xref: /openbmc/linux/fs/ioctl.c (revision 820831de)
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  */
vfs_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)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 
ioctl_fibmap(struct file * filp,int __user * p)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  */
fiemap_fill_next_extent(struct fiemap_extent_info * fieinfo,u64 logical,u64 phys,u64 len,u32 flags)112 int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
113 			    u64 phys, u64 len, u32 flags)
114 {
115 	struct fiemap_extent extent;
116 	struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
117 
118 	/* only count the extents */
119 	if (fieinfo->fi_extents_max == 0) {
120 		fieinfo->fi_extents_mapped++;
121 		return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
122 	}
123 
124 	if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
125 		return 1;
126 
127 #define SET_UNKNOWN_FLAGS	(FIEMAP_EXTENT_DELALLOC)
128 #define SET_NO_UNMOUNTED_IO_FLAGS	(FIEMAP_EXTENT_DATA_ENCRYPTED)
129 #define SET_NOT_ALIGNED_FLAGS	(FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
130 
131 	if (flags & SET_UNKNOWN_FLAGS)
132 		flags |= FIEMAP_EXTENT_UNKNOWN;
133 	if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
134 		flags |= FIEMAP_EXTENT_ENCODED;
135 	if (flags & SET_NOT_ALIGNED_FLAGS)
136 		flags |= FIEMAP_EXTENT_NOT_ALIGNED;
137 
138 	memset(&extent, 0, sizeof(extent));
139 	extent.fe_logical = logical;
140 	extent.fe_physical = phys;
141 	extent.fe_length = len;
142 	extent.fe_flags = flags;
143 
144 	dest += fieinfo->fi_extents_mapped;
145 	if (copy_to_user(dest, &extent, sizeof(extent)))
146 		return -EFAULT;
147 
148 	fieinfo->fi_extents_mapped++;
149 	if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
150 		return 1;
151 	return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
152 }
153 EXPORT_SYMBOL(fiemap_fill_next_extent);
154 
155 /**
156  * fiemap_prep - check validity of requested flags for fiemap
157  * @inode:	Inode to operate on
158  * @fieinfo:	Fiemap context passed into ->fiemap
159  * @start:	Start of the mapped range
160  * @len:	Length of the mapped range, can be truncated by this function.
161  * @supported_flags:	Set of fiemap flags that the file system understands
162  *
163  * This function must be called from each ->fiemap instance to validate the
164  * fiemap request against the file system parameters.
165  *
166  * Returns 0 on success, or a negative error on failure.
167  */
fiemap_prep(struct inode * inode,struct fiemap_extent_info * fieinfo,u64 start,u64 * len,u32 supported_flags)168 int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo,
169 		u64 start, u64 *len, u32 supported_flags)
170 {
171 	u64 maxbytes = inode->i_sb->s_maxbytes;
172 	u32 incompat_flags;
173 	int ret = 0;
174 
175 	if (*len == 0)
176 		return -EINVAL;
177 	if (start >= maxbytes)
178 		return -EFBIG;
179 
180 	/*
181 	 * Shrink request scope to what the fs can actually handle.
