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         cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
 240                                       olen, 0);
 241         if (cloned < 0)
 242                 ret = cloned;
 243         else if (olen && cloned != olen)
 244                 ret = -EINVAL;
 245         else
 246                 ret = 0;
 247         fdput(src_file);
 248         return ret;
 249 }
 250
 251 static long ioctl_file_clone_range(struct file *file,
 252                                    struct file_clone_range __user *argp)
 253 {
 254         struct file_clone_range args;
 255
 256         if (copy_from_user(&args, argp, sizeof(args)))
 257                 return -EFAULT;
 258         return ioctl_file_clone(file, args.src_fd, args.src_offset,
 259                                 args.src_length, args.dest_offset);
 260 }
 261
 262 /*
 263  * This provides compatibility with legacy XFS pre-allocation ioctls
 264  * which predate the fallocate syscall.
 265  *
 266  * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
 267  * are used here, rest are ignored.
 268  */
 269 static int ioctl_preallocate(struct file *filp, int mode, void __user *argp)
 270 {
 271         struct inode *inode = file_inode(filp);
 272         struct space_resv sr;
 273
 274         if (copy_from_user(&sr, argp, sizeof(sr)))
 275                 return -EFAULT;
 276
 277         switch (sr.l_whence) {
 278         case SEEK_SET:
 279                 break;
 280         case SEEK_CUR:
 281                 sr.l_start += filp->f_pos;
 282                 break;
 283         case SEEK_END:
 284                 sr.l_start += i_size_read(inode);
 285                 break;
 286         default:
 287                 return -EINVAL;
 288         }
 289
 290         return vfs_fallocate(filp, mode | FALLOC_FL_KEEP_SIZE, sr.l_start,
 291                         sr.l_len);
 292 }
 293
 294 /* on ia32 l_start is on a 32-bit boundary */
 295 #if defined CONFIG_COMPAT && defined(CONFIG_X86_64)
 296 /* just account for different alignment */
 297 static int compat_ioctl_preallocate(struct file *file, int mode,
 298                                     struct space_resv_32 __user *argp)
 299 {
 300         struct inode *inode = file_inode(file);
 301         struct space_resv_32 sr;
 302
 303         if (copy_from_user(&sr, argp, sizeof(sr)))
 304                 return -EFAULT;
 305
 306         switch (sr.l_whence) {
 307         case SEEK_SET:
 308                 break;
 309         case SEEK_CUR:
 310                 sr.l_start += file->f_pos;
 311                 break;
 312         case SEEK_END:
 313                 sr.l_start += i_size_read(inode);
 314                 break;
 315         default:
 316                 return -EINVAL;
 317         }
 318
 319         return vfs_fallocate(file, mode | FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
 320 }
 321 #endif
 322
 323 static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p)
 324 {
 325         switch (cmd) {
 326         case FIBMAP:
 327                 return ioctl_fibmap(filp, p);
 328         case FS_IOC_RESVSP:
 329         case FS_IOC_RESVSP64:
 330                 return ioctl_preallocate(filp, 0, p);
 331         case FS_IOC_UNRESVSP:
 332         case FS_IOC_UNRESVSP64:
 333                 return ioctl_preallocate(filp, FALLOC_FL_PUNCH_HOLE, p);
 334         case FS_IOC_ZERO_RANGE:
 335                 return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p);
 336         }
 337
 338         return -ENOIOCTLCMD;
 339 }
 340
 341 static int ioctl_fionbio(struct file *filp, int __user *argp)
 342 {
 343         unsigned int flag;
 344         int on, error;
 345
 346         error = get_user(on, argp);
 347         if (error)
 348                 return error;
 349         flag = O_NONBLOCK;
 350 #ifdef __sparc__
 351         /* SunOS compatibility item. */
 352         if (O_NONBLOCK != O_NDELAY)
 353                 flag |= O_NDELAY;
 354 #endif
 355         spin_lock(&filp->f_lock);
 356         if (on)
 357                 filp->f_flags |= flag;
 358         else
 359                 filp->f_flags &= ~flag;
 360         spin_unlock(&filp->f_lock);
 361         return error;
 362 }
 363
 364 static int ioctl_fioasync(unsigned int fd, struct file *filp,
