[linux.git] / fs / attr.c

/*
 *  linux/fs/attr.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  changes by Thomas Schoebel-Theuer
 */

#include <linux/export.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/sched/signal.h>
#include <linux/capability.h>
#include <linux/fsnotify.h>
#include <linux/fcntl.h>
#include <linux/security.h>
#include <linux/evm.h>
#include <linux/ima.h>

/**
 * setattr_prepare - check if attribute changes to a dentry are allowed
 * @dentry:	dentry to check
 * @attr:	attributes to change
 *
 * Check if we are allowed to change the attributes contained in @attr
 * in the given dentry.  This includes the normal unix access permission
 * checks, as well as checks for rlimits and others. The function also clears
 * SGID bit from mode if user is not allowed to set it. Also file capabilities
 * and IMA extended attributes are cleared if ATTR_KILL_PRIV is set.
 *
 * Should be called as the first thing in ->setattr implementations,
 * possibly after taking additional locks.
 */
int setattr_prepare(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = d_inode(dentry);
	unsigned int ia_valid = attr->ia_valid;

	/*
	 * First check size constraints.  These can't be overriden using
	 * ATTR_FORCE.
	 */
	if (ia_valid & ATTR_SIZE) {
		int error = inode_newsize_ok(inode, attr->ia_size);
		if (error)
			return error;
	}

	/* If force is set do it anyway. */
	if (ia_valid & ATTR_FORCE)
		goto kill_priv;

	/* Make sure a caller can chown. */
	if ((ia_valid & ATTR_UID) &&
	    (!uid_eq(current_fsuid(), inode->i_uid) ||
	     !uid_eq(attr->ia_uid, inode->i_uid)) &&
	    !capable_wrt_inode_uidgid(inode, CAP_CHOWN))
		return -EPERM;

	/* Make sure caller can chgrp. */
	if ((ia_valid & ATTR_GID) &&
	    (!uid_eq(current_fsuid(), inode->i_uid) ||
	    (!in_group_p(attr->ia_gid) && !gid_eq(attr->ia_gid, inode->i_gid))) &&
	    !capable_wrt_inode_uidgid(inode, CAP_CHOWN))
		return -EPERM;

	/* Make sure a caller can chmod. */
	if (ia_valid & ATTR_MODE) {
		if (!inode_owner_or_capable(inode))
			return -EPERM;
		/* Also check the setgid bit! */
		if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
				inode->i_gid) &&
		    !capable_wrt_inode_uidgid(inode, CAP_FSETID))
			attr->ia_mode &= ~S_ISGID;
	}

	/* Check for setting the inode time. */
	if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
		if (!inode_owner_or_capable(inode))
			return -EPERM;
	}

kill_priv:
	/* User has permission for the change */
	if (ia_valid & ATTR_KILL_PRIV) {
		int error;

		error = security_inode_killpriv(dentry);
		if (error)
			return error;
	}

	return 0;
}
EXPORT_SYMBOL(setattr_prepare);

/**
 * inode_newsize_ok - may this inode be truncated to a given size
 * @inode:	the inode to be truncated
 * @offset:	the new size to assign to the inode
 * @Returns:	0 on success, -ve errno on failure
 *
 * inode_newsize_ok must be called with i_mutex held.
 *
 * inode_newsize_ok will check filesystem limits and ulimits to check that the
 * new inode size is within limits. inode_newsize_ok will also send SIGXFSZ
 * when necessary. Caller must not proceed with inode size change if failure is
 * returned. @inode must be a file (not directory), with appropriate
 * permissions to allow truncate (inode_newsize_ok does NOT check these
 * conditions).
 */
int inode_newsize_ok(const struct inode *inode, loff_t offset)
{
	if (inode->i_size < offset) {
		unsigned long limit;

		limit = rlimit(RLIMIT_FSIZE);
		if (limit != RLIM_INFINITY && offset > limit)
			goto out_sig;
		if (offset > inode->i_sb->s_maxbytes)
			goto out_big;
	} else {
		/*
		 * truncation of in-use swapfiles is disallowed - it would
		 * cause subsequent swapout to scribble on the now-freed
		 * blocks.
		 */
		if (IS_SWAPFILE(inode))
			return -ETXTBSY;
	}

	return 0;
out_sig:
	send_sig(SIGXFSZ, current, 0);
out_big:
	return -EFBIG;
}
EXPORT_SYMBOL(inode_newsize_ok);