182 	 */
183 	if (*len > maxbytes || (maxbytes - *len) < start)
184 		*len = maxbytes - start;
185 
186 	supported_flags |= FIEMAP_FLAG_SYNC;
187 	supported_flags &= FIEMAP_FLAGS_COMPAT;
188 	incompat_flags = fieinfo->fi_flags & ~supported_flags;
189 	if (incompat_flags) {
190 		fieinfo->fi_flags = incompat_flags;
191 		return -EBADR;
192 	}
193 
194 	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
195 		ret = filemap_write_and_wait(inode->i_mapping);
196 	return ret;
197 }
198 EXPORT_SYMBOL(fiemap_prep);
199 
ioctl_fiemap(struct file * filp,struct fiemap __user * ufiemap)200 static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
201 {
202 	struct fiemap fiemap;
203 	struct fiemap_extent_info fieinfo = { 0, };
204 	struct inode *inode = file_inode(filp);
205 	int error;
206 
207 	if (!inode->i_op->fiemap)
208 		return -EOPNOTSUPP;
209 
210 	if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
211 		return -EFAULT;
212 
213 	if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
214 		return -EINVAL;
215 
216 	fieinfo.fi_flags = fiemap.fm_flags;
217 	fieinfo.fi_extents_max = fiemap.fm_extent_count;
218 	fieinfo.fi_extents_start = ufiemap->fm_extents;
219 
220 	error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
221 			fiemap.fm_length);
222 
223 	fiemap.fm_flags = fieinfo.fi_flags;
224 	fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
225 	if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
226 		error = -EFAULT;
227 
228 	return error;
229 }
230 
ioctl_file_clone(struct file * dst_file,unsigned long srcfd,u64 off,u64 olen,u64 destoff)231 static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
232 			     u64 off, u64 olen, u64 destoff)
233 {
234 	struct fd src_file = fdget(srcfd);
235 	loff_t cloned;
236 	int ret;
237 
238 	if (!src_file.file)
239 		return -EBADF;
240 	cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
241 				      olen, 0);
242 	if (cloned < 0)
243 		ret = cloned;
244 	else if (olen && cloned != olen)
245 		ret = -EINVAL;
246 	else
247 		ret = 0;
248 	fdput(src_file);
249 	return ret;
250 }
251 
ioctl_file_clone_range(struct file * file,struct file_clone_range __user * argp)252 static long ioctl_file_clone_range(struct file *file,
253 				   struct file_clone_range __user *argp)
254 {
255 	struct file_clone_range args;
256 
257 	if (copy_from_user(&args, argp, sizeof(args)))
258 		return -EFAULT;
259 	return ioctl_file_clone(file, args.src_fd, args.src_offset,
260 				args.src_length, args.dest_offset);
261 }
262 
263 /*
264  * This provides compatibility with legacy XFS pre-allocation ioctls
265  * which predate the fallocate syscall.
266  *
267  * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
268  * are used here, rest are ignored.
269  */
ioctl_preallocate(struct file * filp,int mode,void __user * argp)270 static int ioctl_preallocate(struct file *filp, int mode, void __user *argp)
271 {
272 	struct inode *inode = file_inode(filp);
273 	struct space_resv sr;
274 
275 	if (copy_from_user(&sr, argp, sizeof(sr)))
276 		return -EFAULT;
277 
278 	switch (sr.l_whence) {
279 	case SEEK_SET:
280 		break;
281 	case SEEK_CUR:
282 		sr.l_start += filp->f_pos;
283 		break;
284 	case SEEK_END:
285 		sr.l_start += i_size_read(inode);
286 		break;
287 	default:
288 		return -EINVAL;
289 	}
290 
291 	return vfs_fallocate(filp, mode | FALLOC_FL_KEEP_SIZE, sr.l_start,
292 			sr.l_len);
293 }
294 
295 /* on ia32 l_start is on a 32-bit boundary */
296 #if defined CONFIG_COMPAT && defined(CONFIG_X86_64)
297 /* just account for different alignment */
compat_ioctl_preallocate(struct file * file,int mode,struct space_resv_32 __user * argp)298 static int compat_ioctl_preallocate(struct file *file, int mode,
299 				    struct space_resv_32 __user *argp)
300 {
301 	struct inode *inode = file_inode(file);
302 	struct space_resv_32 sr;
303 
304 	if (copy_from_user(&sr, argp, sizeof(sr)))
305 		return -EFAULT;
306 
307 	switch (sr.l_whence) {
308 	case SEEK_SET:
309 		break;
310 	case SEEK_CUR:
311 		sr.l_start += file->f_pos;
312 		break;
313 	case SEEK_END:
