be truncated by this function.
 160  * @supported_flags:    Set of fiemap flags that the file system understands
 161  *
 162  * This function must be called from each ->fiemap instance to validate the
 163  * fiemap request against the file system parameters.
 164  *
 165  * Returns 0 on success, or a negative error on failure.
 166  */
 167 int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo,
 168                 u64 start, u64 *len, u32 supported_flags)
 169 {
 170         u64 maxbytes = inode->i_sb->s_maxbytes;
 171         u32 incompat_flags;
 172         int ret = 0;
 173
 174         if (*len == 0)
 175                 return -EINVAL;
 176         if (start > maxbytes)
 177                 return -EFBIG;
 178
 179         /*
 180          * Shrink request scope to what the fs can actually handle.
 181          */
 182         if (*len > maxbytes || (maxbytes - *len) < start)
 183                 *len = maxbytes - start;
 184
 185         supported_flags |= FIEMAP_FLAG_SYNC;
 186         supported_flags &= FIEMAP_FLAGS_COMPAT;
 187         incompat_flags = fieinfo->fi_flags & ~supported_flags;
 188         if (incompat_flags) {
 189                 fieinfo->fi_flags = incompat_flags;
 190                 return -EBADR;
 191         }
 192
 193         if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
 194                 ret = filemap_write_and_wait(inode->i_mapping);
 195         return ret;
 196 }
 197 EXPORT_SYMBOL(fiemap_prep);
 198
 199 static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
 200 {
 201         struct fiemap fiemap;
 202         struct fiemap_extent_info fieinfo = { 0, };
 203         struct inode *inode = file_inode(filp);
 204         int error;
 205
 206         if (!inode->i_op->fiemap)
 207                 return -EOPNOTSUPP;
 208
 209         if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
 210                 return -EFAULT;
 211
 212         if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
 213                 return -EINVAL;
 214
 215         fieinfo.fi_flags = fiemap.fm_flags;
 216         fieinfo.fi_extents_max = fiemap.fm_extent_count;
 217         fieinfo.fi_extents_start = ufiemap->fm_extents;
 218
 219         error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
 220                         fiemap.fm_length);
 221
 222         fiemap.fm_flags = fieinfo.fi_flags;
 223         fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
 224         if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
 225                 error = -EFAULT;
 226
 227         return error;
 228 }
 229
 230 static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
 231                              u64 off, u64 olen, u64 destoff)
 232 {
 233         struct fd src_file = fdget(srcfd);
 234         loff_t cloned;
 235         int ret;
 236
 237         if (!src_file.file)
 238                 return -EBADF;
 239         ret = -EXDEV;
 240         if (src_file.file->f_path.mnt != dst_file->f_path.mnt)
 241                 goto fdput;
 242         cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
 243                                       olen, 0);
 244         if (cloned < 0)
 245                 ret = cloned;
 246         else if (olen && cloned != olen)
 247                 ret = -EINVAL;
 248         else
 249                 ret = 0;
 250 fdput:
 251         fdput(src_file);
 252         return ret;
 253 }
 254
 255 static long ioctl_file_clone_range(struct file *file,
 256                                    struct file_clone_range __user *argp)
 257 {
 258         struct file_clone_range args;
 259
 260         if (copy_from_user(&args, argp, sizeof(args)))
 261                 return -EFAULT;
 262         return ioctl_file_clone(file, args.src_fd, args.src_offset,
 263                                 args.src_length, args.dest_offset);
 264 }
 265
 266 /*
 267  * This provides compatibility with legacy XFS pre-allocation ioctls
 268  * which predate the fallocate syscall.
 269  *
 270  * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
 271  * are used here, rest are ignored.
