[mirror_ubuntu-zesty-kernel.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/capability.h>
#include <linux/fsnotify.h>
#include <linux/fcntl.h>
#include <linux/security.h>
#include <linux/evm.h>
#include <linux/ima.h>

static bool chown_ok(const struct inode *inode, kuid_t uid)
{
	if (uid_eq(current_fsuid(), inode->i_uid) &&
	    uid_eq(uid, inode->i_uid))
		return true;
	if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
		return true;
	if (ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
		return true;
	return false;
}

static bool chgrp_ok(const struct inode *inode, kgid_t gid)
{
	if (uid_eq(current_fsuid(), inode->i_uid) &&
	    (in_group_p(gid) || gid_eq(gid, inode->i_gid)))
		return true;
	if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
		return true;
	if (ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
		return true;
	return false;
}

/**
 * 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) && !chown_ok(inode, attr->ia_uid))
		return -EPERM;

	/* Make sure caller can chgrp. */
	if ((ia_valid & ATTR_GID) && !chgrp_ok(inode, attr->ia_gid))
		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>
16f7e0fe	12	#include <linux/capability.h>
0eeca283	13	#include <linux/fsnotify.h>
1da177e4	14	#include <linux/fcntl.h>
1da177e4	15	#include <linux/security.h>
975d2943	16	#include <linux/evm.h>
9957a504	17	#include <linux/ima.h>
1da177e4	18
a6071d80 EB	19	static bool chown_ok(const struct inode *inode, kuid_t uid)
	20	{
	21	if (uid_eq(current_fsuid(), inode->i_uid) &&
	22	uid_eq(uid, inode->i_uid))
	23	return true;
	24	if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
	25	return true;
	26	if (ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
	27	return true;
	28	return false;
	29	}
	30
	31	static bool chgrp_ok(const struct inode *inode, kgid_t gid)
	32	{
	33	if (uid_eq(current_fsuid(), inode->i_uid) &&
	34	(in_group_p(gid) \|\| gid_eq(gid, inode->i_gid)))
	35	return true;
	36	if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
	37	return true;
	38	if (ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
	39	return true;
	40	return false;
	41	}
	42
2c27c65e	43	/**
31051c85 JK	44	* setattr_prepare - check if attribute changes to a dentry are allowed
31051c85 JK	45	* @dentry: dentry to check
2c27c65e CH	46	* @attr: attributes to change
	47	*
	48	* Check if we are allowed to change the attributes contained in @attr
31051c85 JK	49	* in the given dentry. This includes the normal unix access permission
	50	* checks, as well as checks for rlimits and others. The function also clears
	51	* SGID bit from mode if user is not allowed to set it. Also file capabilities
	52	* and IMA extended attributes are cleared if ATTR_KILL_PRIV is set.
2c27c65e CH	53	*
	54	* Should be called as the first thing in ->setattr implementations,
	55	* possibly after taking additional locks.
	56	*/
31051c85	57	int setattr_prepare(struct dentry dentry, struct iattr attr)
1da177e4	58	{
31051c85	59	struct inode *inode = d_inode(dentry);
1da177e4 LT	60	unsigned int ia_valid = attr->ia_valid;
1da177e4 LT	61
2c27c65e CH	62	/*
	63	* First check size constraints. These can't be overriden using
	64	* ATTR_FORCE.