314 		sr.l_start += i_size_read(inode);
315 		break;
316 	default:
317 		return -EINVAL;
318 	}
319 
320 	return vfs_fallocate(file, mode | FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
321 }
322 #endif
323 
file_ioctl(struct file * filp,unsigned int cmd,int __user * p)324 static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p)
325 {
326 	switch (cmd) {
327 	case FIBMAP:
328 		return ioctl_fibmap(filp, p);
329 	case FS_IOC_RESVSP:
330 	case FS_IOC_RESVSP64:
331 		return ioctl_preallocate(filp, 0, p);
332 	case FS_IOC_UNRESVSP:
333 	case FS_IOC_UNRESVSP64:
334 		return ioctl_preallocate(filp, FALLOC_FL_PUNCH_HOLE, p);
335 	case FS_IOC_ZERO_RANGE:
336 		return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p);
337 	}
338 
339 	return -ENOIOCTLCMD;
340 }
341 
ioctl_fionbio(struct file * filp,int __user * argp)342 static int ioctl_fionbio(struct file *filp, int __user *argp)
343 {
344 	unsigned int flag;
345 	int on, error;
346 
347 	error = get_user(on, argp);
348 	if (error)
349 		return error;
350 	flag = O_NONBLOCK;
351 #ifdef __sparc__
352 	/* SunOS compatibility item. */
353 	if (O_NONBLOCK != O_NDELAY)
354 		flag |= O_NDELAY;
355 #endif
356 	spin_lock(&filp->f_lock);
357 	if (on)
358 		filp->f_flags |= flag;
359 	else
360 		filp->f_flags &= ~flag;
361 	spin_unlock(&filp->f_lock);
362 	return error;
363 }
364 
ioctl_fioasync(unsigned int fd,struct file * filp,int __user * argp)365 static int ioctl_fioasync(unsigned int fd, struct file *filp,
366 			  int __user *argp)
367 {
368 	unsigned int flag;
369 	int on, error;
370 
371 	error = get_user(on, argp);
372 	if (error)
373 		return error;
374 	flag = on ? FASYNC : 0;
375 
376 	/* Did FASYNC state change ? */
377 	if ((flag ^ filp->f_flags) & FASYNC) {
378 		if (filp->f_op->fasync)
379 			/* fasync() adjusts filp->f_flags */
380 			error = filp->f_op->fasync(fd, filp, on);
381 		else
382 			error = -ENOTTY;
383 	}
384 	return error < 0 ? error : 0;
385 }
386 
ioctl_fsfreeze(struct file * filp)387 static int ioctl_fsfreeze(struct file *filp)
388 {
389 	struct super_block *sb = file_inode(filp)->i_sb;
390 
391 	if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
392 		return -EPERM;
393 
394 	/* If filesystem doesn't support freeze feature, return. */
395 	if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
396 		return -EOPNOTSUPP;
397 
398 	/* Freeze */
399 	if (sb->s_op->freeze_super)
400 		return sb->s_op->freeze_super(sb, FREEZE_HOLDER_USERSPACE);
401 	return freeze_super(sb, FREEZE_HOLDER_USERSPACE);
402 }
403 
ioctl_fsthaw(struct file * filp)404 static int ioctl_fsthaw(struct file *filp)
405 {
406 	struct super_block *sb = file_inode(filp)->i_sb;
407 
408 	if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
409 		return -EPERM;
410 
411 	/* Thaw */
412 	if (sb->s_op->thaw_super)
413 		return sb->s_op->thaw_super(sb, FREEZE_HOLDER_USERSPACE);
414 	return thaw_super(sb, FREEZE_HOLDER_USERSPACE);
415 }
416 
ioctl_file_dedupe_range(struct file * file,struct file_dedupe_range __user * argp)417 static int ioctl_file_dedupe_range(struct file *file,
418 				   struct file_dedupe_range __user *argp)
419 {
420 	struct file_dedupe_range *same = NULL;
421 	int ret;
422 	unsigned long size;
423 	u16 count;
424 
425 	if (get_user(count, &argp->dest_count)) {
426 		ret = -EFAULT;
427 		goto out;
428 	}
429 
430 	size = offsetof(struct file_dedupe_range, info[count]);
431 	if (size > PAGE_SIZE) {
432 		ret = -ENOMEM;
433 		goto out;
434 	}
435 
436 	same = memdup_user(argp, size);
437 	if (IS_ERR(same)) {
438 		ret = PTR_ERR(same);
439 		same = NULL;
440 		goto out;
441 	}
442 
443 	same->dest_count = count;
444 	ret = vfs_dedupe_file_range(file, same);
445 	if (ret)
446 		goto out;
447 
448 	ret = copy_to_user(argp, same, size);
449 	if (ret)
450 		ret = -EFAULT;
451 
452 out:
453 	kfree(same);
454 	return ret;
455 }
456 
457 /**
458  * fileattr_fill_xflags - initialize fileattr with xflags
459  * @fa:		fileattr pointer
460  * @xflags:	FS_XFLAG_* flags
461  *
462  * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags).  All
463  * other fields are zeroed.
