cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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dir.c (14409B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *  linux/fs/hfsplus/dir.c
      4 *
      5 * Copyright (C) 2001
      6 * Brad Boyer (flar@allandria.com)
      7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
      8 *
      9 * Handling of directories
     10 */
     11
     12#include <linux/errno.h>
     13#include <linux/fs.h>
     14#include <linux/slab.h>
     15#include <linux/random.h>
     16#include <linux/nls.h>
     17
     18#include "hfsplus_fs.h"
     19#include "hfsplus_raw.h"
     20#include "xattr.h"
     21
     22static inline void hfsplus_instantiate(struct dentry *dentry,
     23				       struct inode *inode, u32 cnid)
     24{
     25	dentry->d_fsdata = (void *)(unsigned long)cnid;
     26	d_instantiate(dentry, inode);
     27}
     28
     29/* Find the entry inside dir named dentry->d_name */
     30static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
     31				     unsigned int flags)
     32{
     33	struct inode *inode = NULL;
     34	struct hfs_find_data fd;
     35	struct super_block *sb;
     36	hfsplus_cat_entry entry;
     37	int err;
     38	u32 cnid, linkid = 0;
     39	u16 type;
     40
     41	sb = dir->i_sb;
     42
     43	dentry->d_fsdata = NULL;
     44	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
     45	if (err)
     46		return ERR_PTR(err);
     47	err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino,
     48			&dentry->d_name);
     49	if (unlikely(err < 0))
     50		goto fail;
     51again:
     52	err = hfs_brec_read(&fd, &entry, sizeof(entry));
     53	if (err) {
     54		if (err == -ENOENT) {
     55			hfs_find_exit(&fd);
     56			/* No such entry */
     57			inode = NULL;
     58			goto out;
     59		}
     60		goto fail;
     61	}
     62	type = be16_to_cpu(entry.type);
     63	if (type == HFSPLUS_FOLDER) {
     64		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
     65			err = -EIO;
     66			goto fail;
     67		}
     68		cnid = be32_to_cpu(entry.folder.id);
     69		dentry->d_fsdata = (void *)(unsigned long)cnid;
     70	} else if (type == HFSPLUS_FILE) {
     71		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
     72			err = -EIO;
     73			goto fail;
     74		}
     75		cnid = be32_to_cpu(entry.file.id);
     76		if (entry.file.user_info.fdType ==
     77				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
     78				entry.file.user_info.fdCreator ==
     79				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
     80				HFSPLUS_SB(sb)->hidden_dir &&
     81				(entry.file.create_date ==
     82					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
     83						create_date ||
     84				entry.file.create_date ==
     85					HFSPLUS_I(d_inode(sb->s_root))->
     86						create_date)) {
     87			struct qstr str;
     88			char name[32];
     89
     90			if (dentry->d_fsdata) {
     91				/*
     92				 * We found a link pointing to another link,
     93				 * so ignore it and treat it as regular file.
     94				 */
     95				cnid = (unsigned long)dentry->d_fsdata;
     96				linkid = 0;
     97			} else {
     98				dentry->d_fsdata = (void *)(unsigned long)cnid;
     99				linkid =
    100					be32_to_cpu(entry.file.permissions.dev);
    101				str.len = sprintf(name, "iNode%d", linkid);
    102				str.name = name;
    103				err = hfsplus_cat_build_key(sb, fd.search_key,
    104					HFSPLUS_SB(sb)->hidden_dir->i_ino,
    105					&str);
    106				if (unlikely(err < 0))
    107					goto fail;
    108				goto again;
    109			}
    110		} else if (!dentry->d_fsdata)
    111			dentry->d_fsdata = (void *)(unsigned long)cnid;
    112	} else {
    113		pr_err("invalid catalog entry type in lookup\n");
    114		err = -EIO;
    115		goto fail;
    116	}
    117	hfs_find_exit(&fd);
    118	inode = hfsplus_iget(dir->i_sb, cnid);
    119	if (IS_ERR(inode))
    120		return ERR_CAST(inode);
    121	if (S_ISREG(inode->i_mode))
    122		HFSPLUS_I(inode)->linkid = linkid;
    123out:
    124	return d_splice_alias(inode, dentry);
    125fail:
    126	hfs_find_exit(&fd);
    127	return ERR_PTR(err);
    128}
    129
    130static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
    131{
    132	struct inode *inode = file_inode(file);
    133	struct super_block *sb = inode->i_sb;
    134	int len, err;
    135	char *strbuf;