 272  */
 273 static int ioctl_preallocate(struct file *filp, int mode, void __user *argp)
 274 {
 275         struct inode *inode = file_inode(filp);
 276         struct space_resv sr;
 277
 278         if (copy_from_user(&sr, argp, sizeof(sr)))
 279                 return -EFAULT;
 280
 281         switch (sr.l_whence) {
 282         case SEEK_SET:
 283                 break;
 284         case SEEK_CUR:
 285                 sr.l_start += filp->f_pos;
 286                 break;
 287         case SEEK_END:
 288                 sr.l_start += i_size_read(inode);
 289                 break;
 290         default:
 291                 return -EINVAL;
 292         }
 293
 294         return vfs_fallocate(filp, mode | FALLOC_FL_KEEP_SIZE, sr.l_start,
 295                         sr.l_len);
 296 }
 297
 298 /* on ia32 l_start is on a 32-bit boundary */
 299 #if defined CONFIG_COMPAT && defined(CONFIG_X86_64)
 300 /* just account for different alignment */
 301 static int compat_ioctl_preallocate(struct file *file, int mode,
 302                                     struct space_resv_32 __user *argp)
 303 {
 304         struct inode *inode = file_inode(file);
 305         struct space_resv_32 sr;
 306
 307         if (copy_from_user(&sr, argp, sizeof(sr)))
 308                 return -EFAULT;
 309
 310         switch (sr.l_whence) {
 311         case SEEK_SET:
 312                 break;
 313         case SEEK_CUR:
 314                 sr.l_start += file->f_pos;
 315                 break;
 316         case SEEK_END:
 317                 sr.l_start += i_size_read(inode);
 318                 break;
 319         default:
 320                 return -EINVAL;
 321         }
 322
 323         return vfs_fallocate(file, mode | FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
 324 }
 325 #endif
 326
 327 static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p)
 328 {
 329         switch (cmd) {
 330         case FIBMAP:
 331                 return ioctl_fibmap(filp, p);
 332         case FS_IOC_RESVSP:
 333         case FS_IOC_RESVSP64:
 334                 return ioctl_preallocate(filp, 0, p);
 335         case FS_IOC_UNRESVSP:
 336         case FS_IOC_UNRESVSP64:
 337                 return ioctl_preallocate(filp, FALLOC_FL_PUNCH_HOLE, p);
 338         case FS_IOC_ZERO_RANGE:
 339                 return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p);
 340         }
 341
 342         return -ENOIOCTLCMD;
 343 }
 344
 345 static int ioctl_fionbio(struct file *filp, int __user *argp)
 346 {
 347         unsigned int flag;
 348         int on, error;
 349
 350         error = get_user(on, argp);
 351         if (error)
 352                 return error;
 353         flag = O_NONBLOCK;
 354 #ifdef __sparc__
 355         /* SunOS compatibility item. */
 356         if (O_NONBLOCK != O_NDELAY)
 357                 flag |= O_NDELAY;
 358 #endif
 359         spin_lock(&filp->f_lock);
 360         if (on)
 361                 filp->f_flags |= flag;
 362         else
 363                 filp->f_flags &= ~flag;
 364         spin_unlock(&filp->f_lock);
 365         return error;
 366 }
 367
 368 static int ioctl_fioasync(unsigned int fd, struct file *filp,
 369                           int __user *argp)
 370 {
 371         unsigned int flag;
 372         int on, error;
 373
 374         error = get_user(on, argp);
 375         if (error)
 376                 return error;
 377         flag = on ? FASYNC : 0;
 378
 379         /* Did FASYNC state change ? */
 380         if ((flag ^ filp->f_flags) & FASYNC) {
 381                 if (filp->f_op->fasync)
 382                         /* fasync() adjusts filp->f_flags */
 383                         error = filp->f_op->fasync(fd, filp, on);
 384                 else
 385                         error = -ENOTTY;
 386         }
 387         return error < 0 ? error : 0;
 388 }
 389
 390 static int ioctl_fsfreeze(struct file *filp)
 391 {
 392         struct super_block *sb = file_inode(filp)->i_sb;
 393
 394         if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 395                 return -EPERM;
 396
 397         /* If filesystem doesn't support freeze feature, return. */
 398         if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
 399                 return -EOPNOTSUPP;
 400
 401         /* Freeze */