464  */
fileattr_fill_xflags(struct fileattr * fa,u32 xflags)465 void fileattr_fill_xflags(struct fileattr *fa, u32 xflags)
466 {
467 	memset(fa, 0, sizeof(*fa));
468 	fa->fsx_valid = true;
469 	fa->fsx_xflags = xflags;
470 	if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE)
471 		fa->flags |= FS_IMMUTABLE_FL;
472 	if (fa->fsx_xflags & FS_XFLAG_APPEND)
473 		fa->flags |= FS_APPEND_FL;
474 	if (fa->fsx_xflags & FS_XFLAG_SYNC)
475 		fa->flags |= FS_SYNC_FL;
476 	if (fa->fsx_xflags & FS_XFLAG_NOATIME)
477 		fa->flags |= FS_NOATIME_FL;
478 	if (fa->fsx_xflags & FS_XFLAG_NODUMP)
479 		fa->flags |= FS_NODUMP_FL;
480 	if (fa->fsx_xflags & FS_XFLAG_DAX)
481 		fa->flags |= FS_DAX_FL;
482 	if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
483 		fa->flags |= FS_PROJINHERIT_FL;
484 }
485 EXPORT_SYMBOL(fileattr_fill_xflags);
486 
487 /**
488  * fileattr_fill_flags - initialize fileattr with flags
489  * @fa:		fileattr pointer
490  * @flags:	FS_*_FL flags
491  *
492  * Set ->flags, ->flags_valid and ->fsx_xflags (translated flags).
493  * All other fields are zeroed.
494  */
fileattr_fill_flags(struct fileattr * fa,u32 flags)495 void fileattr_fill_flags(struct fileattr *fa, u32 flags)
496 {
497 	memset(fa, 0, sizeof(*fa));
498 	fa->flags_valid = true;
499 	fa->flags = flags;
500 	if (fa->flags & FS_SYNC_FL)
501 		fa->fsx_xflags |= FS_XFLAG_SYNC;
502 	if (fa->flags & FS_IMMUTABLE_FL)
503 		fa->fsx_xflags |= FS_XFLAG_IMMUTABLE;
504 	if (fa->flags & FS_APPEND_FL)
505 		fa->fsx_xflags |= FS_XFLAG_APPEND;
506 	if (fa->flags & FS_NODUMP_FL)
507 		fa->fsx_xflags |= FS_XFLAG_NODUMP;
508 	if (fa->flags & FS_NOATIME_FL)
509 		fa->fsx_xflags |= FS_XFLAG_NOATIME;
510 	if (fa->flags & FS_DAX_FL)
511 		fa->fsx_xflags |= FS_XFLAG_DAX;
512 	if (fa->flags & FS_PROJINHERIT_FL)
513 		fa->fsx_xflags |= FS_XFLAG_PROJINHERIT;
514 }
515 EXPORT_SYMBOL(fileattr_fill_flags);
516 
517 /**
518  * vfs_fileattr_get - retrieve miscellaneous file attributes
519  * @dentry:	the object to retrieve from
520  * @fa:		fileattr pointer
521  *
522  * Call i_op->fileattr_get() callback, if exists.