/**
 * setattr_copy - copy simple metadata updates into the generic inode
 * @inode:	the inode to be updated
 * @attr:	the new attributes
 *
 * setattr_copy must be called with i_mutex held.
 *
 * setattr_copy updates the inode's metadata with that specified
 * in attr. Noticeably missing is inode size update, which is more complex
 * as it requires pagecache updates.
 *
 * The inode is not marked as dirty after this operation. The rationale is
 * that for "simple" filesystems, the struct inode is the inode storage.
 * The caller is free to mark the inode dirty afterwards if needed.
 */
void setattr_copy(struct inode *inode, const struct iattr *attr)
{
	unsigned int ia_valid = attr->ia_valid;

	if (ia_valid & ATTR_UID)
		inode->i_uid = attr->ia_uid;
	if (ia_valid & ATTR_GID)
		inode->i_gid = attr->ia_gid;
	if (ia_valid & ATTR_ATIME)
		inode->i_atime = timespec_trunc(attr->ia_atime,
						inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_MTIME)
		inode->i_mtime = timespec_trunc(attr->ia_mtime,
						inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_CTIME)
		inode->i_ctime = timespec_trunc(attr->ia_ctime,
						inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_MODE) {
		umode_t mode = attr->ia_mode;

		if (!in_group_p(inode->i_gid) &&
		    !capable_wrt_inode_uidgid(inode, CAP_FSETID))
			mode &= ~S_ISGID;
		inode->i_mode = mode;
	}
}
EXPORT_SYMBOL(setattr_copy);

/**
 * notify_change - modify attributes of a filesytem object
 * @dentry:	object affected
 * @iattr:	new attributes
 * @delegated_inode: returns inode, if the inode is delegated
 *
 * The caller must hold the i_mutex on the affected object.
 *
 * If notify_change discovers a delegation in need of breaking,
 * it will return -EWOULDBLOCK and return a reference to the inode in
 * delegated_inode.  The caller should then break the delegation and
 * retry.  Because breaking a delegation may take a long time, the
 * caller should drop the i_mutex before doing so.
 *
 * Alternatively, a caller may pass NULL for delegated_inode.  This may
 * be appropriate for callers that expect the underlying filesystem not
 * to be NFS exported.  Also, passing NULL is fine for callers holding
 * the file open for write, as there can be no conflicting delegation in
 * that case.
 */
int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
{
	struct inode *inode = dentry->d_inode;
	umode_t mode = inode->i_mode;
	int error;
	struct timespec now;
	unsigned int ia_valid = attr->ia_valid;

	WARN_ON_ONCE(!inode_is_locked(inode));

	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {
		if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
			return -EPERM;
	}

	/*
	 * If utimes(2) and friends are called with times == NULL (or both
	 * times are UTIME_NOW), then we need to check for write permission
	 */
	if (ia_valid & ATTR_TOUCH) {
		if (IS_IMMUTABLE(inode))
			return -EPERM;

		if (!inode_owner_or_capable(inode)) {
			error = inode_permission(inode, MAY_WRITE);
			if (error)
				return error;
		}
	}

	if ((ia_valid & ATTR_MODE)) {
		umode_t amode = attr->ia_mode;
		/* Flag setting protected by i_mutex */
		if (is_sxid(amode))
			inode->i_flags &= ~S_NOSEC;
	}

	now = current_time(inode);

	attr->ia_ctime = now;
	if (!(ia_valid & ATTR_ATIME_SET))
		attr->ia_atime = now;
	if (!(ia_valid & ATTR_MTIME_SET))
		attr->ia_mtime = now;
	if (ia_valid & ATTR_KILL_PRIV) {
		error = security_inode_need_killpriv(dentry);
		if (error < 0)
			return error;
		if (error == 0)
			ia_valid = attr->ia_valid &= ~ATTR_KILL_PRIV;
	}