 402         if (sb->s_op->freeze_super)
 403                 return sb->s_op->freeze_super(sb);
 404         return freeze_super(sb);
 405 }
 406
 407 static int ioctl_fsthaw(struct file *filp)
 408 {
 409         struct super_block *sb = file_inode(filp)->i_sb;
 410
 411         if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 412                 return -EPERM;
 413
 414         /* Thaw */
 415         if (sb->s_op->thaw_super)
 416                 return sb->s_op->thaw_super(sb);
 417         return thaw_super(sb);
 418 }
 419
 420 static int ioctl_file_dedupe_range(struct file *file,
 421                                    struct file_dedupe_range __user *argp)
 422 {
 423         struct file_dedupe_range *same = NULL;
 424         int ret;
 425         unsigned long size;
 426         u16 count;
 427
 428         if (get_user(count, &argp->dest_count)) {
 429                 ret = -EFAULT;
 430                 goto out;
 431         }
 432
 433         size = offsetof(struct file_dedupe_range __user, info[count]);
 434         if (size > PAGE_SIZE) {
 435                 ret = -ENOMEM;
 436                 goto out;
 437         }
 438
 439         same = memdup_user(argp, size);
 440         if (IS_ERR(same)) {
 441                 ret = PTR_ERR(same);
 442                 same = NULL;
 443                 goto out;
 444         }
 445
 446         same->dest_count = count;
 447         ret = vfs_dedupe_file_range(file, same);
 448         if (ret)
 449                 goto out;
 450
 451         ret = copy_to_user(argp, same, size);
 452         if (ret)
 453                 ret = -EFAULT;
 454
 455 out:
 456         kfree(same);
 457         return ret;
 458 }
 459
 460 /**
 461  * fileattr_fill_xflags - initialize fileattr with xflags
 462  * @fa:         fileattr pointer
 463  * @xflags:     FS_XFLAG_* flags
 464  *
 465  * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags).  All
 466  * other fields are zeroed.
 467  */
 468 void fileattr_fill_xflags(struct fileattr *fa, u32 xflags)
 469 {
 470         memset(fa, 0, sizeof(*fa));
 471         fa->fsx_valid = true;
 472         fa->fsx_xflags = xflags;
 473         if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE)
 474                 fa->flags |= FS_IMMUTABLE_FL;
 475         if (fa->fsx_xflags & FS_XFLAG_APPEND)
 476                 fa->flags |= FS_APPEND_FL;
 477         if (fa->fsx_xflags & FS_XFLAG_SYNC)
 478                 fa->flags |= FS_SYNC_FL;
 479         if (fa->fsx_xflags & FS_XFLAG_NOATIME)
 480                 fa->flags |= FS_NOATIME_FL;
 481         if (fa->fsx_xflags & FS_XFLAG_NODUMP)
 482                 fa->flags |= FS_NODUMP_FL;
 483         if (fa->fsx_xflags & FS_XFLAG_DAX)
 484                 fa->flags |= FS_DAX_FL;
 485         if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
 486                 fa->flags |= FS_PROJINHERIT_FL;
 487 }
 488 EXPORT_SYMBOL(fileattr_fill_xflags);
 489
 490 /**
 491  * fileattr_fill_flags - initialize fileattr with flags
 492  * @fa:         fileattr pointer
 493  * @flags:      FS_*_FL flags
 494  *
 495  * Set ->flags, ->flags_valid and ->fsx_xflags (translated flags).
 496  * All other fields are zeroed.
 497  */
 498 void fileattr_fill_flags(struct fileattr *fa, u32 flags)
 499 {
 500         memset(fa, 0, sizeof(*fa));
 501         fa->flags_valid = true;
 502         fa->flags = flags;
 503         if (fa->flags & FS_SYNC_FL)
 504                 fa->fsx_xflags |= FS_XFLAG_SYNC;
 505         if (fa->flags & FS_IMMUTABLE_FL)
 506                 fa->fsx_xflags |= FS_XFLAG_IMMUTABLE;
 507         if (fa->flags & FS_APPEND_FL)
 508                 fa->fsx_xflags |= FS_XFLAG_APPEND;
 509         if (fa->flags & FS_NODUMP_FL)
 510                 fa->fsx_xflags |= FS_XFLAG_NODUMP;
 511         if (fa->flags & FS_NOATIME_FL)
 512                 fa->fsx_xflags |= FS_XFLAG_NOATIME;
 513         if (fa->flags & FS_DAX_FL)
 514                 fa->fsx_xflags |= FS_XFLAG_DAX;
 515         if (fa->flags & FS_PROJINHERIT_FL)
 516                 fa->fsx_xflags |= FS_XFLAG_PROJINHERIT;
 517 }
 518 EXPORT_SYMBOL(fileattr_fill_flags);
 519
 520 /**
 521  * vfs_fileattr_get - retrieve miscellaneous file attributes
 522  * @dentry:     the object to retrieve from
 523  * @fa:         fileattr pointer
 524  *
 525  * Call i_op->fileattr_get() callback, if exists.