 365                           int __user *argp)
 366 {
 367         unsigned int flag;
 368         int on, error;
 369
 370         error = get_user(on, argp);
 371         if (error)
 372                 return error;
 373         flag = on ? FASYNC : 0;
 374
 375         /* Did FASYNC state change ? */
 376         if ((flag ^ filp->f_flags) & FASYNC) {
 377                 if (filp->f_op->fasync)
 378                         /* fasync() adjusts filp->f_flags */
 379                         error = filp->f_op->fasync(fd, filp, on);
 380                 else
 381                         error = -ENOTTY;
 382         }
 383         return error < 0 ? error : 0;
 384 }
 385
 386 static int ioctl_fsfreeze(struct file *filp)
 387 {
 388         struct super_block *sb = file_inode(filp)->i_sb;
 389
 390         if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 391                 return -EPERM;
 392
 393         /* If filesystem doesn't support freeze feature, return. */
 394         if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
 395                 return -EOPNOTSUPP;
 396
 397         /* Freeze */
 398         if (sb->s_op->freeze_super)
 399                 return sb->s_op->freeze_super(sb);
 400         return freeze_super(sb);
 401 }
 402
 403 static int ioctl_fsthaw(struct file *filp)
 404 {
 405         struct super_block *sb = file_inode(filp)->i_sb;
 406
 407         if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 408                 return -EPERM;
 409
 410         /* Thaw */
 411         if (sb->s_op->thaw_super)
 412                 return sb->s_op->thaw_super(sb);
 413         return thaw_super(sb);
 414 }
 415
 416 static int ioctl_file_dedupe_range(struct file *file,
 417                                    struct file_dedupe_range __user *argp)
 418 {
 419         struct file_dedupe_range *same = NULL;
 420         int ret;
 421         unsigned long size;
 422         u16 count;
 423
 424         if (get_user(count, &argp->dest_count)) {
 425                 ret = -EFAULT;
 426                 goto out;
 427         }
 428
 429         size = offsetof(struct file_dedupe_range, info[count]);
 430         if (size > PAGE_SIZE) {
 431                 ret = -ENOMEM;
 432                 goto out;
 433         }
 434
 435         same = memdup_user(argp, size);
 436         if (IS_ERR(same)) {
 437                 ret = PTR_ERR(same);
 438                 same = NULL;
 439                 goto out;
 440         }
 441
 442         same->dest_count = count;
 443         ret = vfs_dedupe_file_range(file, same);
 444         if (ret)
 445                 goto out;
 446
 447         ret = copy_to_user(argp, same, size);
 448         if (ret)
 449                 ret = -EFAULT;
 450
 451 out:
 452         kfree(same);
 453         return ret;
 454 }
 455
 456 /**
 457  * fileattr_fill_xflags - initialize fileattr with xflags
 458  * @fa:         fileattr pointer
 459  * @xflags:     FS_XFLAG_* flags
 460  *
 461  * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags).  All
 462  * other fields are zeroed.
 463  */
 464 void fileattr_fill_xflags(struct fileattr *fa, u32 xflags)
 465 {
 466         memset(fa, 0, sizeof(*fa));
 467         fa->fsx_valid = true;
 468         fa->fsx_xflags = xflags;
 469         if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE)
 470                 fa->flags |= FS_IMMUTABLE_FL;
 471         if (fa->fsx_xflags & FS_XFLAG_APPEND)
 472                 fa->flags |= FS_APPEND_FL;
 473         if (fa->fsx_xflags & FS_XFLAG_SYNC)
 474                 fa->flags |= FS_SYNC_FL;
 475         if (fa->fsx_xflags & FS_XFLAG_NOATIME)
 476                 fa->flags |= FS_NOATIME_FL;
 477         if (fa->fsx_xflags & FS_XFLAG_NODUMP)
 478                 fa->flags |= FS_NODUMP_FL;
 479         if (fa->fsx_xflags & FS_XFLAG_DAX)
 480                 fa->flags |= FS_DAX_FL;
 481         if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
 482                 fa->flags |= FS_PROJINHERIT_FL;
 483 }
 484 EXPORT_SYMBOL(fileattr_fill_xflags);
 485
 486 /**
 487  * fileattr_fill_flags - initialize fileattr with flags
 488  * @fa:         fileattr pointer
 489  * @flags:      FS_*_FL flags
 490  *
 491  * Set ->flags, ->flags_valid and ->fsx_xflags (translated flags).
 492  * All other fields are zeroed.