	/*
	 * We now pass ATTR_KILL_S*ID to the lower level setattr function so
	 * that the function has the ability to reinterpret a mode change
	 * that's due to these bits. This adds an implicit restriction that
	 * no function will ever call notify_change with both ATTR_MODE and
	 * ATTR_KILL_S*ID set.
	 */
	if ((ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) &&
	    (ia_valid & ATTR_MODE))
		BUG();

	if (ia_valid & ATTR_KILL_SUID) {
		if (mode & S_ISUID) {
			ia_valid = attr->ia_valid |= ATTR_MODE;
			attr->ia_mode = (inode->i_mode & ~S_ISUID);
		}
	}
	if (ia_valid & ATTR_KILL_SGID) {
		if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
			if (!(ia_valid & ATTR_MODE)) {
				ia_valid = attr->ia_valid |= ATTR_MODE;
				attr->ia_mode = inode->i_mode;
			}
			attr->ia_mode &= ~S_ISGID;
		}
	}
	if (!(attr->ia_valid & ~(ATTR_KILL_SUID | ATTR_KILL_SGID)))
		return 0;

	/*
	 * Verify that uid/gid changes are valid in the target
	 * namespace of the superblock.
	 */
	if (ia_valid & ATTR_UID &&
	    !kuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid))
		return -EOVERFLOW;
	if (ia_valid & ATTR_GID &&
	    !kgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid))
		return -EOVERFLOW;

	/* Don't allow modifications of files with invalid uids or
	 * gids unless those uids & gids are being made valid.
	 */
	if (!(ia_valid & ATTR_UID) && !uid_valid(inode->i_uid))
		return -EOVERFLOW;
	if (!(ia_valid & ATTR_GID) && !gid_valid(inode->i_gid))
		return -EOVERFLOW;

	error = security_inode_setattr(dentry, attr);
	if (error)
		return error;
	error = try_break_deleg(inode, delegated_inode);
	if (error)
		return error;

	if (inode->i_op->setattr)
		error = inode->i_op->setattr(dentry, attr);
	else
		error = simple_setattr(dentry, attr);

	if (!error) {
		fsnotify_change(dentry, ia_valid);
		ima_inode_post_setattr(dentry);
		evm_inode_post_setattr(dentry, ia_valid);
	}