 526  *
 527  * Return: 0 on success, or a negative error on failure.
 528  */
 529 int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 530 {
 531         struct inode *inode = d_inode(dentry);
 532
 533         if (!inode->i_op->fileattr_get)
 534                 return -ENOIOCTLCMD;
 535
 536         return inode->i_op->fileattr_get(dentry, fa);
 537 }
 538 EXPORT_SYMBOL(vfs_fileattr_get);
 539
 540 /**
 541  * copy_fsxattr_to_user - copy fsxattr to userspace.
 542  * @fa:         fileattr pointer
 543  * @ufa:        fsxattr user pointer
 544  *
 545  * Return: 0 on success, or -EFAULT on failure.
 546  */
 547 int copy_fsxattr_to_user(const struct fileattr *fa, struct fsxattr __user *ufa)
 548 {
 549         struct fsxattr xfa;
 550
 551         memset(&xfa, 0, sizeof(xfa));
 552         xfa.fsx_xflags = fa->fsx_xflags;
 553         xfa.fsx_extsize = fa->fsx_extsize;
 554         xfa.fsx_nextents = fa->fsx_nextents;
 555         xfa.fsx_projid = fa->fsx_projid;
 556         xfa.fsx_cowextsize = fa->fsx_cowextsize;
 557
 558         if (copy_to_user(ufa, &xfa, sizeof(xfa)))
 559                 return -EFAULT;
 560
 561         return 0;
 562 }
 563 EXPORT_SYMBOL(copy_fsxattr_to_user);
 564
 565 static int copy_fsxattr_from_user(struct fileattr *fa,
 566                                   struct fsxattr __user *ufa)
 567 {
 568         struct fsxattr xfa;
 569
 570         if (copy_from_user(&xfa, ufa, sizeof(xfa)))
 571                 return -EFAULT;
 572
 573         fileattr_fill_xflags(fa, xfa.fsx_xflags);
 574         fa->fsx_extsize = xfa.fsx_extsize;
 575         fa->fsx_nextents = xfa.fsx_nextents;
 576         fa->fsx_projid = xfa.fsx_projid;
 577         fa->fsx_cowextsize = xfa.fsx_cowextsize;
 578
 579         return 0;
 580 }
 581
 582 /*
 583  * Generic function to check FS_IOC_FSSETXATTR/FS_IOC_SETFLAGS values and reject
 584  * any invalid configurations.
 585  *
 586  * Note: must be called with inode lock held.
 587  */
 588 static int fileattr_set_prepare(struct inode *inode,
 589                               const struct fileattr *old_ma,
 590                               struct fileattr *fa)
 591 {
 592         int err;
 593
 594         /*
 595          * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 596          * the relevant capability.
 597          */
 598         if ((fa->flags ^ old_ma->flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL) &&
 599             !capable(CAP_LINUX_IMMUTABLE))
 600                 return -EPERM;
 601
 602         err = fscrypt_prepare_setflags(inode, old_ma->flags, fa->flags);
 603         if (err)
 604                 return err;
 605
 606         /*
 607          * Project Quota ID state is only allowed to change from within the init
 608          * namespace. Enforce that restriction only if we are trying to change
 609          * the quota ID state. Everything else is allowed in user namespaces.
 610          */
 611         if (current_user_ns() != &init_user_ns) {
 612                 if (old_ma->fsx_projid != fa->fsx_projid)
 613                         return -EINVAL;
 614                 if ((old_ma->fsx_xflags ^ fa->fsx_xflags) &
 615                                 FS_XFLAG_PROJINHERIT)
 616                         return -EINVAL;
 617         } else {
 618                 /*
 619                  * Caller is allowed to change the project ID. If it is being
 620                  * changed, make sure that the new value is valid.