 493  */
 494 void fileattr_fill_flags(struct fileattr *fa, u32 flags)
 495 {
 496         memset(fa, 0, sizeof(*fa));
 497         fa->flags_valid = true;
 498         fa->flags = flags;
 499         if (fa->flags & FS_SYNC_FL)
 500                 fa->fsx_xflags |= FS_XFLAG_SYNC;
 501         if (fa->flags & FS_IMMUTABLE_FL)
 502                 fa->fsx_xflags |= FS_XFLAG_IMMUTABLE;
 503         if (fa->flags & FS_APPEND_FL)
 504                 fa->fsx_xflags |= FS_XFLAG_APPEND;
 505         if (fa->flags & FS_NODUMP_FL)
 506                 fa->fsx_xflags |= FS_XFLAG_NODUMP;
 507         if (fa->flags & FS_NOATIME_FL)
 508                 fa->fsx_xflags |= FS_XFLAG_NOATIME;
 509         if (fa->flags & FS_DAX_FL)
 510                 fa->fsx_xflags |= FS_XFLAG_DAX;
 511         if (fa->flags & FS_PROJINHERIT_FL)
 512                 fa->fsx_xflags |= FS_XFLAG_PROJINHERIT;
 513 }
 514 EXPORT_SYMBOL(fileattr_fill_flags);
 515
 516 /**
 517  * vfs_fileattr_get - retrieve miscellaneous file attributes
 518  * @dentry:     the object to retrieve from
 519  * @fa:         fileattr pointer
 520  *
 521  * Call i_op->fileattr_get() callback, if exists.
 522  *
 523  * Return: 0 on success, or a negative error on failure.
 524  */
 525 int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 526 {
 527         struct inode *inode = d_inode(dentry);
 528
 529         if (!inode->i_op->fileattr_get)
 530                 return -ENOIOCTLCMD;
 531
 532         return inode->i_op->fileattr_get(dentry, fa);
 533 }
 534 EXPORT_SYMBOL(vfs_fileattr_get);
 535
 536 /**
 537  * copy_fsxattr_to_user - copy fsxattr to userspace.
 538  * @fa:         fileattr pointer
 539  * @ufa:        fsxattr user pointer
 540  *
 541  * Return: 0 on success, or -EFAULT on failure.
 542  */
 543 int copy_fsxattr_to_user(const struct fileattr *fa, struct fsxattr __user *ufa)
 544 {
 545         struct fsxattr xfa;
 546
 547         memset(&xfa, 0, sizeof(xfa));
 548         xfa.fsx_xflags = fa->fsx_xflags;
 549         xfa.fsx_extsize = fa->fsx_extsize;
 550         xfa.fsx_nextents = fa->fsx_nextents;
 551         xfa.fsx_projid = fa->fsx_projid;
 552         xfa.fsx_cowextsize = fa->fsx_cowextsize;
 553
 554         if (copy_to_user(ufa, &xfa, sizeof(xfa)))
 555                 return -EFAULT;
 556
 557         return 0;
 558 }
 559 EXPORT_SYMBOL(copy_fsxattr_to_user);
 560
 561 static int copy_fsxattr_from_user(struct fileattr *fa,
 562                                   struct fsxattr __user *ufa)
 563 {
 564         struct fsxattr xfa;
 565
 566         if (copy_from_user(&xfa, ufa, sizeof(xfa)))
 567                 return -EFAULT;
 568
 569         fileattr_fill_xflags(fa, xfa.fsx_xflags);
 570         fa->fsx_extsize = xfa.fsx_extsize;
 571         fa->fsx_nextents = xfa.fsx_nextents;
 572         fa->fsx_projid = xfa.fsx_projid;
 573         fa->fsx_cowextsize = xfa.fsx_cowextsize;
 574
 575         return 0;
 576 }
 577
 578 /*
 579  * Generic function to check FS_IOC_FSSETXATTR/FS_IOC_SETFLAGS values and reject
 580  * any invalid configurations.
 581  *
 582  * Note: must be called with inode lock held.
 583  */
 584 static int fileattr_set_prepare(struct inode *inode,
 585                               const struct fileattr *old_ma,
 586                               struct fileattr *fa)
 587 {
 588         int err;
 589
 590         /*
 591          * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 592          * the relevant capability.
 593          */
 594         if ((fa->flags ^ old_ma->flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL) &&
 595             !capable(CAP_LINUX_IMMUTABLE))
 596                 return -EPERM;
 597
 598         err = fscrypt_prepare_setflags(inode, old_ma->flags, fa->flags);
 599         if (err)
 600                 return err;
 601
 602         /*
 603          * Project Quota ID state is only allowed to change from within the init
 604          * namespace. Enforce that restriction only if we are trying to change
 605          * the quota ID state. Everything else is allowed in user namespaces.