	65	*/
	66	if (ia_valid & ATTR_SIZE) {
	67	int error = inode_newsize_ok(inode, attr->ia_size);
	68	if (error)
	69	return error;
	70	}
	71
1da177e4 LT	72	/* If force is set do it anyway. */
1da177e4 LT	73	if (ia_valid & ATTR_FORCE)
030b533c	74	goto kill_priv;
1da177e4 LT	75
1da177e4 LT	76	/* Make sure a caller can chown. */
a6071d80	77	if ((ia_valid & ATTR_UID) && !chown_ok(inode, attr->ia_uid))
2c27c65e	78	return -EPERM;
1da177e4 LT	79
1da177e4 LT	80	/* Make sure caller can chgrp. */
a6071d80	81	if ((ia_valid & ATTR_GID) && !chgrp_ok(inode, attr->ia_gid))
2c27c65e	82	return -EPERM;
1da177e4 LT	83
	84	/* Make sure a caller can chmod. */
	85	if (ia_valid & ATTR_MODE) {
2e149670	86	if (!inode_owner_or_capable(inode))
2c27c65e	87	return -EPERM;
1da177e4 LT	88	/* Also check the setgid bit! */
1da177e4 LT	89	if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
7fa294c8	90	inode->i_gid) &&
23adbe12	91	!capable_wrt_inode_uidgid(inode, CAP_FSETID))
1da177e4 LT	92	attr->ia_mode &= ~S_ISGID;
	93	}
	94
	95	/* Check for setting the inode time. */
9767d749	96	if (ia_valid & (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)) {
2e149670	97	if (!inode_owner_or_capable(inode))
2c27c65e	98	return -EPERM;
1da177e4	99	}
2c27c65e	100
030b533c JK	101	kill_priv:
	102	/* User has permission for the change */
	103	if (ia_valid & ATTR_KILL_PRIV) {
	104	int error;
	105
	106	error = security_inode_killpriv(dentry);
	107	if (error)
	108	return error;
	109	}
	110
2c27c65e	111	return 0;
1da177e4	112	}
31051c85	113	EXPORT_SYMBOL(setattr_prepare);
1da177e4	114
25d9e2d1	115	/**
	116	* inode_newsize_ok - may this inode be truncated to a given size
	117	* @inode: the inode to be truncated
	118	* @offset: the new size to assign to the inode
	119	* @Returns: 0 on success, -ve errno on failure
	120	*
7bb46a67	121	* inode_newsize_ok must be called with i_mutex held.
7bb46a67	122	*
25d9e2d1	123	* inode_newsize_ok will check filesystem limits and ulimits to check that the
	124	* new inode size is within limits. inode_newsize_ok will also send SIGXFSZ
	125	* when necessary. Caller must not proceed with inode size change if failure is
	126	* returned. @inode must be a file (not directory), with appropriate
	127	* permissions to allow truncate (inode_newsize_ok does NOT check these
	128	* conditions).
25d9e2d1	129	*/
	130	int inode_newsize_ok(const struct inode *inode, loff_t offset)
	131	{
	132	if (inode->i_size < offset) {
	133	unsigned long limit;
	134
d554ed89	135	limit = rlimit(RLIMIT_FSIZE);
25d9e2d1	136	if (limit != RLIM_INFINITY && offset > limit)
	137	goto out_sig;
	138	if (offset > inode->i_sb->s_maxbytes)
	139	goto out_big;
	140	} else {
	141	/*
	142	* truncation of in-use swapfiles is disallowed - it would
	143	* cause subsequent swapout to scribble on the now-freed
	144	* blocks.
	145	*/
	146	if (IS_SWAPFILE(inode))
	147	return -ETXTBSY;
	148	}
	149
	150	return 0;
	151	out_sig:
	152	send_sig(SIGXFSZ, current, 0);
	153	out_big:
	154	return -EFBIG;
	155	}
	156	EXPORT_SYMBOL(inode_newsize_ok);
	157
7bb46a67	158	/**
6a1a90ad	159	* setattr_copy - copy simple metadata updates into the generic inode
7bb46a67	160	* @inode: the inode to be updated
	161	* @attr: the new attributes
	162	*
6a1a90ad	163	* setattr_copy must be called with i_mutex held.
7bb46a67	164	*
6a1a90ad	165	* setattr_copy updates the inode's metadata with that specified
25985edc	166	* in attr. Noticeably missing is inode size update, which is more complex
2c27c65e	167	* as it requires pagecache updates.
7bb46a67	168	*
	169	* The inode is not marked as dirty after this operation. The rationale is
	170	* that for "simple" filesystems, the struct inode is the inode storage.
	171	* The caller is free to mark the inode dirty afterwards if needed.