 621                  */
 622                 if (old_ma->fsx_projid != fa->fsx_projid &&
 623                     !projid_valid(make_kprojid(&init_user_ns, fa->fsx_projid)))
 624                         return -EINVAL;
 625         }
 626
 627         /* Check extent size hints. */
 628         if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode))
 629                 return -EINVAL;
 630
 631         if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) &&
 632                         !S_ISDIR(inode->i_mode))
 633                 return -EINVAL;
 634
 635         if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) &&
 636             !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
 637                 return -EINVAL;
 638
 639         /*
 640          * It is only valid to set the DAX flag on regular files and
 641          * directories on filesystems.
 642          */
 643         if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
 644             !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
 645                 return -EINVAL;
 646
 647         /* Extent size hints of zero turn off the flags. */
 648         if (fa->fsx_extsize == 0)
 649                 fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);
 650         if (fa->fsx_cowextsize == 0)
 651                 fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE;
 652
 653         return 0;
 654 }
 655
 656 /**
 657  * vfs_fileattr_set - change miscellaneous file attributes
 658  * @mnt_userns: user namespace of the mount
 659  * @dentry:     the object to change
 660  * @fa:         fileattr pointer
 661  *
 662  * After verifying permissions, call i_op->fileattr_set() callback, if
 663  * exists.
 664  *
 665  * Verifying attributes involves retrieving current attributes with
 666  * i_op->fileattr_get(), this also allows initializing attributes that have
 667  * not been set by the caller to current values.  Inode lock is held
 668  * thoughout to prevent racing with another instance.
 669  *
 670  * Return: 0 on success, or a negative error on failure.
 671  */
 672 int vfs_fileattr_set(struct user_namespace *mnt_userns, struct dentry *dentry,
 673                      struct fileattr *fa)
 674 {
 675         struct inode *inode = d_inode(dentry);
 676         struct fileattr old_ma = {};
 677         int err;
 678
 679         if (!inode->i_op->fileattr_set)
 680                 return -ENOIOCTLCMD;
 681
 682         if (!inode_owner_or_capable(mnt_userns, inode))
 683                 return -EPERM;
 684
 685         inode_lock(inode);
 686         err = vfs_fileattr_get(dentry, &old_ma);
 687         if (!err) {
 688                 /* initialize missing bits from old_ma */
 689                 if (fa->flags_valid) {
 690                         fa->fsx_xflags |= old_ma.fsx_xflags & ~FS_XFLAG_COMMON;
 691                         fa->fsx_extsize = old_ma.fsx_extsize;
 692                         fa->fsx_nextents = old_ma.fsx_nextents;
 693                         fa->fsx_projid = old_ma.fsx_projid;
 694                         fa->fsx_cowextsize = old_ma.fsx_cowextsize;
 695                 } else {
 696                         fa->flags |= old_ma.flags & ~FS_COMMON_FL;
 697                 }
 698                 err = fileattr_set_prepare(inode, &old_ma, fa);
 699                 if (!err)
 700                         err = inode->i_op->fileattr_set(mnt_userns, dentry, fa);
 701         }
 702         inode_unlock(inode);
 703
 704         return err;
 705 }
 706 EXPORT_SYMBOL(vfs_fileattr_set);
 707
 708 static int ioctl_getflags(struct file *file, unsigned int __user *argp)
 709 {
 710         struct fileattr fa = { .flags_valid = true }; /* hint only */
 711         int err;
 712
 713         err = vfs_fileattr_get(file->f_path.dentry, &fa);
 714         if (!err)
 715                 err = put_user(fa.flags, argp);
 716         return err;
 717 }
 718
 719 static int ioctl_setflags(struct file *file, unsigned int __user *argp)
 720 {
 721         struct user_namespace *mnt_userns = file_mnt_user_ns(file);
 722         struct dentry *dentry = file->f_path.dentry;
 723         struct fileattr fa;
 724         unsigned int flags;
 725         int err;
 726
 727         err = get_user(flags, argp);
 728         if (!err) {
 729                 err = mnt_want_write_file(file);
 730                 if (!err) {
 731                         fileattr_fill_flags(&fa, flags);
 732                         err = vfs_fileattr_set(mnt_userns, dentry, &fa);
 733                         mnt_drop_write_file(file);
 734                 }
 735         }
 736         return err;
 737 }
 738
 739 static int ioctl_fsgetxattr(struct file *file, void __user *argp)
 740 {
 741         struct fileattr fa = { .fsx_valid = true }; /* hint only */
 742         int err;
 743
 744         err = vfs_fileattr_get(file->f_path.dentry, &fa);
 745         if (!err)
 746                 err = copy_fsxattr_to_user(&fa, argp);
 747
 748         return err;
 749 }
 750
 751 static int ioctl_fssetxattr(struct file *file, void __user *argp)
 752 {
 753         struct user_namespace *mnt_userns = file_mnt_user_ns(file);
 754         struct dentry *dentry = file->f_path.dentry;
 755         struct fileattr fa;
 756         int err;
 757
 758         err = copy_fsxattr_from_user(&fa, argp);
 759         if (!err) {
 760                 err = mnt_want_write_file(file);
 761                 if (!err) {
 762                         err = vfs_fileattr_set(mnt_userns, dentry, &fa);
 763                         mnt_drop_write_file(file);
 764                 }
 765         }
 766         return err;
 767 }
 768
 769 /*
 770  * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
 771  * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
 772  *
 773  * When you add any new common ioctls to the switches above and below,
 774  * please ensure they have compatible arguments in compat mode.