 606          */
 607         if (current_user_ns() != &init_user_ns) {
 608                 if (old_ma->fsx_projid != fa->fsx_projid)
 609                         return -EINVAL;
 610                 if ((old_ma->fsx_xflags ^ fa->fsx_xflags) &
 611                                 FS_XFLAG_PROJINHERIT)
 612                         return -EINVAL;
 613         } else {
 614                 /*
 615                  * Caller is allowed to change the project ID. If it is being
 616                  * changed, make sure that the new value is valid.
 617                  */
 618                 if (old_ma->fsx_projid != fa->fsx_projid &&
 619                     !projid_valid(make_kprojid(&init_user_ns, fa->fsx_projid)))
 620                         return -EINVAL;
 621         }
 622
 623         /* Check extent size hints. */
 624         if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode))
 625                 return -EINVAL;
 626
 627         if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) &&
 628                         !S_ISDIR(inode->i_mode))
 629                 return -EINVAL;
 630
 631         if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) &&
 632             !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
 633                 return -EINVAL;
 634
 635         /*
 636          * It is only valid to set the DAX flag on regular files and
 637          * directories on filesystems.
 638          */
 639         if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
 640             !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
 641                 return -EINVAL;
 642
 643         /* Extent size hints of zero turn off the flags. */
 644         if (fa->fsx_extsize == 0)
 645                 fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);
 646         if (fa->fsx_cowextsize == 0)
 647                 fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE;
 648
 649         return 0;
 650 }
 651
 652 /**
 653  * vfs_fileattr_set - change miscellaneous file attributes
 654  * @mnt_userns: user namespace of the mount
 655  * @dentry:     the object to change
 656  * @fa:         fileattr pointer
 657  *
 658  * After verifying permissions, call i_op->fileattr_set() callback, if
 659  * exists.
 660  *
 661  * Verifying attributes involves retrieving current attributes with
 662  * i_op->fileattr_get(), this also allows initializing attributes that have
 663  * not been set by the caller to current values.  Inode lock is held
 664  * thoughout to prevent racing with another instance.
 665  *
 666  * Return: 0 on success, or a negative error on failure.
 667  */
 668 int vfs_fileattr_set(struct user_namespace *mnt_userns, struct dentry *dentry,
 669                      struct fileattr *fa)
 670 {
 671         struct inode *inode = d_inode(dentry);
 672         struct fileattr old_ma = {};
 673         int err;
 674
 675         if (!inode->i_op->fileattr_set)
 676                 return -ENOIOCTLCMD;
 677
 678         if (!inode_owner_or_capable(mnt_userns, inode))
 679                 return -EPERM;
 680
 681         inode_lock(inode);
 682         err = vfs_fileattr_get(dentry, &old_ma);
 683         if (!err) {
 684                 /* initialize missing bits from old_ma */
 685                 if (fa->flags_valid) {
 686                         fa->fsx_xflags |= old_ma.fsx_xflags & ~FS_XFLAG_COMMON;
 687                         fa->fsx_extsize = old_ma.fsx_extsize;
 688                         fa->fsx_nextents = old_ma.fsx_nextents;
 689                         fa->fsx_projid = old_ma.fsx_projid;
 690                         fa->fsx_cowextsize = old_ma.fsx_cowextsize;
 691                 } else {
 692                         fa->flags |= old_ma.flags & ~FS_COMMON_FL;
 693                 }
 694                 err = fileattr_set_prepare(inode, &old_ma, fa);
 695                 if (!err)
 696                         err = inode->i_op->fileattr_set(mnt_userns, dentry, fa);
 697         }
 698         inode_unlock(inode);
 699
 700         return err;
 701 }
 702 EXPORT_SYMBOL(vfs_fileattr_set);
 703
 704 static int ioctl_getflags(struct file *file, unsigned int __user *argp)
 705 {
 706         struct fileattr fa = { .flags_valid = true }; /* hint only */
 707         int err;
 708
 709         err = vfs_fileattr_get(file->f_path.dentry, &fa);
 710         if (!err)
 711                 err = put_user(fa.flags, argp);
 712         return err;
 713 }
 714
 715 static int ioctl_setflags(struct file *file, unsigned int __user *argp)
 716 {
 717         struct user_namespace *mnt_userns = file_mnt_user_ns(file);