	172	*/
6a1a90ad	173	void setattr_copy(struct inode inode, const struct iattr attr)
1da177e4 LT	174	{
1da177e4 LT	175	unsigned int ia_valid = attr->ia_valid;
4a30131e	176
1da177e4 LT	177	if (ia_valid & ATTR_UID)
	178	inode->i_uid = attr->ia_uid;
	179	if (ia_valid & ATTR_GID)
	180	inode->i_gid = attr->ia_gid;
	181	if (ia_valid & ATTR_ATIME)
	182	inode->i_atime = timespec_trunc(attr->ia_atime,
	183	inode->i_sb->s_time_gran);
	184	if (ia_valid & ATTR_MTIME)
	185	inode->i_mtime = timespec_trunc(attr->ia_mtime,
	186	inode->i_sb->s_time_gran);
	187	if (ia_valid & ATTR_CTIME)
	188	inode->i_ctime = timespec_trunc(attr->ia_ctime,
	189	inode->i_sb->s_time_gran);
	190	if (ia_valid & ATTR_MODE) {
	191	umode_t mode = attr->ia_mode;
	192
7fa294c8	193	if (!in_group_p(inode->i_gid) &&
23adbe12	194	!capable_wrt_inode_uidgid(inode, CAP_FSETID))
1da177e4 LT	195	mode &= ~S_ISGID;
	196	inode->i_mode = mode;
	197	}
7bb46a67	198	}
6a1a90ad	199	EXPORT_SYMBOL(setattr_copy);
7bb46a67	200
27ac0ffe BF	201	/**
	202	* notify_change - modify attributes of a filesytem object
	203	* @dentry: object affected
	204	* @iattr: new attributes
	205	* @delegated_inode: returns inode, if the inode is delegated
	206	*
	207	* The caller must hold the i_mutex on the affected object.
	208	*
	209	* If notify_change discovers a delegation in need of breaking,
	210	* it will return -EWOULDBLOCK and return a reference to the inode in
	211	* delegated_inode. The caller should then break the delegation and
	212	* retry. Because breaking a delegation may take a long time, the
	213	* caller should drop the i_mutex before doing so.
	214	*
	215	* Alternatively, a caller may pass NULL for delegated_inode. This may
	216	* be appropriate for callers that expect the underlying filesystem not
	217	* to be NFS exported. Also, passing NULL is fine for callers holding
	218	* the file open for write, as there can be no conflicting delegation in
	219	* that case.
	220	*/
	221	int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
1da177e4 LT	222	{
1da177e4 LT	223	struct inode *inode = dentry->d_inode;
8d334acd	224	umode_t mode = inode->i_mode;
1da177e4 LT	225	int error;
	226	struct timespec now;
	227	unsigned int ia_valid = attr->ia_valid;
	228
5955102c	229	WARN_ON_ONCE(!inode_is_locked(inode));
c4107b30	230
beb29e05 MS	231	if (ia_valid & (ATTR_MODE \| ATTR_UID \| ATTR_GID \| ATTR_TIMES_SET)) {
	232	if (IS_IMMUTABLE(inode) \|\| IS_APPEND(inode))
	233	return -EPERM;
	234	}
	235
f2b20f6e MS	236	/*
	237	* If utimes(2) and friends are called with times == NULL (or both
	238	* times are UTIME_NOW), then we need to check for write permission
	239	*/
	240	if (ia_valid & ATTR_TOUCH) {
	241	if (IS_IMMUTABLE(inode))
	242	return -EPERM;
	243
	244	if (!inode_owner_or_capable(inode)) {
	245	error = inode_permission(inode, MAY_WRITE);
	246	if (error)
	247	return error;
	248	}
	249	}
	250
69b45732	251	if ((ia_valid & ATTR_MODE)) {
8d334acd	252	umode_t amode = attr->ia_mode;
69b45732 AK	253	/* Flag setting protected by i_mutex */
	254	if (is_sxid(amode))
	255	inode->i_flags &= ~S_NOSEC;
	256	}
	257
c2050a45	258	now = current_time(inode);
1da177e4 LT	259
	260	attr->ia_ctime = now;
	261	if (!(ia_valid & ATTR_ATIME_SET))
	262	attr->ia_atime = now;
	263	if (!(ia_valid & ATTR_MTIME_SET))
	264	attr->ia_mtime = now;
b5376771	265	if (ia_valid & ATTR_KILL_PRIV) {
b5376771	266	error = security_inode_need_killpriv(dentry);
030b533c	267	if (error < 0)
b5376771	268	return error;
030b533c JK	269	if (error == 0)
030b533c JK	270	ia_valid = attr->ia_valid &= ~ATTR_KILL_PRIV;
b5376771	271	}
6de0ec00 JL	272
	273	/*
	274	* We now pass ATTR_KILL_S*ID to the lower level setattr function so
	275	* that the function has the ability to reinterpret a mode change
	276	* that's due to these bits. This adds an implicit restriction that
	277	* no function will ever call notify_change with both ATTR_MODE and
	278	* ATTR_KILL_S*ID set.
