[mirror_ubuntu-bionic-kernel.git] / fs / ext4 / acl.c

// SPDX-License-Identifier: GPL-2.0
/*
 * linux/fs/ext4/acl.c
 *
 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
 */

#include <linux/quotaops.h>
#include "ext4_jbd2.h"
#include "ext4.h"
#include "xattr.h"
#include "acl.h"

/*
 * Convert from filesystem to in-memory representation.
 */
static struct posix_acl *
ext4_acl_from_disk(struct super_block *sb, const void *value, size_t size)
{
	const char *end = (char *)value + size;
	int n, count;
	struct posix_acl *acl;

	if (!value)
		return NULL;
	if (size < sizeof(ext4_acl_header))
		 return ERR_PTR(-EINVAL);
	if (((ext4_acl_header *)value)->a_version !=
	    cpu_to_le32(EXT4_ACL_VERSION))
		return ERR_PTR(-EINVAL);
	value = (char *)value + sizeof(ext4_acl_header);
	count = ext4_acl_count(size);
	if (count < 0)
		return ERR_PTR(-EINVAL);
	if (count == 0)
		return NULL;
	acl = posix_acl_alloc(count, GFP_NOFS);
	if (!acl)
		return ERR_PTR(-ENOMEM);
	for (n = 0; n < count; n++) {
		ext4_acl_entry *entry =
			(ext4_acl_entry *)value;
		if ((char *)value + sizeof(ext4_acl_entry_short) > end)
			goto fail;
		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);

		switch (acl->a_entries[n].e_tag) {
		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			value = (char *)value +
				sizeof(ext4_acl_entry_short);
			break;

		case ACL_USER:
			value = (char *)value + sizeof(ext4_acl_entry);
			if ((char *)value > end)
				goto fail;
			acl->a_entries[n].e_uid =
				make_kuid(sb->s_user_ns,
					  le32_to_cpu(entry->e_id));
			if (!uid_valid(acl->a_entries[n].e_uid))
				goto fail;
			break;
		case ACL_GROUP:
			value = (char *)value + sizeof(ext4_acl_entry);
			if ((char *)value > end)
				goto fail;
			acl->a_entries[n].e_gid =
				make_kgid(sb->s_user_ns,
					  le32_to_cpu(entry->e_id));
			if (!gid_valid(acl->a_entries[n].e_gid))
				goto fail;
			break;

		default:
			goto fail;
		}
	}
	if (value != end)
		goto fail;
	return acl;

fail:
	posix_acl_release(acl);
	return ERR_PTR(-EINVAL);
}

/*
 * Convert from in-memory to filesystem representation.
 */
static void *
ext4_acl_to_disk(struct super_block *sb, const struct posix_acl *acl,
		 size_t *size)
{
	ext4_acl_header *ext_acl;
	char *e;
	size_t n;
	uid_t uid;
	gid_t gid;

	*size = ext4_acl_size(acl->a_count);
	ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
			sizeof(ext4_acl_entry), GFP_NOFS);
	if (!ext_acl)
		return ERR_PTR(-ENOMEM);
	ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
	e = (char *)ext_acl + sizeof(ext4_acl_header);
	for (n = 0; n < acl->a_count; n++) {
		const struct posix_acl_entry *acl_e = &acl->a_entries[n];
		ext4_acl_entry *entry = (ext4_acl_entry *)e;
		entry->e_tag  = cpu_to_le16(acl_e->e_tag);
		entry->e_perm = cpu_to_le16(acl_e->e_perm);
		switch (acl_e->e_tag) {
		case ACL_USER:
			uid = from_kuid(sb->s_user_ns, acl_e->e_uid);
			if (uid == (uid_t)-1)
				goto fail;
			entry->e_id = cpu_to_le32(uid);
			e += sizeof(ext4_acl_entry);
			break;
		case ACL_GROUP:
			gid = from_kgid(sb->s_user_ns, acl_e->e_gid);
			if (gid == (gid_t)-1)
				goto fail;
			entry->e_id = cpu_to_le32(gid);
			e += sizeof(ext4_acl_entry);
			break;