523  *
524  * Return: 0 on success, or a negative error on failure.
525  */
vfs_fileattr_get(struct dentry * dentry,struct fileattr * fa)526 int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
527 {
528 	struct inode *inode = d_inode(dentry);
529 
530 	if (!inode->i_op->fileattr_get)
531 		return -ENOIOCTLCMD;
532 
533 	return inode->i_op->fileattr_get(dentry, fa);
534 }
535 EXPORT_SYMBOL(vfs_fileattr_get);
536 
537 /**
538  * copy_fsxattr_to_user - copy fsxattr to userspace.
539  * @fa:		fileattr pointer
540  * @ufa:	fsxattr user pointer
541  *
542  * Return: 0 on success, or -EFAULT on failure.
543  */
copy_fsxattr_to_user(const struct fileattr * fa,struct fsxattr __user * ufa)544 int copy_fsxattr_to_user(const struct fileattr *fa, struct fsxattr __user *ufa)
545 {
546 	struct fsxattr xfa;
547 
548 	memset(&xfa, 0, sizeof(xfa));
549 	xfa.fsx_xflags = fa->fsx_xflags;
550 	xfa.fsx_extsize = fa->fsx_extsize;
551 	xfa.fsx_nextents = fa->fsx_nextents;
552 	xfa.fsx_projid = fa->fsx_projid;
553 	xfa.fsx_cowextsize = fa->fsx_cowextsize;
554 
555 	if (copy_to_user(ufa, &xfa, sizeof(xfa)))
556 		return -EFAULT;
557 
558 	return 0;
559 }
560 EXPORT_SYMBOL(copy_fsxattr_to_user);
561 
copy_fsxattr_from_user(struct fileattr * fa,struct fsxattr __user * ufa)562 static int copy_fsxattr_from_user(struct fileattr *fa,
563 				  struct fsxattr __user *ufa)
564 {
565 	struct fsxattr xfa;
566 
567 	if (copy_from_user(&xfa, ufa, sizeof(xfa)))
568 		return -EFAULT;
569 
570 	fileattr_fill_xflags(fa, xfa.fsx_xflags);
571 	fa->fsx_extsize = xfa.fsx_extsize;
572 	fa->fsx_nextents = xfa.fsx_nextents;
573 	fa->fsx_projid = xfa.fsx_projid;
574 	fa->fsx_cowextsize = xfa.fsx_cowextsize;
575 
576 	return 0;
577 }
578 
579 /*
580  * Generic function to check FS_IOC_FSSETXATTR/FS_IOC_SETFLAGS values and reject
581  * any invalid configurations.
582  *
583  * Note: must be called with inode lock held.
584  */
fileattr_set_prepare(struct inode * inode,const struct fileattr * old_ma,struct fileattr * fa)585 static int fileattr_set_prepare(struct inode *inode,
586 			      const struct fileattr *old_ma,
587 			      struct fileattr *fa)
588 {
589 	int err;
590 
591 	/*
592 	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
593 	 * the relevant capability.
594 	 */
595 	if ((fa->flags ^ old_ma->flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL) &&
596 	    !capable(CAP_LINUX_IMMUTABLE))
597 		return -EPERM;
598 
599 	err = fscrypt_prepare_setflags(inode, old_ma->flags, fa->flags);
600 	if (err)
601 		return err;
602 
603 	/*
604 	 * Project Quota ID state is only allowed to change from within the init
605 	 * namespace. Enforce that restriction only if we are trying to change
606 	 * the quota ID state. Everything else is allowed in user namespaces.
607 	 */
608 	if (current_user_ns() != &init_user_ns) {
609 		if (old_ma->fsx_projid != fa->fsx_projid)
610 			return -EINVAL;
611 		if ((old_ma->fsx_xflags ^ fa->fsx_xflags) &
612 				FS_XFLAG_PROJINHERIT)
613 			return -EINVAL;
614 	} else {
615 		/*
616 		 * Caller is allowed to change the project ID. If it is being
617 		 * changed, make sure that the new value is valid.
