xref: /linux/fs/ioctl.c (revision 3fd6c59042dbba50391e30862beac979491145fe)
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 	CLASS(fd, src_file)(srcfd);
235 	loff_t cloned;
236 	int ret;
237 
238 	if (fd_empty(src_file))
239 		return -EBADF;
240 	cloned = vfs_clone_file_range(fd_file(src_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 	return ret;
249 }
250 
ioctl_file_clone_range(struct file * file,struct file_clone_range __user * argp)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  */
ioctl_preallocate(struct file * filp,int mode,void __user * argp)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 */
compat_ioctl_preallocate(struct file * file,int mode,struct space_resv_32 __user * argp)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 
file_ioctl(struct file * filp,unsigned int cmd,int __user * p)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 
ioctl_fionbio(struct file * filp,int __user * argp)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 
ioctl_fioasync(unsigned int fd,struct file * filp,int __user * argp)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 
ioctl_fsfreeze(struct file * filp)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, FREEZE_HOLDER_USERSPACE);
400 	return freeze_super(sb, FREEZE_HOLDER_USERSPACE);
401 }
402 
ioctl_fsthaw(struct file * filp)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, FREEZE_HOLDER_USERSPACE);
413 	return thaw_super(sb, FREEZE_HOLDER_USERSPACE);
414 }
415 
ioctl_file_dedupe_range(struct file * file,struct file_dedupe_range __user * argp)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  */
fileattr_fill_xflags(struct fileattr * fa,u32 xflags)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  */
fileattr_fill_flags(struct fileattr * fa,u32 flags)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  */
vfs_fileattr_get(struct dentry * dentry,struct fileattr * fa)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  */
copy_fsxattr_to_user(const struct fileattr * fa,struct fsxattr __user * ufa)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 
copy_fsxattr_from_user(struct fileattr * fa,struct fsxattr __user * ufa)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  */
fileattr_set_prepare(struct inode * inode,const struct fileattr * old_ma,struct fileattr * fa)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  * @idmap:	idmap 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  */
vfs_fileattr_set(struct mnt_idmap * idmap,struct dentry * dentry,struct fileattr * fa)668 int vfs_fileattr_set(struct mnt_idmap *idmap, 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(idmap, 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(idmap, dentry, fa);
697 	}
698 	inode_unlock(inode);
699 
700 	return err;
701 }
702 EXPORT_SYMBOL(vfs_fileattr_set);
703 
ioctl_getflags(struct file * file,unsigned int __user * argp)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 
ioctl_setflags(struct file * file,unsigned int __user * argp)715 static int ioctl_setflags(struct file *file, unsigned int __user *argp)
716 {
717 	struct mnt_idmap *idmap = file_mnt_idmap(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(idmap, dentry, &fa);
729 			mnt_drop_write_file(file);
730 		}
731 	}
732 	return err;
733 }
734 
ioctl_fsgetxattr(struct file * file,void __user * argp)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 
ioctl_fssetxattr(struct file * file,void __user * argp)747 static int ioctl_fssetxattr(struct file *file, void __user *argp)
748 {
749 	struct mnt_idmap *idmap = file_mnt_idmap(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(idmap, dentry, &fa);
759 			mnt_drop_write_file(file);
760 		}
761 	}
762 	return err;
763 }
764 
ioctl_getfsuuid(struct file * file,void __user * argp)765 static int ioctl_getfsuuid(struct file *file, void __user *argp)
766 {
767 	struct super_block *sb = file_inode(file)->i_sb;
768 	struct fsuuid2 u = { .len = sb->s_uuid_len, };
769 
770 	if (!sb->s_uuid_len)
771 		return -ENOTTY;
772 
773 	memcpy(&u.uuid[0], &sb->s_uuid, sb->s_uuid_len);
774 
775 	return copy_to_user(argp, &u, sizeof(u)) ? -EFAULT : 0;
776 }
777 
ioctl_get_fs_sysfs_path(struct file * file,void __user * argp)778 static int ioctl_get_fs_sysfs_path(struct file *file, void __user *argp)
779 {
780 	struct super_block *sb = file_inode(file)->i_sb;
781 
782 	if (!strlen(sb->s_sysfs_name))
783 		return -ENOTTY;
784 
785 	struct fs_sysfs_path u = {};
786 
787 	u.len = scnprintf(u.name, sizeof(u.name), "%s/%s", sb->s_type->name, sb->s_sysfs_name);
788 
789 	return copy_to_user(argp, &u, sizeof(u)) ? -EFAULT : 0;
790 }
791 
792 /*
793  * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
794  * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
795  *
796  * When you add any new common ioctls to the switches above and below,
797  * please ensure they have compatible arguments in compat mode.