		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			e += sizeof(ext4_acl_entry_short);
			break;

		default:
			goto fail;
		}
	}
	return (char *)ext_acl;

fail:
	kfree(ext_acl);
	return ERR_PTR(-EINVAL);
}

/*
 * Inode operation get_posix_acl().
 *
 * inode->i_mutex: don't care
 */
struct posix_acl *
ext4_get_acl(struct inode *inode, int type)
{
	int name_index;
	char *value = NULL;
	struct posix_acl *acl;
	int retval;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
		break;
	default:
		BUG();
	}
	retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
	if (retval > 0) {
		value = kmalloc(retval, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
		retval = ext4_xattr_get(inode, name_index, "", value, retval);
	}
	if (retval > 0)
		acl = ext4_acl_from_disk(inode->i_sb, value, retval);
	else if (retval == -ENODATA || retval == -ENOSYS)
		acl = NULL;
	else
		acl = ERR_PTR(retval);
	kfree(value);

	return acl;
}

/*
 * Set the access or default ACL of an inode.
 *
 * inode->i_mutex: down unless called from ext4_new_inode
 */
static int
__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
	     struct posix_acl *acl, int xattr_flags)
{
	int name_index;
	void *value = NULL;
	size_t size = 0;
	int error;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
		break;

	case ACL_TYPE_DEFAULT:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EACCES : 0;
		break;

	default:
		return -EINVAL;
	}
	if (acl) {
		value = ext4_acl_to_disk(inode->i_sb, acl, &size);
		if (IS_ERR(value))
			return (int)PTR_ERR(value);
	}

	error = ext4_xattr_set_handle(handle, inode, name_index, "",
				      value, size, xattr_flags);

	kfree(value);
	if (!error) {
		set_cached_acl(inode, type, acl);
	}

	return error;
}

int
ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
	handle_t *handle;
	int error, credits, retries = 0;
	size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0;
	umode_t mode = inode->i_mode;
	int update_mode = 0;

	error = dquot_initialize(inode);
	if (error)
		return error;
retry:
	error = ext4_xattr_set_credits(inode, acl_size, false /* is_create */,
				       &credits);
	if (error)
		return error;

	handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if ((type == ACL_TYPE_ACCESS) && acl) {
		error = posix_acl_update_mode(inode, &mode, &acl);
		if (error)
			goto out_stop;
		update_mode = 1;
	}

	error = __ext4_set_acl(handle, inode, type, acl, 0 /* xattr_flags */);
	if (!error && update_mode) {
		inode->i_mode = mode;
		inode->i_ctime = current_time(inode);
		ext4_mark_inode_dirty(handle, inode);
	}
out_stop:
	ext4_journal_stop(handle);
	if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
		goto retry;
	return error;
}

/*
 * Initialize the ACLs of a new inode. Called from ext4_new_inode.
 *
 * dir->i_mutex: down
 * inode->i_mutex: up (access to inode is still exclusive)
 */
int
ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
{
	struct posix_acl *default_acl, *acl;
	int error;

	error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
	if (error)
		return error;