    136	hfsplus_cat_entry entry;
    137	struct hfs_find_data fd;
    138	struct hfsplus_readdir_data *rd;
    139	u16 type;
    140
    141	if (file->f_pos >= inode->i_size)
    142		return 0;
    143
    144	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
    145	if (err)
    146		return err;
    147	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
    148	if (!strbuf) {
    149		err = -ENOMEM;
    150		goto out;
    151	}
    152	hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
    153	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
    154	if (err)
    155		goto out;
    156
    157	if (ctx->pos == 0) {
    158		/* This is completely artificial... */
    159		if (!dir_emit_dot(file, ctx))
    160			goto out;
    161		ctx->pos = 1;
    162	}
    163	if (ctx->pos == 1) {
    164		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
    165			err = -EIO;
    166			goto out;
    167		}
    168
    169		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
    170			fd.entrylength);
    171		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
    172			pr_err("bad catalog folder thread\n");
    173			err = -EIO;
    174			goto out;
    175		}
    176		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
    177			pr_err("truncated catalog thread\n");
    178			err = -EIO;
    179			goto out;
    180		}
    181		if (!dir_emit(ctx, "..", 2,
    182			    be32_to_cpu(entry.thread.parentID), DT_DIR))
    183			goto out;
    184		ctx->pos = 2;
    185	}
    186	if (ctx->pos >= inode->i_size)
    187		goto out;
    188	err = hfs_brec_goto(&fd, ctx->pos - 1);
    189	if (err)
    190		goto out;
    191	for (;;) {
    192		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
    193			pr_err("walked past end of dir\n");
    194			err = -EIO;
    195			goto out;
    196		}
    197
    198		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
    199			err = -EIO;
    200			goto out;
    201		}
    202
    203		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
    204			fd.entrylength);
    205		type = be16_to_cpu(entry.type);
    206		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
    207		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
    208		if (err)
    209			goto out;
    210		if (type == HFSPLUS_FOLDER) {
    211			if (fd.entrylength <
    212					sizeof(struct hfsplus_cat_folder)) {
    213				pr_err("small dir entry\n");
    214				err = -EIO;
    215				goto out;
    216			}
    217			if (HFSPLUS_SB(sb)->hidden_dir &&
    218			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
    219					be32_to_cpu(entry.folder.id))
    220				goto next;
    221			if (!dir_emit(ctx, strbuf, len,
    222				    be32_to_cpu(entry.folder.id), DT_DIR))
    223				break;
    224		} else if (type == HFSPLUS_FILE) {
    225			u16 mode;
    226			unsigned type = DT_UNKNOWN;
    227
    228			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
    229				pr_err("small file entry\n");
    230				err = -EIO;
    231				goto out;
    232			}
    233
    234			mode = be16_to_cpu(entry.file.permissions.mode);
    235			if (S_ISREG(mode))
    236				type = DT_REG;
    237			else if (S_ISLNK(mode))
    238				type = DT_LNK;
    239			else if (S_ISFIFO(mode))
    240				type = DT_FIFO;
    241			else if (S_ISCHR(mode))
    242				type = DT_CHR;
    243			else if (S_ISBLK(mode))
    244				type = DT_BLK;
    245			else if (S_ISSOCK(mode))
    246				type = DT_SOCK;
    247
    248			if (!dir_emit(ctx, strbuf, len,
    249				      be32_to_cpu(entry.file.id), type))
    250				break;
    251		} else {
    252			pr_err("bad catalog entry type\n");
    253			err = -EIO;
    254			goto out;
    255		}
    256next:
    257		ctx->pos++;
    258		if (ctx->pos >= inode->i_size)
    259			goto out;
    260		err = hfs_brec_goto(&fd, 1);
    261		if (err)
    262			goto out;
    263	}
    264	rd = file->private_data;
    265	if (!rd) {
    266		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
    267		if (!rd) {
    268			err = -ENOMEM;
    269			goto out;
    270		}
    271		file->private_data = rd;
    272		rd->file = file;
    273		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
    274		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
    275		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
    276	}
    277	/*
    278	 * Can be done after the list insertion; exclusion with
    279	 * hfsplus_delete_cat() is provided by directory lock.