618 		 */
619 		if (old_ma->fsx_projid != fa->fsx_projid &&
620 		    !projid_valid(make_kprojid(&init_user_ns, fa->fsx_projid)))
621 			return -EINVAL;
622 	}
623 
624 	/* Check extent size hints. */
625 	if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode))
626 		return -EINVAL;
627 
628 	if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) &&
629 			!S_ISDIR(inode->i_mode))
630 		return -EINVAL;
631 
632 	if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) &&
633 	    !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
634 		return -EINVAL;
635 
636 	/*
637 	 * It is only valid to set the DAX flag on regular files and
638 	 * directories on filesystems.
639 	 */
640 	if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
641 	    !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
642 		return -EINVAL;
643 
644 	/* Extent size hints of zero turn off the flags. */
645 	if (fa->fsx_extsize == 0)
646 		fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);
647 	if (fa->fsx_cowextsize == 0)
648 		fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE;
649 
650 	return 0;
651 }
652 
653 /**
654  * vfs_fileattr_set - change miscellaneous file attributes
655  * @idmap:	idmap of the mount
656  * @dentry:	the object to change
657  * @fa:		fileattr pointer
658  *
659  * After verifying permissions, call i_op->fileattr_set() callback, if
660  * exists.
661  *
662  * Verifying attributes involves retrieving current attributes with
663  * i_op->fileattr_get(), this also allows initializing attributes that have
664  * not been set by the caller to current values.  Inode lock is held
665  * thoughout to prevent racing with another instance.
666  *
667  * Return: 0 on success, or a negative error on failure.
668  */
vfs_fileattr_set(struct mnt_idmap * idmap,struct dentry * dentry,struct fileattr * fa)669 int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
670 		     struct fileattr *fa)
671 {
672 	struct inode *inode = d_inode(dentry);
673 	struct fileattr old_ma = {};
674 	int err;
675 
676 	if (!inode->i_op->fileattr_set)
677 		return -ENOIOCTLCMD;
678 
679 	if (!inode_owner_or_capable(idmap, inode))
680 		return -EPERM;
681 
682 	inode_lock(inode);
683 	err = vfs_fileattr_get(dentry, &old_ma);
684 	if (!err) {
685 		/* initialize missing bits from old_ma */
686 		if (fa->flags_valid) {
687 			fa->fsx_xflags |= old_ma.fsx_xflags & ~FS_XFLAG_COMMON;
688 			fa->fsx_extsize = old_ma.fsx_extsize;
689 			fa->fsx_nextents = old_ma.fsx_nextents;
690 			fa->fsx_projid = old_ma.fsx_projid;
691 			fa->fsx_cowextsize = old_ma.fsx_cowextsize;
692 		} else {
693 			fa->flags |= old_ma.flags & ~FS_COMMON_FL;
694 		}
695 		err = fileattr_set_prepare(inode, &old_ma, fa);
696 		if (!err)
697 			err = inode->i_op->fileattr_set(idmap, dentry, fa);
698 	}
699 	inode_unlock(inode);
700 
701 	return err;
702 }
703 EXPORT_SYMBOL(vfs_fileattr_set);
704 
