Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
kernel-fxtec-pro1x/fs/f2fs/acl.c
Jaegeuk Kim 2ed2d5b33c f2fs: fix a deadlock during init_acl procedure 
The deadlock is found through the following scenario.

sys_mkdir()
 -> f2fs_add_link()
  -> __f2fs_add_link()
   -> init_inode_metadata()
     : lock_page(inode);
    -> f2fs_init_acl()
     -> f2fs_set_acl()
      -> f2fs_setxattr(..., NULL)
       : This NULL page incurs a deadlock at update_inode_page().

So, likewise f2fs_init_security(), this patch adds a parameter to transfer the
locked inode page to f2fs_setxattr().

Found by Linux File System Verification project (linuxtesting.org).

Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-10-28 13:39:09 +09:00

414 lines
9.5 KiB
C
Raw Blame History

/*
* fs/f2fs/acl.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Portions of this code from linux/fs/ext2/acl.c
*
* Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/f2fs_fs.h>
#include "f2fs.h"
#include "xattr.h"
#include "acl.h"
#define get_inode_mode(i) ((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
(F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
static inline size_t f2fs_acl_size(int count)
{
if (count <= 4) {
return sizeof(struct f2fs_acl_header) +
count * sizeof(struct f2fs_acl_entry_short);
} else {
return sizeof(struct f2fs_acl_header) +
4 * sizeof(struct f2fs_acl_entry_short) +
(count - 4) * sizeof(struct f2fs_acl_entry);
}
}
static inline int f2fs_acl_count(size_t size)
{
ssize_t s;
size -= sizeof(struct f2fs_acl_header);
s = size - 4 * sizeof(struct f2fs_acl_entry_short);
if (s < 0) {
if (size % sizeof(struct f2fs_acl_entry_short))
return -1;
return size / sizeof(struct f2fs_acl_entry_short);
} else {
if (s % sizeof(struct f2fs_acl_entry))
return -1;
return s / sizeof(struct f2fs_acl_entry) + 4;
}
}
static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
{
int i, count;
struct posix_acl *acl;
struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
const char *end = value + size;
if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
return ERR_PTR(-EINVAL);
count = f2fs_acl_count(size);
if (count < 0)
return ERR_PTR(-EINVAL);
if (count == 0)
return NULL;
acl = posix_acl_alloc(count, GFP_KERNEL);
if (!acl)
return ERR_PTR(-ENOMEM);
for (i = 0; i < count; i++) {
if ((char *)entry > end)
goto fail;
acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
switch (acl->a_entries[i].e_tag) {
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry_short));
break;
case ACL_USER:
acl->a_entries[i].e_uid =
make_kuid(&init_user_ns,
le32_to_cpu(entry->e_id));
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry));
break;
case ACL_GROUP:
acl->a_entries[i].e_gid =
make_kgid(&init_user_ns,
le32_to_cpu(entry->e_id));
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry));
break;
default:
goto fail;
}
}
if ((char *)entry != end)
goto fail;
return acl;
fail:
posix_acl_release(acl);
return ERR_PTR(-EINVAL);
}
static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
{
struct f2fs_acl_header *f2fs_acl;
struct f2fs_acl_entry *entry;
int i;
f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
sizeof(struct f2fs_acl_entry), GFP_KERNEL);
if (!f2fs_acl)
return ERR_PTR(-ENOMEM);
f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
for (i = 0; i < acl->a_count; i++) {
entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
switch (acl->a_entries[i].e_tag) {
case ACL_USER:
entry->e_id = cpu_to_le32(
from_kuid(&init_user_ns,
acl->a_entries[i].e_uid));
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry));
break;
case ACL_GROUP:
entry->e_id = cpu_to_le32(
from_kgid(&init_user_ns,
acl->a_entries[i].e_gid));
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry));
break;
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry_short));
break;
default:
goto fail;
}
}
*size = f2fs_acl_size(acl->a_count);
return (void *)f2fs_acl;
fail:
kfree(f2fs_acl);
return ERR_PTR(-EINVAL);
}
struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
void *value = NULL;
struct posix_acl *acl;
int retval;
if (!test_opt(sbi, POSIX_ACL))
return NULL;
acl = get_cached_acl(inode, type);
if (acl != ACL_NOT_CACHED)
return acl;
if (type == ACL_TYPE_ACCESS)
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
if (retval > 0) {
value = kmalloc(retval, GFP_KERNEL);
if (!value)
return ERR_PTR(-ENOMEM);
retval = f2fs_getxattr(inode, name_index, "", value, retval);