    280	 */
    281	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
    282out:
    283	kfree(strbuf);
    284	hfs_find_exit(&fd);
    285	return err;
    286}
    287
    288static int hfsplus_dir_release(struct inode *inode, struct file *file)
    289{
    290	struct hfsplus_readdir_data *rd = file->private_data;
    291	if (rd) {
    292		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
    293		list_del(&rd->list);
    294		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
    295		kfree(rd);
    296	}
    297	return 0;
    298}
    299
    300static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
    301			struct dentry *dst_dentry)
    302{
    303	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
    304	struct inode *inode = d_inode(src_dentry);
    305	struct inode *src_dir = d_inode(src_dentry->d_parent);
    306	struct qstr str;
    307	char name[32];
    308	u32 cnid, id;
    309	int res;
    310
    311	if (HFSPLUS_IS_RSRC(inode))
    312		return -EPERM;
    313	if (!S_ISREG(inode->i_mode))
    314		return -EPERM;
    315
    316	mutex_lock(&sbi->vh_mutex);
    317	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
    318		for (;;) {
    319			get_random_bytes(&id, sizeof(cnid));
    320			id &= 0x3fffffff;
    321			str.name = name;
    322			str.len = sprintf(name, "iNode%d", id);
    323			res = hfsplus_rename_cat(inode->i_ino,
    324						 src_dir, &src_dentry->d_name,
    325						 sbi->hidden_dir, &str);
    326			if (!res)
    327				break;
    328			if (res != -EEXIST)
    329				goto out;
    330		}
    331		HFSPLUS_I(inode)->linkid = id;
    332		cnid = sbi->next_cnid++;
    333		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
    334		res = hfsplus_create_cat(cnid, src_dir,
    335			&src_dentry->d_name, inode);
    336		if (res)
    337			/* panic? */
    338			goto out;
    339		sbi->file_count++;
    340	}
    341	cnid = sbi->next_cnid++;
    342	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
    343	if (res)
    344		goto out;
    345
    346	inc_nlink(inode);
    347	hfsplus_instantiate(dst_dentry, inode, cnid);
    348	ihold(inode);
    349	inode->i_ctime = current_time(inode);
    350	mark_inode_dirty(inode);
    351	sbi->file_count++;
    352	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
    353out:
    354	mutex_unlock(&sbi->vh_mutex);
    355	return res;
    356}
    357
    358static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
    359{
    360	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
    361	struct inode *inode = d_inode(dentry);
    362	struct qstr str;
    363	char name[32];
    364	u32 cnid;
    365	int res;
    366
    367	if (HFSPLUS_IS_RSRC(inode))
    368		return -EPERM;
    369
    370	mutex_lock(&sbi->vh_mutex);
    371	cnid = (u32)(unsigned long)dentry->d_fsdata;
    372	if (inode->i_ino == cnid &&
    373	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
    374		str.name = name;
    375		str.len = sprintf(name, "temp%lu", inode->i_ino);
    376		res = hfsplus_rename_cat(inode->i_ino,
    377					 dir, &dentry->d_name,
    378					 sbi->hidden_dir, &str);
    379		if (!res) {
    380			inode->i_flags |= S_DEAD;
    381			drop_nlink(inode);
    382		}
    383		goto out;
    384	}
    385	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
    386	if (res)
    387		goto out;
    388
    389	if (inode->i_nlink > 0)
    390		drop_nlink(inode);
    391	if (inode->i_ino == cnid)
    392		clear_nlink(inode);
    393	if (!inode->i_nlink) {
    394		if (inode->i_ino != cnid) {
    395			sbi->file_count--;
    396			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
    397				res = hfsplus_delete_cat(inode->i_ino,
    398							 sbi->hidden_dir,
    399							 NULL);
    400				if (!res)
    401					hfsplus_delete_inode(inode);
    402			} else
    403				inode->i_flags |= S_DEAD;
    404		} else
    405			hfsplus_delete_inode(inode);
    406	} else
    407		sbi->file_count--;
    408	inode->i_ctime = current_time(inode);
    409	mark_inode_dirty(inode);
    410out:
    411	mutex_unlock(&sbi->vh_mutex);
    412	return res;
    413}
    414
    415static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
    416{
    417	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
    418	struct inode *inode = d_inode(dentry);
    419	int res;
    420
    421	if (inode->i_size != 2)
    422		return -ENOTEMPTY;
    423
    424	mutex_lock(&sbi->vh_mutex);
    425	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
    426	if (res)
    427		goto out;
    428	clear_nlink(inode);
    429	inode->i_ctime = current_time(inode);
    430	hfsplus_delete_inode(inode);
    431	mark_inode_dirty(inode);
    432out:
    433	mutex_unlock(&sbi->vh_mutex);
    434	return res;
    435}
    436