ioctl_getflags(struct file * file,unsigned int __user * argp)705 static int ioctl_getflags(struct file *file, unsigned int __user *argp)
706 {
707 	struct fileattr fa = { .flags_valid = true }; /* hint only */
708 	int err;
709 
710 	err = vfs_fileattr_get(file->f_path.dentry, &fa);
711 	if (!err)
712 		err = put_user(fa.flags, argp);
713 	return err;
714 }
715 
ioctl_setflags(struct file * file,unsigned int __user * argp)716 static int ioctl_setflags(struct file *file, unsigned int __user *argp)
717 {
718 	struct mnt_idmap *idmap = file_mnt_idmap(file);
719 	struct dentry *dentry = file->f_path.dentry;
720 	struct fileattr fa;
721 	unsigned int flags;
722 	int err;
723 
724 	err = get_user(flags, argp);
725 	if (!err) {
726 		err = mnt_want_write_file(file);
727 		if (!err) {
728 			fileattr_fill_flags(&fa, flags);
729 			err = vfs_fileattr_set(idmap, dentry, &fa);
730 			mnt_drop_write_file(file);
731 		}
732 	}
733 	return err;
734 }
735 
ioctl_fsgetxattr(struct file * file,void __user * argp)736 static int ioctl_fsgetxattr(struct file *file, void __user *argp)
737 {
738 	struct fileattr fa = { .fsx_valid = true }; /* hint only */
739 	int err;
740 
741 	err = vfs_fileattr_get(file->f_path.dentry, &fa);
742 	if (!err)
743 		err = copy_fsxattr_to_user(&fa, argp);
744 
745 	return err;
746 }
747 
ioctl_fssetxattr(struct file * file,void __user * argp)748 static int ioctl_fssetxattr(struct file *file, void __user *argp)
749 {
750 	struct mnt_idmap *idmap = file_mnt_idmap(file);
751 	struct dentry *dentry = file->f_path.dentry;
752 	struct fileattr fa;
753 	int err;
754 
755 	err = copy_fsxattr_from_user(&fa, argp);
756 	if (!err) {
757 		err = mnt_want_write_file(file);
758 		if (!err) {
759 			err = vfs_fileattr_set(idmap, dentry, &fa);
760 			mnt_drop_write_file(file);
761 		}
762 	}
763 	return err;
764 }
765 
766 /*
767  * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
768  * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
769  *
770  * When you add any new common ioctls to the switches above and below,
771  * please ensure they have compatible arguments in compat mode.
772  */
do_vfs_ioctl(struct file * filp,unsigned int fd,unsigned int cmd,unsigned long arg)773 static int do_vfs_ioctl(struct file *filp, unsigned int fd,
774 			unsigned int cmd, unsigned long arg)
775 {
776 	void __user *argp = (void __user *)arg;
777 	struct inode *inode = file_inode(filp);
778 
779 	switch (cmd) {
780 	case FIOCLEX:
781 		set_close_on_exec(fd, 1);
782 		return 0;
783 
784 	case FIONCLEX:
785 		set_close_on_exec(fd, 0);
786 		return 0;
787 
788 	case FIONBIO:
789 		return ioctl_fionbio(filp, argp);
790 
791 	case FIOASYNC:
792 		return ioctl_fioasync(fd, filp, argp);
793 
794 	case FIOQSIZE:
795 		if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
796 		    S_ISLNK(inode->i_mode)) {
797 			loff_t res = inode_get_bytes(inode);
798 			return copy_to_user(argp, &res, sizeof(res)) ?