798  *
799  * The LSM mailing list should also be notified of any command additions or
800  * changes, as specific LSMs may be affected.
801  */
do_vfs_ioctl(struct file * filp,unsigned int fd,unsigned int cmd,unsigned long arg)802 static int do_vfs_ioctl(struct file *filp, unsigned int fd,
803 			unsigned int cmd, unsigned long arg)
804 {
805 	void __user *argp = (void __user *)arg;
806 	struct inode *inode = file_inode(filp);
807 
808 	switch (cmd) {
809 	case FIOCLEX:
810 		set_close_on_exec(fd, 1);
811 		return 0;
812 
813 	case FIONCLEX:
814 		set_close_on_exec(fd, 0);
815 		return 0;
816 
817 	case FIONBIO:
818 		return ioctl_fionbio(filp, argp);
819 
820 	case FIOASYNC:
821 		return ioctl_fioasync(fd, filp, argp);
822 
823 	case FIOQSIZE:
824 		if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
825 		    S_ISLNK(inode->i_mode)) {
826 			loff_t res = inode_get_bytes(inode);
827 			return copy_to_user(argp, &res, sizeof(res)) ?
828 					    -EFAULT : 0;
829 		}
830 
831 		return -ENOTTY;
832 
833 	case FIFREEZE:
834 		return ioctl_fsfreeze(filp);
835 
836 	case FITHAW:
837 		return ioctl_fsthaw(filp);
838 
839 	case FS_IOC_FIEMAP:
840 		return ioctl_fiemap(filp, argp);
841 
842 	case FIGETBSZ:
843 		/* anon_bdev filesystems may not have a block size */
844 		if (!inode->i_sb->s_blocksize)
845 			return -EINVAL;
846 
847 		return put_user(inode->i_sb->s_blocksize, (int __user *)argp);
848 
849 	case FICLONE:
850 		return ioctl_file_clone(filp, arg, 0, 0, 0);
851 
852 	case FICLONERANGE:
853 		return ioctl_file_clone_range(filp, argp);
854 
855 	case FIDEDUPERANGE:
856 		return ioctl_file_dedupe_range(filp, argp);
857 
858 	case FIONREAD:
859 		if (!S_ISREG(inode->i_mode))
860 			return vfs_ioctl(filp, cmd, arg);
861 
862 		return put_user(i_size_read(inode) - filp->f_pos,
863 				(int __user *)argp);
864 
865 	case FS_IOC_GETFLAGS:
866 		return ioctl_getflags(filp, argp);
867 
868 	case FS_IOC_SETFLAGS:
869 		return ioctl_setflags(filp, argp);
870 
871 	case FS_IOC_FSGETXATTR:
872 		return ioctl_fsgetxattr(filp, argp);
873 
874 	case FS_IOC_FSSETXATTR:
875 		return ioctl_fssetxattr(filp, argp);
876 
877 	case FS_IOC_GETFSUUID:
878 		return ioctl_getfsuuid(filp, argp);
879 
880 	case FS_IOC_GETFSSYSFSPATH:
881 		return ioctl_get_fs_sysfs_path(filp, argp);
882 
883 	default:
884 		if (S_ISREG(inode->i_mode))
885 			return file_ioctl(filp, cmd, argp);
886 		break;
887 	}
888 
889 	return -ENOIOCTLCMD;
890 }
891 
SYSCALL_DEFINE3(ioctl,unsigned int,fd,unsigned int,cmd,unsigned long,arg)892 SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
893 {
894 	CLASS(fd, f)(fd);
895 	int error;
896 
897 	if (fd_empty(f))
898 		return -EBADF;
899 
900 	error = security_file_ioctl(fd_file(f), cmd, arg);
901 	if (error)
902 		return error;
903 
904 	error = do_vfs_ioctl(fd_file(f), fd, cmd, arg);
905 	if (error == -ENOIOCTLCMD)
906 		error = vfs_ioctl(fd_file(f), cmd, arg);
907 
908 	return error;
909 }
910 
911 #ifdef CONFIG_COMPAT
912 /**
913  * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
914  * @file: The file to operate on.