	if (default_acl) {
		error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
				       default_acl, XATTR_CREATE);
		posix_acl_release(default_acl);
	}
	if (acl) {
		if (!error)
			error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
					       acl, XATTR_CREATE);
		posix_acl_release(acl);
	}
	return error;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
ac27a0ec	2	/*
617ba13b	3	* linux/fs/ext4/acl.c
ac27a0ec DK	4	*
	5	* Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
	6	*/
	7
b8cb5a54	8	#include <linux/quotaops.h>
3dcf5451 CH	9	#include "ext4_jbd2.h"
3dcf5451 CH	10	#include "ext4.h"
ac27a0ec DK	11	#include "xattr.h"
	12	#include "acl.h"
	13
	14	/*
	15	* Convert from filesystem to in-memory representation.
	16	*/
	17	static struct posix_acl *
78a8da10	18	ext4_acl_from_disk(struct super_block sb, const void value, size_t size)
ac27a0ec DK	19	{
	20	const char end = (char )value + size;
	21	int n, count;
	22	struct posix_acl *acl;
	23
	24	if (!value)
	25	return NULL;
617ba13b	26	if (size < sizeof(ext4_acl_header))
ac27a0ec	27	return ERR_PTR(-EINVAL);
617ba13b MC	28	if (((ext4_acl_header *)value)->a_version !=
617ba13b MC	29	cpu_to_le32(EXT4_ACL_VERSION))
ac27a0ec	30	return ERR_PTR(-EINVAL);
617ba13b MC	31	value = (char *)value + sizeof(ext4_acl_header);
617ba13b MC	32	count = ext4_acl_count(size);
ac27a0ec DK	33	if (count < 0)
	34	return ERR_PTR(-EINVAL);
	35	if (count == 0)
	36	return NULL;
216553c4	37	acl = posix_acl_alloc(count, GFP_NOFS);
ac27a0ec DK	38	if (!acl)
ac27a0ec DK	39	return ERR_PTR(-ENOMEM);
2b2d6d01	40	for (n = 0; n < count; n++) {
617ba13b MC	41	ext4_acl_entry *entry =
	42	(ext4_acl_entry *)value;
	43	if ((char *)value + sizeof(ext4_acl_entry_short) > end)
ac27a0ec DK	44	goto fail;
	45	acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
	46	acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
2b2d6d01 TT	47
	48	switch (acl->a_entries[n].e_tag) {
	49	case ACL_USER_OBJ:
	50	case ACL_GROUP_OBJ:
	51	case ACL_MASK:
	52	case ACL_OTHER:
	53	value = (char *)value +
	54	sizeof(ext4_acl_entry_short);
2b2d6d01 TT	55	break;
	56
	57	case ACL_USER:
af84df93 EB	58	value = (char *)value + sizeof(ext4_acl_entry);
	59	if ((char *)value > end)
	60	goto fail;
	61	acl->a_entries[n].e_uid =
78a8da10	62	make_kuid(sb->s_user_ns,
af84df93	63	le32_to_cpu(entry->e_id));
78a8da10 SF	64	if (!uid_valid(acl->a_entries[n].e_uid))
78a8da10 SF	65	goto fail;
af84df93	66	break;
2b2d6d01 TT	67	case ACL_GROUP:
	68	value = (char *)value + sizeof(ext4_acl_entry);
	69	if ((char *)value > end)
ac27a0ec	70	goto fail;
af84df93	71	acl->a_entries[n].e_gid =
78a8da10	72	make_kgid(sb->s_user_ns,
af84df93	73	le32_to_cpu(entry->e_id));
78a8da10 SF	74	if (!gid_valid(acl->a_entries[n].e_gid))
78a8da10 SF	75	goto fail;
2b2d6d01 TT	76	break;
	77
	78	default:
	79	goto fail;
ac27a0ec DK	80	}
	81	}
	82	if (value != end)
	83	goto fail;
	84	return acl;
	85
	86	fail:
	87	posix_acl_release(acl);
	88	return ERR_PTR(-EINVAL);
	89	}
	90
	91	/*
	92	* Convert from in-memory to filesystem representation.
	93	*/
	94	static void *
78a8da10 SF	95	ext4_acl_to_disk(struct super_block sb, const struct posix_acl acl,
78a8da10 SF	96	size_t *size)
ac27a0ec	97	{
617ba13b	98	ext4_acl_header *ext_acl;
ac27a0ec DK	99	char *e;