 775  */
 776 static int do_vfs_ioctl(struct file *filp, unsigned int fd,
 777                         unsigned int cmd, unsigned long arg)
 778 {
 779         void __user *argp = (void __user *)arg;
 780         struct inode *inode = file_inode(filp);
 781
 782         switch (cmd) {
 783         case FIOCLEX:
 784                 set_close_on_exec(fd, 1);
 785                 return 0;
 786
 787         case FIONCLEX:
 788                 set_close_on_exec(fd, 0);
 789                 return 0;
 790
 791         case FIONBIO:
 792                 return ioctl_fionbio(filp, argp);
 793
 794         case FIOASYNC:
 795                 return ioctl_fioasync(fd, filp, argp);
 796
 797         case FIOQSIZE:
 798                 if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
 799                     S_ISLNK(inode->i_mode)) {
 800                         loff_t res = inode_get_bytes(inode);
 801                         return copy_to_user(argp, &res, sizeof(res)) ?
 802                                             -EFAULT : 0;
 803                 }
 804
 805                 return -ENOTTY;
 806
 807         case FIFREEZE:
 808                 return ioctl_fsfreeze(filp);
 809
 810         case FITHAW:
 811                 return ioctl_fsthaw(filp);
 812
 813         case FS_IOC_FIEMAP:
 814                 return ioctl_fiemap(filp, argp);
 815
 816         case FIGETBSZ:
 817                 /* anon_bdev filesystems may not have a block size */
 818                 if (!inode->i_sb->s_blocksize)
 819                         return -EINVAL;
 820
 821                 return put_user(inode->i_sb->s_blocksize, (int __user *)argp);
 822
 823         case FICLONE:
 824                 return ioctl_file_clone(filp, arg, 0, 0, 0);
 825
 826         case FICLONERANGE:
 827                 return ioctl_file_clone_range(filp, argp);
 828
 829         case FIDEDUPERANGE:
 830                 return ioctl_file_dedupe_range(filp, argp);
 831
 832         case FIONREAD:
 833                 if (!S_ISREG(inode->i_mode))
 834                         return vfs_ioctl(filp, cmd, arg);
 835
 836                 return put_user(i_size_read(inode) - filp->f_pos,
 837                                 (int __user *)argp);
 838
 839         case FS_IOC_GETFLAGS:
 840                 return ioctl_getflags(filp, argp);
 841
 842         case FS_IOC_SETFLAGS:
 843                 return ioctl_setflags(filp, argp);
 844
 845         case FS_IOC_FSGETXATTR:
 846                 return ioctl_fsgetxattr(filp, argp);
 847
 848         case FS_IOC_FSSETXATTR:
 849                 return ioctl_fssetxattr(filp, argp);
 850
 851         default:
 852                 if (S_ISREG(inode->i_mode))
 853                         return file_ioctl(filp, cmd, argp);
 854                 break;
 855         }
 856
 857         return -ENOIOCTLCMD;
 858 }
 859
 860 SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
 861 {
 862         struct fd f = fdget(fd);
 863         int error;
 864
 865         if (!f.file)
 866                 return -EBADF;
 867
 868         error = security_file_ioctl(f.file, cmd, arg);
 869         if (error)
 870                 goto out;
 871
 872         error = do_vfs_ioctl(f.file, fd, cmd, arg);
 873         if (error == -ENOIOCTLCMD)
 874                 error = vfs_ioctl(f.file, cmd, arg);
 875
 876 out:
 877         fdput(f);
 878         return error;
 879 }
 880
 881 #ifdef CONFIG_COMPAT
 882 /**
 883  * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
 884  *
 885  * This is not normally called as a function, but instead set in struct
 886  * file_operations as
 887  *
 888  *     .compat_ioctl = compat_ptr_ioctl,
 889  *
 890  * On most architectures, the compat_ptr_ioctl() just passes all arguments
 891  * to the corresponding ->ioctl handler. The exception is arch/s390, where
 892  * compat_ptr() clears the top bit of a 32-bit pointer value, so user space
 893  * pointers to the second 2GB alias the first 2GB, as is the case for
 894  * native 32-bit s390 user space.