}
if (retval > 0)
acl = f2fs_acl_from_disk(value, retval);
else if (retval == -ENODATA)
acl = NULL;
else
acl = ERR_PTR(retval);
kfree(value);
if (!IS_ERR(acl))
set_cached_acl(inode, type, acl);
return acl;
}
static int f2fs_set_acl(struct inode *inode, int type,
struct posix_acl *acl, struct page *ipage)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
int name_index;
void *value = NULL;
size_t size = 0;
int error;
if (!test_opt(sbi, POSIX_ACL))
return 0;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
switch (type) {
case ACL_TYPE_ACCESS:
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl) {
error = posix_acl_equiv_mode(acl, &inode->i_mode);
if (error < 0)
return error;
set_acl_inode(fi, inode->i_mode);
if (error == 0)
acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
if (!S_ISDIR(inode->i_mode))
return acl ? -EACCES : 0;
break;
default:
return -EINVAL;
}
if (acl) {
value = f2fs_acl_to_disk(acl, &size);
if (IS_ERR(value)) {
cond_clear_inode_flag(fi, FI_ACL_MODE);
return (int)PTR_ERR(value);
}
}
error = f2fs_setxattr(inode, name_index, "", value, size, ipage);
kfree(value);
if (!error)
set_cached_acl(inode, type, acl);
cond_clear_inode_flag(fi, FI_ACL_MODE);
return error;
}
int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct posix_acl *acl = NULL;
int error = 0;
if (!S_ISLNK(inode->i_mode)) {
if (test_opt(sbi, POSIX_ACL)) {
acl = f2fs_get_acl(dir, ACL_TYPE_DEFAULT);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
if (!acl)
inode->i_mode &= ~current_umask();
}
if (!test_opt(sbi, POSIX_ACL) || !acl)
goto cleanup;
if (S_ISDIR(inode->i_mode)) {
error = f2fs_set_acl(inode, ACL_TYPE_DEFAULT, acl, ipage);
if (error)
goto cleanup;
}
error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
if (error < 0)
return error;
if (error > 0)
error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, ipage);
cleanup:
posix_acl_release(acl);
return error;
}
int f2fs_acl_chmod(struct inode *inode)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct posix_acl *acl;
int error;
umode_t mode = get_inode_mode(inode);
if (!test_opt(sbi, POSIX_ACL))
return 0;
if (S_ISLNK(mode))
return -EOPNOTSUPP;
acl = f2fs_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl) || !acl)
return PTR_ERR(acl);
error = posix_acl_chmod(&acl, GFP_KERNEL, mode);
if (error)
return error;
error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, NULL);
posix_acl_release(acl);
return error;
}
static size_t f2fs_xattr_list_acl(struct dentry *dentry, char *list,
size_t list_size, const char *name, size_t name_len, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
const char *xname = POSIX_ACL_XATTR_DEFAULT;
size_t size;
if (!test_opt(sbi, POSIX_ACL))
return 0;
if (type == ACL_TYPE_ACCESS)
xname = POSIX_ACL_XATTR_ACCESS;
size = strlen(xname) + 1;
if (list && size <= list_size)
memcpy(list, xname, size);
return size;
}
static int f2fs_xattr_get_acl(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
struct posix_acl *acl;
int error;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!test_opt(sbi, POSIX_ACL))
return -EOPNOTSUPP;
acl = f2fs_get_acl(dentry->d_inode, type);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (!acl)
return -ENODATA;
error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
posix_acl_release(acl);
return error;
}
static int f2fs_xattr_set_acl(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
struct inode *inode = dentry->d_inode;
struct posix_acl *acl = NULL;
int error;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!test_opt(sbi, POSIX_ACL))
return -EOPNOTSUPP;
if (!inode_owner_or_capable(inode))
return -EPERM;
if (value) {
acl = posix_acl_from_xattr(&init_user_ns, value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
error = posix_acl_valid(acl);
if (error)
goto release_and_out;
}
} else {
acl = NULL;
}
error = f2fs_set_acl(inode, type, acl, NULL);
release_and_out:
posix_acl_release(acl);
return error;
}
const struct xattr_handler f2fs_xattr_acl_default_handler = {
.prefix = POSIX_ACL_XATTR_DEFAULT,
.flags = ACL_TYPE_DEFAULT,
.list = f2fs_xattr_list_acl,
.get = f2fs_xattr_get_acl,
.set = f2fs_xattr_set_acl,
};
const struct xattr_handler f2fs_xattr_acl_access_handler = {
.prefix = POSIX_ACL_XATTR_ACCESS,
.flags = ACL_TYPE_ACCESS,
.list = f2fs_xattr_list_acl,
.get = f2fs_xattr_get_acl,
.set = f2fs_xattr_set_acl,
};
Reference in a new issue View git blame Copy permalink