915  * @cmd: The ioctl command number.
916  * @arg: The argument to the ioctl.
917  *
918  * This is not normally called as a function, but instead set in struct
919  * file_operations as
920  *
921  *     .compat_ioctl = compat_ptr_ioctl,
922  *
923  * On most architectures, the compat_ptr_ioctl() just passes all arguments
924  * to the corresponding ->ioctl handler. The exception is arch/s390, where
925  * compat_ptr() clears the top bit of a 32-bit pointer value, so user space
926  * pointers to the second 2GB alias the first 2GB, as is the case for
927  * native 32-bit s390 user space.
928  *
929  * The compat_ptr_ioctl() function must therefore be used only with ioctl
930  * functions that either ignore the argument or pass a pointer to a
931  * compatible data type.
932  *
933  * If any ioctl command handled by fops->unlocked_ioctl passes a plain
934  * integer instead of a pointer, or any of the passed data types
935  * is incompatible between 32-bit and 64-bit architectures, a proper
936  * handler is required instead of compat_ptr_ioctl.
937  */
compat_ptr_ioctl(struct file * file,unsigned int cmd,unsigned long arg)938 long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
939 {
940 	if (!file->f_op->unlocked_ioctl)
941 		return -ENOIOCTLCMD;
942 
943 	return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
944 }
945 EXPORT_SYMBOL(compat_ptr_ioctl);
946 
COMPAT_SYSCALL_DEFINE3(ioctl,unsigned int,fd,unsigned int,cmd,compat_ulong_t,arg)947 COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
948 		       compat_ulong_t, arg)
949 {
950 	CLASS(fd, f)(fd);
951 	int error;
952 
953 	if (fd_empty(f))
954 		return -EBADF;
955 
956 	error = security_file_ioctl_compat(fd_file(f), cmd, arg);
957 	if (error)
958 		return error;
959 
960 	switch (cmd) {
961 	/* FICLONE takes an int argument, so don't use compat_ptr() */
962 	case FICLONE:
963 		error = ioctl_file_clone(fd_file(f), arg, 0, 0, 0);
964 		break;
965 
966 #if defined(CONFIG_X86_64)
967 	/* these get messy on amd64 due to alignment differences */
968 	case FS_IOC_RESVSP_32:
969 	case FS_IOC_RESVSP64_32:
970 		error = compat_ioctl_preallocate(fd_file(f), 0, compat_ptr(arg));
971 		break;
972 	case FS_IOC_UNRESVSP_32:
973 	case FS_IOC_UNRESVSP64_32:
974 		error = compat_ioctl_preallocate(fd_file(f), FALLOC_FL_PUNCH_HOLE,
975 				compat_ptr(arg));
976 		break;
977 	case FS_IOC_ZERO_RANGE_32:
978 		error = compat_ioctl_preallocate(fd_file(f), FALLOC_FL_ZERO_RANGE,
979 				compat_ptr(arg));
980 		break;
981 #endif
982 
983 	/*
984 	 * These access 32-bit values anyway so no further handling is
985 	 * necessary.
986 	 */
987 	case FS_IOC32_GETFLAGS:
988 	case FS_IOC32_SETFLAGS:
989 		cmd = (cmd == FS_IOC32_GETFLAGS) ?
990 			FS_IOC_GETFLAGS : FS_IOC_SETFLAGS;
991 		fallthrough;
992 	/*
993 	 * everything else in do_vfs_ioctl() takes either a compatible
994 	 * pointer argument or no argument -- call it with a modified
995 	 * argument.
996 	 */
997 	default:
998 		error = do_vfs_ioctl(fd_file(f), fd, cmd,
999 				     (unsigned long)compat_ptr(arg));
1000 		if (error != -ENOIOCTLCMD)
1001 			break;
1002 
1003 		if (fd_file(f)->f_op->compat_ioctl)
1004 			error = fd_file(f)->f_op->compat_ioctl(fd_file(f), cmd, arg);
1005 		if (error == -ENOIOCTLCMD)
1006 			error = -ENOTTY;
1007 		break;
1008 	}
1009 	return error;
1010 }
1011 #endif
1012