 718         struct dentry *dentry = file->f_path.dentry;
 719         struct fileattr fa;
 720         unsigned int flags;
 721         int err;
 722
 723         err = get_user(flags, argp);
 724         if (!err) {
 725                 err = mnt_want_write_file(file);
 726                 if (!err) {
 727                         fileattr_fill_flags(&fa, flags);
 728                         err = vfs_fileattr_set(mnt_userns, dentry, &fa);
 729                         mnt_drop_write_file(file);
 730                 }
 731         }
 732         return err;
 733 }
 734
 735 static int ioctl_fsgetxattr(struct file *file, void __user *argp)
 736 {
 737         struct fileattr fa = { .fsx_valid = true }; /* hint only */
 738         int err;
 739
 740         err = vfs_fileattr_get(file->f_path.dentry, &fa);
 741         if (!err)
 742                 err = copy_fsxattr_to_user(&fa, argp);
 743
 744         return err;
 745 }
 746
 747 static int ioctl_fssetxattr(struct file *file, void __user *argp)
 748 {
 749         struct user_namespace *mnt_userns = file_mnt_user_ns(file);
 750         struct dentry *dentry = file->f_path.dentry;
 751         struct fileattr fa;
 752         int err;
 753
 754         err = copy_fsxattr_from_user(&fa, argp);
 755         if (!err) {
 756                 err = mnt_want_write_file(file);
 757                 if (!err) {
 758                         err = vfs_fileattr_set(mnt_userns, dentry, &fa);
 759                         mnt_drop_write_file(file);
 760                 }
 761         }
 762         return err;
 763 }
 764
 765 /*
 766  * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
 767  * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
 768  *
 769  * When you add any new common ioctls to the switches above and below,
 770  * please ensure they have compatible arguments in compat mode.
 771  */
 772 static int do_vfs_ioctl(struct file *filp, unsigned int fd,
 773                         unsigned int cmd, unsigned long arg)
 774 {
 775         void __user *argp = (void __user *)arg;
 776         struct inode *inode = file_inode(filp);
 777
 778         switch (cmd) {
 779         case FIOCLEX:
 780                 set_close_on_exec(fd, 1);
 781                 return 0;
 782
 783         case FIONCLEX:
 784                 set_close_on_exec(fd, 0);
 785                 return 0;
 786
 787         case FIONBIO:
 788                 return ioctl_fionbio(filp, argp);
 789
 790         case FIOASYNC:
 791                 return ioctl_fioasync(fd, filp, argp);
 792
 793         case FIOQSIZE:
 794                 if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
 795                     S_ISLNK(inode->i_mode)) {
 796                         loff_t res = inode_get_bytes(inode);
 797                         return copy_to_user(argp, &res, sizeof(res)) ?
 798                                             -EFAULT : 0;
 799                 }
 800
 801                 return -ENOTTY;
 802
 803         case FIFREEZE:
 804                 return ioctl_fsfreeze(filp);
 805
 806         case FITHAW:
 807                 return ioctl_fsthaw(filp);
 808
 809         case FS_IOC_FIEMAP:
 810                 return ioctl_fiemap(filp, argp);
 811
 812         case FIGETBSZ:
 813                 /* anon_bdev filesystems may not have a block size */
 814                 if (!inode->i_sb->s_blocksize)
 815                         return -EINVAL;
 816
 817                 return put_user(inode->i_sb->s_blocksize, (int __user *)argp);
 818
 819         case FICLONE:
 820                 return ioctl_file_clone(filp, arg, 0, 0, 0);
 821
 822         case FICLONERANGE:
 823                 return ioctl_file_clone_range(filp, argp);
 824
 825         case FIDEDUPERANGE:
 826                 return ioctl_file_dedupe_range(filp, argp);
 827
 828         case FIONREAD:
 829                 if (!S_ISREG(inode->i_mode))
 830                         return vfs_ioctl(filp, cmd, arg);
 831
 832                 return put_user(i_size_read(inode) - filp->f_pos,
 833                                 (int __user *)argp);
 834
 835         case FS_IOC_GETFLAGS:
 836                 return ioctl_getflags(filp, argp);
 837
 838         case FS_IOC_SETFLAGS:
 839                 return ioctl_setflags(filp, argp);
 840
 841         case FS_IOC_FSGETXATTR:
 842                 return ioctl_fsgetxattr(filp, argp);
 843
 844         case FS_IOC_FSSETXATTR:
 845                 return ioctl_fssetxattr(filp, argp);
 846
 847         default:
 848                 if (S_ISREG(inode->i_mode))
 849                         return file_ioctl(filp, cmd, argp);