    437static int hfsplus_symlink(struct user_namespace *mnt_userns, struct inode *dir,
    438			   struct dentry *dentry, const char *symname)
    439{
    440	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
    441	struct inode *inode;
    442	int res = -ENOMEM;
    443
    444	mutex_lock(&sbi->vh_mutex);
    445	inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
    446	if (!inode)
    447		goto out;
    448
    449	res = page_symlink(inode, symname, strlen(symname) + 1);
    450	if (res)
    451		goto out_err;
    452
    453	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
    454	if (res)
    455		goto out_err;
    456
    457	res = hfsplus_init_security(inode, dir, &dentry->d_name);
    458	if (res == -EOPNOTSUPP)
    459		res = 0; /* Operation is not supported. */
    460	else if (res) {
    461		/* Try to delete anyway without error analysis. */
    462		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
    463		goto out_err;
    464	}
    465
    466	hfsplus_instantiate(dentry, inode, inode->i_ino);
    467	mark_inode_dirty(inode);
    468	goto out;
    469
    470out_err:
    471	clear_nlink(inode);
    472	hfsplus_delete_inode(inode);
    473	iput(inode);
    474out:
    475	mutex_unlock(&sbi->vh_mutex);
    476	return res;
    477}
    478
    479static int hfsplus_mknod(struct user_namespace *mnt_userns, struct inode *dir,
    480			 struct dentry *dentry, umode_t mode, dev_t rdev)
    481{
    482	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
    483	struct inode *inode;
    484	int res = -ENOMEM;
    485
    486	mutex_lock(&sbi->vh_mutex);
    487	inode = hfsplus_new_inode(dir->i_sb, dir, mode);
    488	if (!inode)
    489		goto out;
    490
    491	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
    492		init_special_inode(inode, mode, rdev);
    493
    494	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
    495	if (res)
    496		goto failed_mknod;
    497
    498	res = hfsplus_init_security(inode, dir, &dentry->d_name);
    499	if (res == -EOPNOTSUPP)
    500		res = 0; /* Operation is not supported. */
    501	else if (res) {
    502		/* Try to delete anyway without error analysis. */
    503		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
    504		goto failed_mknod;
    505	}
    506
    507	hfsplus_instantiate(dentry, inode, inode->i_ino);
    508	mark_inode_dirty(inode);
    509	goto out;
    510
    511failed_mknod:
    512	clear_nlink(inode);
    513	hfsplus_delete_inode(inode);
    514	iput(inode);
    515out:
    516	mutex_unlock(&sbi->vh_mutex);
    517	return res;
    518}
    519
    520static int hfsplus_create(struct user_namespace *mnt_userns, struct inode *dir,
    521			  struct dentry *dentry, umode_t mode, bool excl)
    522{
    523	return hfsplus_mknod(&init_user_ns, dir, dentry, mode, 0);
    524}
    525
    526static int hfsplus_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
    527			 struct dentry *dentry, umode_t mode)
    528{
    529	return hfsplus_mknod(&init_user_ns, dir, dentry, mode | S_IFDIR, 0);
    530}
    531
    532static int hfsplus_rename(struct user_namespace *mnt_userns,
    533			  struct inode *old_dir, struct dentry *old_dentry,
    534			  struct inode *new_dir, struct dentry *new_dentry,
    535			  unsigned int flags)
    536{
    537	int res;
    538
    539	if (flags & ~RENAME_NOREPLACE)
    540		return -EINVAL;
    541
    542	/* Unlink destination if it already exists */
    543	if (d_really_is_positive(new_dentry)) {
    544		if (d_is_dir(new_dentry))
    545			res = hfsplus_rmdir(new_dir, new_dentry);
    546		else
    547			res = hfsplus_unlink(new_dir, new_dentry);
    548		if (res)
    549			return res;
    550	}
    551
    552	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
    553				 old_dir, &old_dentry->d_name,
    554				 new_dir, &new_dentry->d_name);
    555	if (!res)
    556		new_dentry->d_fsdata = old_dentry->d_fsdata;
    557	return res;
    558}
    559
    560const struct inode_operations hfsplus_dir_inode_operations = {
    561	.lookup			= hfsplus_lookup,
    562	.create			= hfsplus_create,
    563	.link			= hfsplus_link,
    564	.unlink			= hfsplus_unlink,
    565	.mkdir			= hfsplus_mkdir,
    566	.rmdir			= hfsplus_rmdir,
    567	.symlink		= hfsplus_symlink,
    568	.mknod			= hfsplus_mknod,
    569	.rename			= hfsplus_rename,
    570	.getattr		= hfsplus_getattr,
    571	.listxattr		= hfsplus_listxattr,
    572	.fileattr_get		= hfsplus_fileattr_get,
    573	.fileattr_set		= hfsplus_fileattr_set,
    574};
    575
    576const struct file_operations hfsplus_dir_operations = {
    577	.fsync		= hfsplus_file_fsync,
    578	.read		= generic_read_dir,
    579	.iterate_shared	= hfsplus_readdir,
    580	.unlocked_ioctl = hfsplus_ioctl,
    581	.llseek		= generic_file_llseek,
    582	.release	= hfsplus_dir_release,
    583};