ac27a0ec DK	100	size_t n;
78a8da10 SF	101	uid_t uid;
78a8da10 SF	102	gid_t gid;
ac27a0ec	103
617ba13b MC	104	*size = ext4_acl_size(acl->a_count);
617ba13b MC	105	ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
216553c4	106	sizeof(ext4_acl_entry), GFP_NOFS);
ac27a0ec DK	107	if (!ext_acl)
ac27a0ec DK	108	return ERR_PTR(-ENOMEM);
617ba13b MC	109	ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
617ba13b MC	110	e = (char *)ext_acl + sizeof(ext4_acl_header);
2b2d6d01	111	for (n = 0; n < acl->a_count; n++) {
af84df93	112	const struct posix_acl_entry *acl_e = &acl->a_entries[n];
617ba13b	113	ext4_acl_entry entry = (ext4_acl_entry )e;
af84df93 EB	114	entry->e_tag = cpu_to_le16(acl_e->e_tag);
	115	entry->e_perm = cpu_to_le16(acl_e->e_perm);
	116	switch (acl_e->e_tag) {
2b2d6d01	117	case ACL_USER:
78a8da10 SF	118	uid = from_kuid(sb->s_user_ns, acl_e->e_uid);
	119	if (uid == (uid_t)-1)
	120	goto fail;
	121	entry->e_id = cpu_to_le32(uid);
af84df93 EB	122	e += sizeof(ext4_acl_entry);
af84df93 EB	123	break;
2b2d6d01	124	case ACL_GROUP:
78a8da10 SF	125	gid = from_kgid(sb->s_user_ns, acl_e->e_gid);
	126	if (gid == (gid_t)-1)
	127	goto fail;
	128	entry->e_id = cpu_to_le32(gid);
2b2d6d01 TT	129	e += sizeof(ext4_acl_entry);
	130	break;
	131
	132	case ACL_USER_OBJ:
	133	case ACL_GROUP_OBJ:
	134	case ACL_MASK:
	135	case ACL_OTHER:
	136	e += sizeof(ext4_acl_entry_short);
	137	break;
	138
	139	default:
	140	goto fail;
ac27a0ec DK	141	}
	142	}
	143	return (char *)ext_acl;
	144
	145	fail:
	146	kfree(ext_acl);
	147	return ERR_PTR(-EINVAL);
	148	}
	149
ac27a0ec DK	150	/*
	151	* Inode operation get_posix_acl().
	152	*
	153	* inode->i_mutex: don't care
	154	*/
4e34e719	155	struct posix_acl *
617ba13b	156	ext4_get_acl(struct inode *inode, int type)
ac27a0ec	157	{
ac27a0ec DK	158	int name_index;
	159	char *value = NULL;
	160	struct posix_acl *acl;
	161	int retval;
	162
2b2d6d01 TT	163	switch (type) {
2b2d6d01 TT	164	case ACL_TYPE_ACCESS:
2b2d6d01 TT	165	name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
2b2d6d01 TT	166	break;
2b2d6d01	167	case ACL_TYPE_DEFAULT:
2b2d6d01 TT	168	name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
2b2d6d01 TT	169	break;
2b2d6d01	170	default:
073aaa1b	171	BUG();
ac27a0ec	172	}
617ba13b	173	retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
ac27a0ec	174	if (retval > 0) {
216553c4	175	value = kmalloc(retval, GFP_NOFS);
ac27a0ec DK	176	if (!value)
ac27a0ec DK	177	return ERR_PTR(-ENOMEM);
617ba13b	178	retval = ext4_xattr_get(inode, name_index, "", value, retval);
ac27a0ec DK	179	}
ac27a0ec DK	180	if (retval > 0)
78a8da10	181	acl = ext4_acl_from_disk(inode->i_sb, value, retval);
ac27a0ec DK	182	else if (retval == -ENODATA \|\| retval == -ENOSYS)
	183	acl = NULL;
	184	else
	185	acl = ERR_PTR(retval);
	186	kfree(value);
	187
ac27a0ec DK	188	return acl;
	189	}
	190
	191	/*
	192	* Set the access or default ACL of an inode.
	193	*
617ba13b	194	* inode->i_mutex: down unless called from ext4_new_inode
ac27a0ec DK	195	*/
ac27a0ec DK	196	static int
64e178a7	197	__ext4_set_acl(handle_t handle, struct inode inode, int type,
af65207c	198	struct posix_acl *acl, int xattr_flags)
ac27a0ec	199	{
ac27a0ec DK	200	int name_index;
	201	void *value = NULL;
	202	size_t size = 0;
	203	int error;
	204