 895  *
 896  * The compat_ptr_ioctl() function must therefore be used only with ioctl
 897  * functions that either ignore the argument or pass a pointer to a
 898  * compatible data type.
 899  *
 900  * If any ioctl command handled by fops->unlocked_ioctl passes a plain
 901  * integer instead of a pointer, or any of the passed data types
 902  * is incompatible between 32-bit and 64-bit architectures, a proper
 903  * handler is required instead of compat_ptr_ioctl.
 904  */
 905 long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 906 {
 907         if (!file->f_op->unlocked_ioctl)
 908                 return -ENOIOCTLCMD;
 909
 910         return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 911 }
 912 EXPORT_SYMBOL(compat_ptr_ioctl);
 913
 914 COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
 915                        compat_ulong_t, arg)
 916 {
 917         struct fd f = fdget(fd);
 918         int error;
 919
 920         if (!f.file)
 921                 return -EBADF;
 922
 923         /* RED-PEN how should LSM module know it's handling 32bit? */
 924         error = security_file_ioctl(f.file, cmd, arg);
 925         if (error)
 926                 goto out;
 927
 928         switch (cmd) {
 929         /* FICLONE takes an int argument, so don't use compat_ptr() */
 930         case FICLONE:
 931                 error = ioctl_file_clone(f.file, arg, 0, 0, 0);
 932                 break;
 933
 934 #if defined(CONFIG_X86_64)
 935         /* these get messy on amd64 due to alignment differences */
 936         case FS_IOC_RESVSP_32:
 937         case FS_IOC_RESVSP64_32:
 938                 error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg));
 939                 break;
 940         case FS_IOC_UNRESVSP_32:
 941         case FS_IOC_UNRESVSP64_32:
 942                 error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE,
 943                                 compat_ptr(arg));
 944                 break;
 945         case FS_IOC_ZERO_RANGE_32:
 946                 error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE,
 947                                 compat_ptr(arg));
 948                 break;
 949 #endif
 950
 951         /*
 952          * These access 32-bit values anyway so no further handling is
 953          * necessary.
 954          */
 955         case FS_IOC32_GETFLAGS:
 956         case FS_IOC32_SETFLAGS:
 957                 cmd = (cmd == FS_IOC32_GETFLAGS) ?
 958                         FS_IOC_GETFLAGS : FS_IOC_SETFLAGS;
 959                 fallthrough;
 960         /*
 961          * everything else in do_vfs_ioctl() takes either a compatible
 962          * pointer argument or no argument -- call it with a modified
 963          * argument.
 964          */
 965         default:
 966                 error = do_vfs_ioctl(f.file, fd, cmd,
 967                                      (unsigned long)compat_ptr(arg));
 968                 if (error != -ENOIOCTLCMD)
 969                         break;
 970
 971                 if (f.file->f_op->compat_ioctl)
 972                         error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
 973                 if (error == -ENOIOCTLCMD)
 974                         error = -ENOTTY;
 975                 break;
 976         }
 977
 978  out:
 979         fdput(f);
 980
 981         return error;
 982 }
 983 #endif