 850                 break;
 851         }
 852
 853         return -ENOIOCTLCMD;
 854 }
 855
 856 SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
 857 {
 858         struct fd f = fdget(fd);
 859         int error;
 860
 861         if (!f.file)
 862                 return -EBADF;
 863
 864         error = security_file_ioctl(f.file, cmd, arg);
 865         if (error)
 866                 goto out;
 867
 868         error = do_vfs_ioctl(f.file, fd, cmd, arg);
 869         if (error == -ENOIOCTLCMD)
 870                 error = vfs_ioctl(f.file, cmd, arg);
 871
 872 out:
 873         fdput(f);
 874         return error;
 875 }
 876
 877 #ifdef CONFIG_COMPAT
 878 /**
 879  * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
 880  *
 881  * This is not normally called as a function, but instead set in struct
 882  * file_operations as
 883  *
 884  *     .compat_ioctl = compat_ptr_ioctl,
 885  *
 886  * On most architectures, the compat_ptr_ioctl() just passes all arguments
 887  * to the corresponding ->ioctl handler. The exception is arch/s390, where
 888  * compat_ptr() clears the top bit of a 32-bit pointer value, so user space
 889  * pointers to the second 2GB alias the first 2GB, as is the case for
 890  * native 32-bit s390 user space.
 891  *
 892  * The compat_ptr_ioctl() function must therefore be used only with ioctl
 893  * functions that either ignore the argument or pass a pointer to a
 894  * compatible data type.
 895  *
 896  * If any ioctl command handled by fops->unlocked_ioctl passes a plain
 897  * integer instead of a pointer, or any of the passed data types
 898  * is incompatible between 32-bit and 64-bit architectures, a proper
 899  * handler is required instead of compat_ptr_ioctl.
 900  */
 901 long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 902 {
 903         if (!file->f_op->unlocked_ioctl)
 904                 return -ENOIOCTLCMD;
 905
 906         return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 907 }
 908 EXPORT_SYMBOL(compat_ptr_ioctl);
 909
 910 COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
 911                        compat_ulong_t, arg)
 912 {
 913         struct fd f = fdget(fd);
 914         int error;
 915
 916         if (!f.file)
 917                 return -EBADF;
 918
 919         /* RED-PEN how should LSM module know it's handling 32bit? */
 920         error = security_file_ioctl(f.file, cmd, arg);
 921         if (error)
 922                 goto out;
 923
 924         switch (cmd) {
 925         /* FICLONE takes an int argument, so don't use compat_ptr() */
 926         case FICLONE:
 927                 error = ioctl_file_clone(f.file, arg, 0, 0, 0);
 928                 break;
 929
 930 #if defined(CONFIG_X86_64)
 931         /* these get messy on amd64 due to alignment differences */
 932         case FS_IOC_RESVSP_32:
 933         case FS_IOC_RESVSP64_32:
 934                 error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg));
 935                 break;
 936         case FS_IOC_UNRESVSP_32:
 937         case FS_IOC_UNRESVSP64_32:
 938                 error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE,
 939                                 compat_ptr(arg));
 940                 break;
 941         case FS_IOC_ZERO_RANGE_32:
 942                 error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE,
 943                                 compat_ptr(arg));
 944                 break;
 945 #endif
 946
 947         /*
 948          * These access 32-bit values anyway so no further handling is
 949          * necessary.
 950          */
 951         case FS_IOC32_GETFLAGS:
 952         case FS_IOC32_SETFLAGS:
 953                 cmd = (cmd == FS_IOC32_GETFLAGS) ?
 954                         FS_IOC_GETFLAGS : FS_IOC_SETFLAGS;
 955                 fallthrough;
 956         /*
 957          * everything else in do_vfs_ioctl() takes either a compatible
 958          * pointer argument or no argument -- call it with a modified
 959          * argument.
 960          */
 961         default:
 962                 error = do_vfs_ioctl(f.file, fd, cmd,
 963                                      (unsigned long)compat_ptr(arg));
 964                 if (error != -ENOIOCTLCMD)
 965                         break;
 966
 967                 if (f.file->f_op->compat_ioctl)
 968                         error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
 969                 if (error == -ENOIOCTLCMD)
 970                         error = -ENOTTY;
 971                 break;
 972         }
 973
 974  out:
 975         fdput(f);
 976
 977         return error;
 978 }
 979 #endif