	279	*/
	280	if ((ia_valid & (ATTR_KILL_SUID\|ATTR_KILL_SGID)) &&
	281	(ia_valid & ATTR_MODE))
	282	BUG();
	283
1da177e4	284	if (ia_valid & ATTR_KILL_SUID) {
1da177e4	285	if (mode & S_ISUID) {
6de0ec00 JL	286	ia_valid = attr->ia_valid \|= ATTR_MODE;
6de0ec00 JL	287	attr->ia_mode = (inode->i_mode & ~S_ISUID);
1da177e4 LT	288	}
	289	}
	290	if (ia_valid & ATTR_KILL_SGID) {
1da177e4 LT	291	if ((mode & (S_ISGID \| S_IXGRP)) == (S_ISGID \| S_IXGRP)) {
	292	if (!(ia_valid & ATTR_MODE)) {
	293	ia_valid = attr->ia_valid \|= ATTR_MODE;
	294	attr->ia_mode = inode->i_mode;
	295	}
	296	attr->ia_mode &= ~S_ISGID;
	297	}
	298	}
6de0ec00	299	if (!(attr->ia_valid & ~(ATTR_KILL_SUID \| ATTR_KILL_SGID)))
1da177e4 LT	300	return 0;
1da177e4 LT	301
a475acf0 SF	302	/*
	303	* Verify that uid/gid changes are valid in the target
	304	* namespace of the superblock.
	305	*/
	306	if (ia_valid & ATTR_UID &&
	307	!kuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid))
	308	return -EOVERFLOW;
	309	if (ia_valid & ATTR_GID &&
	310	!kgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid))
	311	return -EOVERFLOW;
	312
0bd23d09 EB	313	/* Don't allow modifications of files with invalid uids or
	314	* gids unless those uids & gids are being made valid.
	315	*/
	316	if (!(ia_valid & ATTR_UID) && !uid_valid(inode->i_uid))
	317	return -EOVERFLOW;
	318	if (!(ia_valid & ATTR_GID) && !gid_valid(inode->i_gid))
	319	return -EOVERFLOW;
	320
a77b72da	321	error = security_inode_setattr(dentry, attr);
27ac0ffe BF	322	if (error)
	323	return error;
	324	error = try_break_deleg(inode, delegated_inode);
a77b72da MS	325	if (error)
	326	return error;
	327
eef2380c	328	if (inode->i_op->setattr)
a77b72da	329	error = inode->i_op->setattr(dentry, attr);
eef2380c CH	330	else
eef2380c CH	331	error = simple_setattr(dentry, attr);
1da177e4	332
975d2943	333	if (!error) {
0eeca283	334	fsnotify_change(dentry, ia_valid);
9957a504	335	ima_inode_post_setattr(dentry);
975d2943 MZ	336	evm_inode_post_setattr(dentry, ia_valid);
975d2943 MZ	337	}
0eeca283	338
1da177e4 LT	339	return error;
1da177e4 LT	340	}
1da177e4	341	EXPORT_SYMBOL(notify_change);