	return error;
}
EXPORT_SYMBOL(notify_change);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/attr.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	* changes by Thomas Schoebel-Theuer
	6	*/
	7
630d9c47	8	#include <linux/export.h>
1da177e4 LT	9	#include <linux/time.h>
	10	#include <linux/mm.h>
	11	#include <linux/string.h>
3f07c014	12	#include <linux/sched/signal.h>
16f7e0fe	13	#include <linux/capability.h>
0eeca283	14	#include <linux/fsnotify.h>
1da177e4	15	#include <linux/fcntl.h>
1da177e4	16	#include <linux/security.h>
975d2943	17	#include <linux/evm.h>
9957a504	18	#include <linux/ima.h>
1da177e4	19
2c27c65e	20	/**
31051c85 JK	21	* setattr_prepare - check if attribute changes to a dentry are allowed
31051c85 JK	22	* @dentry: dentry to check
2c27c65e CH	23	* @attr: attributes to change
	24	*
	25	* Check if we are allowed to change the attributes contained in @attr
31051c85 JK	26	* in the given dentry. This includes the normal unix access permission
	27	* checks, as well as checks for rlimits and others. The function also clears
	28	* SGID bit from mode if user is not allowed to set it. Also file capabilities
	29	* and IMA extended attributes are cleared if ATTR_KILL_PRIV is set.
2c27c65e CH	30	*
	31	* Should be called as the first thing in ->setattr implementations,
	32	* possibly after taking additional locks.
	33	*/
31051c85	34	int setattr_prepare(struct dentry dentry, struct iattr attr)
1da177e4	35	{
31051c85	36	struct inode *inode = d_inode(dentry);
1da177e4 LT	37	unsigned int ia_valid = attr->ia_valid;
1da177e4 LT	38
2c27c65e CH	39	/*
	40	* First check size constraints. These can't be overriden using
	41	* ATTR_FORCE.
	42	*/
	43	if (ia_valid & ATTR_SIZE) {
	44	int error = inode_newsize_ok(inode, attr->ia_size);
	45	if (error)
	46	return error;
	47	}
	48
1da177e4 LT	49	/* If force is set do it anyway. */
1da177e4 LT	50	if (ia_valid & ATTR_FORCE)
030b533c	51	goto kill_priv;
1da177e4 LT	52
	53	/* Make sure a caller can chown. */
	54	if ((ia_valid & ATTR_UID) &&
8e96e3b7	55	(!uid_eq(current_fsuid(), inode->i_uid) \|\|
7fa294c8	56	!uid_eq(attr->ia_uid, inode->i_uid)) &&
23adbe12	57	!capable_wrt_inode_uidgid(inode, CAP_CHOWN))
2c27c65e	58	return -EPERM;
1da177e4 LT	59
	60	/* Make sure caller can chgrp. */
	61	if ((ia_valid & ATTR_GID) &&
8e96e3b7 EB	62	(!uid_eq(current_fsuid(), inode->i_uid) \|\|
8e96e3b7 EB	63	(!in_group_p(attr->ia_gid) && !gid_eq(attr->ia_gid, inode->i_gid))) &&
23adbe12	64	!capable_wrt_inode_uidgid(inode, CAP_CHOWN))
2c27c65e	65	return -EPERM;
1da177e4 LT	66
	67	/* Make sure a caller can chmod. */
	68	if (ia_valid & ATTR_MODE) {
2e149670	69	if (!inode_owner_or_capable(inode))
2c27c65e	70	return -EPERM;
1da177e4 LT	71	/* Also check the setgid bit! */
1da177e4 LT	72	if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
7fa294c8	73	inode->i_gid) &&
23adbe12	74	!capable_wrt_inode_uidgid(inode, CAP_FSETID))
1da177e4 LT	75	attr->ia_mode &= ~S_ISGID;
	76	}
	77
	78	/* Check for setting the inode time. */
9767d749	79	if (ia_valid & (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)) {
2e149670	80	if (!inode_owner_or_capable(inode))
2c27c65e	81	return -EPERM;
1da177e4	82	}
2c27c65e	83
030b533c JK	84	kill_priv:
	85	/* User has permission for the change */
	86	if (ia_valid & ATTR_KILL_PRIV) {
	87	int error;
	88
	89	error = security_inode_killpriv(dentry);
	90	if (error)
	91	return error;
	92	}
	93
2c27c65e	94	return 0;
1da177e4	95	}
31051c85	96	EXPORT_SYMBOL(setattr_prepare);
1da177e4	97
25d9e2d1 NP	98	/**
	99	* inode_newsize_ok - may this inode be truncated to a given size
	100	* @inode: the inode to be truncated
	101	* @offset: the new size to assign to the inode
	102	* @Returns: 0 on success, -ve errno on failure
	103	*
7bb46a67 NP	104	* inode_newsize_ok must be called with i_mutex held.
7bb46a67 NP	105	*
25d9e2d1 NP	106	* inode_newsize_ok will check filesystem limits and ulimits to check that the