799 					    -EFAULT : 0;
800 		}
801 
802 		return -ENOTTY;
803 
804 	case FIFREEZE:
805 		return ioctl_fsfreeze(filp);
806 
807 	case FITHAW:
808 		return ioctl_fsthaw(filp);
809 
810 	case FS_IOC_FIEMAP:
811 		return ioctl_fiemap(filp, argp);
812 
813 	case FIGETBSZ:
814 		/* anon_bdev filesystems may not have a block size */
815 		if (!inode->i_sb->s_blocksize)
816 			return -EINVAL;
817 
818 		return put_user(inode->i_sb->s_blocksize, (int __user *)argp);
819 
820 	case FICLONE:
821 		return ioctl_file_clone(filp, arg, 0, 0, 0);
822 
823 	case FICLONERANGE:
824 		return ioctl_file_clone_range(filp, argp);
825 
826 	case FIDEDUPERANGE:
827 		return ioctl_file_dedupe_range(filp, argp);
828 
829 	case FIONREAD:
830 		if (!S_ISREG(inode->i_mode))
831 			return vfs_ioctl(filp, cmd, arg);
832 
833 		return put_user(i_size_read(inode) - filp->f_pos,
834 				(int __user *)argp);
835 
836 	case FS_IOC_GETFLAGS:
837 		return ioctl_getflags(filp, argp);
838 
839 	case FS_IOC_SETFLAGS:
840 		return ioctl_setflags(filp, argp);
841 
842 	case FS_IOC_FSGETXATTR:
843 		return ioctl_fsgetxattr(filp, argp);
844 
845 	case FS_IOC_FSSETXATTR:
846 		return ioctl_fssetxattr(filp, argp);
847 
848 	default:
849 		if (S_ISREG(inode->i_mode))
850 			return file_ioctl(filp, cmd, argp);
851 		break;
852 	}
853 
854 	return -ENOIOCTLCMD;
855 }
856 
SYSCALL_DEFINE3(ioctl,unsigned int,fd,unsigned int,cmd,unsigned long,arg)857 SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
858 {
859 	struct fd f = fdget(fd);
860 	int error;
861 
862 	if (!f.file)
863 		return -EBADF;
864 
865 	error = security_file_ioctl(f.file, cmd, arg);
866 	if (error)
867 		goto out;
868 
869 	error = do_vfs_ioctl(f.file, fd, cmd, arg);
870 	if (error == -ENOIOCTLCMD)
871 		error = vfs_ioctl(f.file, cmd, arg);
872 
873 out:
874 	fdput(f);
875 	return error;
876 }
877 
878 #ifdef CONFIG_COMPAT
879 /**
880  * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
881  * @file: The file to operate on.
882  * @cmd: The ioctl command number.
883  * @arg: The argument to the ioctl.
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  */
compat_ptr_ioctl(struct file * file,unsigned int cmd,unsigned long arg)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 
COMPAT_SYSCALL_DEFINE3(ioctl,unsigned int,fd,unsigned int,cmd,compat_ulong_t,arg)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 	error = security_file_ioctl_compat(f.file, cmd, arg);
924 	if (error)
925 		goto out;
926 
927 	switch (cmd) {
928 	/* FICLONE takes an int argument, so don't use compat_ptr() */
929 	case FICLONE:
930 		error = ioctl_file_clone(f.file, arg, 0, 0, 0);
931 		break;
932 
933 #if defined(CONFIG_X86_64)
934 	/* these get messy on amd64 due to alignment differences */
935 	case FS_IOC_RESVSP_32:
936 	case FS_IOC_RESVSP64_32:
937 		error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg));
938 		break;
939 	case FS_IOC_UNRESVSP_32:
940 	case FS_IOC_UNRESVSP64_32:
941 		error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE,
942 				compat_ptr(arg));
943 		break;
944 	case FS_IOC_ZERO_RANGE_32:
945 		error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE,
946 				compat_ptr(arg));
947 		break;
948 #endif
949 
950 	/*
951 	 * These access 32-bit values anyway so no further handling is
952 	 * necessary.
953 	 */
954 	case FS_IOC32_GETFLAGS:
955 	case FS_IOC32_SETFLAGS:
956 		cmd = (cmd == FS_IOC32_GETFLAGS) ?
957 			FS_IOC_GETFLAGS : FS_IOC_SETFLAGS;
958 		fallthrough;
959 	/*
960 	 * everything else in do_vfs_ioctl() takes either a compatible
961 	 * pointer argument or no argument -- call it with a modified
962 	 * argument.
963 	 */
964 	default:
965 		error = do_vfs_ioctl(f.file, fd, cmd,
966 				     (unsigned long)compat_ptr(arg));
967 		if (error != -ENOIOCTLCMD)
968 			break;
969 
970 		if (f.file->f_op->compat_ioctl)
971 			error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
972 		if (error == -ENOIOCTLCMD)
973 			error = -ENOTTY;
974 		break;
975 	}
976 
977  out:
978 	fdput(f);
979 
980 	return error;
981 }
982 #endif
983