2b2d6d01 TT	205	switch (type) {
	206	case ACL_TYPE_ACCESS:
	207	name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
2b2d6d01	208	break;
ac27a0ec	209
2b2d6d01 TT	210	case ACL_TYPE_DEFAULT:
	211	name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
	212	if (!S_ISDIR(inode->i_mode))
	213	return acl ? -EACCES : 0;
	214	break;
ac27a0ec	215
2b2d6d01 TT	216	default:
2b2d6d01 TT	217	return -EINVAL;
ac27a0ec DK	218	}
ac27a0ec DK	219	if (acl) {
78a8da10	220	value = ext4_acl_to_disk(inode->i_sb, acl, &size);
ac27a0ec DK	221	if (IS_ERR(value))
	222	return (int)PTR_ERR(value);
	223	}
	224
617ba13b	225	error = ext4_xattr_set_handle(handle, inode, name_index, "",
af65207c	226	value, size, xattr_flags);
ac27a0ec DK	227
ac27a0ec DK	228	kfree(value);
397e4341	229	if (!error) {
073aaa1b	230	set_cached_acl(inode, type, acl);
397e4341	231	}
2b2d6d01	232
ac27a0ec DK	233	return error;
	234	}
	235
ac27a0ec	236	int
64e178a7	237	ext4_set_acl(struct inode inode, struct posix_acl acl, int type)
ac27a0ec	238	{
bc26ab5f	239	handle_t *handle;
c1a5d5f6 TE	240	int error, credits, retries = 0;
c1a5d5f6 TE	241	size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0;
a3bb2d55 JK	242	umode_t mode = inode->i_mode;
a3bb2d55 JK	243	int update_mode = 0;
bc26ab5f	244
b8cb5a54 TE	245	error = dquot_initialize(inode);
	246	if (error)
	247	return error;
bc26ab5f	248	retry:
af65207c TE	249	error = ext4_xattr_set_credits(inode, acl_size, false /* is_create */,
af65207c TE	250	&credits);
dec214d0 TE	251	if (error)
	252	return error;
	253
c1a5d5f6	254	handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
64e178a7 CH	255	if (IS_ERR(handle))
	256	return PTR_ERR(handle);
	257
a3bb2d55 JK	258	if ((type == ACL_TYPE_ACCESS) && acl) {
	259	error = posix_acl_update_mode(inode, &mode, &acl);
	260	if (error)
	261	goto out_stop;
	262	update_mode = 1;
	263	}
	264
af65207c	265	error = __ext4_set_acl(handle, inode, type, acl, 0 /* xattr_flags */);
a3bb2d55 JK	266	if (!error && update_mode) {
	267	inode->i_mode = mode;
	268	inode->i_ctime = current_time(inode);
	269	ext4_mark_inode_dirty(handle, inode);
	270	}
	271	out_stop:
bc26ab5f	272	ext4_journal_stop(handle);
64e178a7	273	if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
bc26ab5f	274	goto retry;
ac27a0ec DK	275	return error;
	276	}
	277
	278	/*
64e178a7 CH	279	* Initialize the ACLs of a new inode. Called from ext4_new_inode.
	280	*
	281	* dir->i_mutex: down
	282	* inode->i_mutex: up (access to inode is still exclusive)
ac27a0ec	283	*/
64e178a7 CH	284	int
64e178a7 CH	285	ext4_init_acl(handle_t handle, struct inode inode, struct inode *dir)
ac27a0ec	286	{
64e178a7	287	struct posix_acl default_acl, acl;
ac27a0ec DK	288	int error;
ac27a0ec DK	289
64e178a7 CH	290	error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
	291	if (error)
	292	return error;
ac27a0ec	293
64e178a7 CH	294	if (default_acl) {
64e178a7 CH	295	error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
af65207c	296	default_acl, XATTR_CREATE);
64e178a7 CH	297	posix_acl_release(default_acl);
	298	}
	299	if (acl) {
	300	if (!error)
	301	error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
af65207c	302	acl, XATTR_CREATE);
64e178a7	303	posix_acl_release(acl);
24ec19b0	304	}
ac27a0ec DK	305	return error;
ac27a0ec DK	306	}