	107	* new inode size is within limits. inode_newsize_ok will also send SIGXFSZ
	108	* when necessary. Caller must not proceed with inode size change if failure is
	109	* returned. @inode must be a file (not directory), with appropriate
	110	* permissions to allow truncate (inode_newsize_ok does NOT check these
	111	* conditions).
25d9e2d1 NP	112	*/
	113	int inode_newsize_ok(const struct inode *inode, loff_t offset)
	114	{
	115	if (inode->i_size < offset) {
	116	unsigned long limit;
	117
d554ed89	118	limit = rlimit(RLIMIT_FSIZE);
25d9e2d1 NP	119	if (limit != RLIM_INFINITY && offset > limit)
	120	goto out_sig;
	121	if (offset > inode->i_sb->s_maxbytes)
	122	goto out_big;
	123	} else {
	124	/*
	125	* truncation of in-use swapfiles is disallowed - it would
	126	* cause subsequent swapout to scribble on the now-freed
	127	* blocks.
	128	*/
	129	if (IS_SWAPFILE(inode))
	130	return -ETXTBSY;
	131	}
	132
	133	return 0;
	134	out_sig:
	135	send_sig(SIGXFSZ, current, 0);
	136	out_big:
	137	return -EFBIG;
	138	}
	139	EXPORT_SYMBOL(inode_newsize_ok);
	140
7bb46a67	141	/**
6a1a90ad	142	* setattr_copy - copy simple metadata updates into the generic inode
7bb46a67 NP	143	* @inode: the inode to be updated
	144	* @attr: the new attributes
	145	*
6a1a90ad	146	* setattr_copy must be called with i_mutex held.
7bb46a67	147	*
6a1a90ad	148	* setattr_copy updates the inode's metadata with that specified
25985edc	149	* in attr. Noticeably missing is inode size update, which is more complex
2c27c65e	150	* as it requires pagecache updates.
7bb46a67 NP	151	*
	152	* The inode is not marked as dirty after this operation. The rationale is
	153	* that for "simple" filesystems, the struct inode is the inode storage.
	154	* The caller is free to mark the inode dirty afterwards if needed.
	155	*/
6a1a90ad	156	void setattr_copy(struct inode inode, const struct iattr attr)
1da177e4 LT	157	{
1da177e4 LT	158	unsigned int ia_valid = attr->ia_valid;
4a30131e	159
1da177e4 LT	160	if (ia_valid & ATTR_UID)
	161	inode->i_uid = attr->ia_uid;
	162	if (ia_valid & ATTR_GID)
	163	inode->i_gid = attr->ia_gid;
	164	if (ia_valid & ATTR_ATIME)
	165	inode->i_atime = timespec_trunc(attr->ia_atime,
	166	inode->i_sb->s_time_gran);
	167	if (ia_valid & ATTR_MTIME)
	168	inode->i_mtime = timespec_trunc(attr->ia_mtime,
	169	inode->i_sb->s_time_gran);
	170	if (ia_valid & ATTR_CTIME)
	171	inode->i_ctime = timespec_trunc(attr->ia_ctime,
	172	inode->i_sb->s_time_gran);
	173	if (ia_valid & ATTR_MODE) {
	174	umode_t mode = attr->ia_mode;
	175
7fa294c8	176	if (!in_group_p(inode->i_gid) &&
23adbe12	177	!capable_wrt_inode_uidgid(inode, CAP_FSETID))
1da177e4 LT	178	mode &= ~S_ISGID;
	179	inode->i_mode = mode;
	180	}
7bb46a67	181	}
6a1a90ad	182	EXPORT_SYMBOL(setattr_copy);
7bb46a67	183
27ac0ffe BF	184	/**
	185	* notify_change - modify attributes of a filesytem object
	186	* @dentry: object affected
	187	* @iattr: new attributes
	188	* @delegated_inode: returns inode, if the inode is delegated
	189	*
	190	* The caller must hold the i_mutex on the affected object.
	191	*
	192	* If notify_change discovers a delegation in need of breaking,
	193	* it will return -EWOULDBLOCK and return a reference to the inode in
	194	* delegated_inode. The caller should then break the delegation and
	195	* retry. Because breaking a delegation may take a long time, the
	196	* caller should drop the i_mutex before doing so.
	197	*
	198	* Alternatively, a caller may pass NULL for delegated_inode. This may
	199	* be appropriate for callers that expect the underlying filesystem not
	200	* to be NFS exported. Also, passing NULL is fine for callers holding
	201	* the file open for write, as there can be no conflicting delegation in
	202	* that case.
	203	*/
	204	int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
1da177e4 LT	205	{
1da177e4 LT	206	struct inode *inode = dentry->d_inode;
8d334acd	207	umode_t mode = inode->i_mode;
1da177e4 LT	208	int error;
	209	struct timespec now;
	210	unsigned int ia_valid = attr->ia_valid;
	211
5955102c	212	WARN_ON_ONCE(!inode_is_locked(inode));
c4107b30	213
beb29e05 MS	214	if (ia_valid & (ATTR_MODE \| ATTR_UID \| ATTR_GID \| ATTR_TIMES_SET)) {
	215	if (IS_IMMUTABLE(inode) \|\| IS_APPEND(inode))
	216	return -EPERM;
	217	}
	218
f2b20f6e MS	219	/*
	220	* If utimes(2) and friends are called with times == NULL (or both
	221	* times are UTIME_NOW), then we need to check for write permission
	222	*/
	223	if (ia_valid & ATTR_TOUCH) {
	224	if (IS_IMMUTABLE(inode))
	225	return -EPERM;
	226
	227	if (!inode_owner_or_capable(inode)) {
	228	error = inode_permission(inode, MAY_WRITE);
	229	if (error)
	230	return error;
	231	}
	232	}
	233
69b45732	234	if ((ia_valid & ATTR_MODE)) {
8d334acd	235	umode_t amode = attr->ia_mode;
69b45732 AK	236	/* Flag setting protected by i_mutex */
	237	if (is_sxid(amode))
	238	inode->i_flags &= ~S_NOSEC;
	239	}
	240
c2050a45	241	now = current_time(inode);
1da177e4 LT	242
	243	attr->ia_ctime = now;
	244	if (!(ia_valid & ATTR_ATIME_SET))
	245	attr->ia_atime = now;
	246	if (!(ia_valid & ATTR_MTIME_SET))
	247	attr->ia_mtime = now;
b5376771	248	if (ia_valid & ATTR_KILL_PRIV) {
b5376771	249	error = security_inode_need_killpriv(dentry);
030b533c	250	if (error < 0)
b5376771	251	return error;
030b533c JK	252	if (error == 0)
030b533c JK	253	ia_valid = attr->ia_valid &= ~ATTR_KILL_PRIV;
b5376771	254	}
6de0ec00 JL	255
	256	/*
	257	* We now pass ATTR_KILL_S*ID to the lower level setattr function so
	258	* that the function has the ability to reinterpret a mode change
	259	* that's due to these bits. This adds an implicit restriction that
	260	* no function will ever call notify_change with both ATTR_MODE and
	261	* ATTR_KILL_S*ID set.
	262	*/
	263	if ((ia_valid & (ATTR_KILL_SUID\|ATTR_KILL_SGID)) &&
	264	(ia_valid & ATTR_MODE))
	265	BUG();
	266
1da177e4	267	if (ia_valid & ATTR_KILL_SUID) {
1da177e4	268	if (mode & S_ISUID) {
6de0ec00 JL	269	ia_valid = attr->ia_valid \|= ATTR_MODE;
6de0ec00 JL	270	attr->ia_mode = (inode->i_mode & ~S_ISUID);
1da177e4 LT	271	}
	272	}
	273	if (ia_valid & ATTR_KILL_SGID) {
1da177e4 LT	274	if ((mode & (S_ISGID \| S_IXGRP)) == (S_ISGID \| S_IXGRP)) {
	275	if (!(ia_valid & ATTR_MODE)) {
	276	ia_valid = attr->ia_valid \|= ATTR_MODE;
	277	attr->ia_mode = inode->i_mode;
	278	}
	279	attr->ia_mode &= ~S_ISGID;
	280	}
	281	}
6de0ec00	282	if (!(attr->ia_valid & ~(ATTR_KILL_SUID \| ATTR_KILL_SGID)))
1da177e4 LT	283	return 0;
1da177e4 LT	284
a475acf0 SF	285	/*
	286	* Verify that uid/gid changes are valid in the target
	287	* namespace of the superblock.
	288	*/
	289	if (ia_valid & ATTR_UID &&
	290	!kuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid))
	291	return -EOVERFLOW;
	292	if (ia_valid & ATTR_GID &&
	293	!kgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid))
	294	return -EOVERFLOW;
	295
0bd23d09 EB	296	/* Don't allow modifications of files with invalid uids or
	297	* gids unless those uids & gids are being made valid.
	298	*/
	299	if (!(ia_valid & ATTR_UID) && !uid_valid(inode->i_uid))
	300	return -EOVERFLOW;
	301	if (!(ia_valid & ATTR_GID) && !gid_valid(inode->i_gid))
	302	return -EOVERFLOW;
	303
a77b72da	304	error = security_inode_setattr(dentry, attr);
27ac0ffe BF	305	if (error)
	306	return error;
	307	error = try_break_deleg(inode, delegated_inode);
a77b72da MS	308	if (error)
	309	return error;
	310
eef2380c	311	if (inode->i_op->setattr)
a77b72da	312	error = inode->i_op->setattr(dentry, attr);
eef2380c CH	313	else
eef2380c CH	314	error = simple_setattr(dentry, attr);
1da177e4	315
975d2943	316	if (!error) {
0eeca283	317	fsnotify_change(dentry, ia_valid);
9957a504	318	ima_inode_post_setattr(dentry);
975d2943 MZ	319	evm_inode_post_setattr(dentry, ia_valid);
975d2943 MZ	320	}
0eeca283	321
1da177e4 LT	322	return error;
1da177e4 LT	323	}
1da177e4	324	EXPORT_SYMBOL(notify_change);