| 1 |
/* |
| 2 |
* include/linux/tomoyo_vfs.h |
| 3 |
* |
| 4 |
* Implementation of the Domain-Based Mandatory Access Control. |
| 5 |
* |
| 6 |
* Copyright (C) 2005-2008 NTT DATA CORPORATION |
| 7 |
* |
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* Version: 1.6.3-pre 2008/07/10 |
| 9 |
* |
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* This file is applicable to both 2.4.30 and 2.6.11 and later. |
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* See README.ccs for ChangeLog. |
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* |
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*/ |
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|
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#ifndef _LINUX_TOMOYO_VFS_H |
| 16 |
#define _LINUX_TOMOYO_VFS_H |
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|
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#include <linux/version.h> |
| 19 |
|
| 20 |
/* |
| 21 |
* This file contains copy of some of VFS helper functions. |
| 22 |
* |
| 23 |
* Since TOMOYO Linux requires "struct vfsmount" parameter to calculate |
| 24 |
* an absolute pathname of the requested "struct dentry" parameter |
| 25 |
* but the VFS helper functions don't receive "struct vfsmount" parameter, |
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* TOMOYO Linux checks permission outside VFS helper functions. |
| 27 |
* To keep the DAC's permission checks are performed before the |
| 28 |
* TOMOYO Linux's permission checks are performed, I'm manually inserting |
| 29 |
* these functions that performs the DAC's permission checks into fs/namei.c. |
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* |
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* The approach to obtain "struct vfsmount" parameter from |
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* the "struct task_struct" doesn't work because it triggers deadlock. |
| 33 |
*/ |
| 34 |
|
| 35 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 5, 0) |
| 36 |
|
| 37 |
/* Some of permission checks from vfs_create(). */ |
| 38 |
static inline int pre_vfs_create(struct inode *dir, struct dentry *dentry) |
| 39 |
{ |
| 40 |
int error; |
| 41 |
down(&dir->i_zombie); |
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error = may_create(dir, dentry); |
| 43 |
if (!error && (!dir->i_op || !dir->i_op->create)) |
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error = -EACCES; |
| 45 |
up(&dir->i_zombie); |
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return error; |
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} |
| 48 |
|
| 49 |
/* |
| 50 |
* Some of permission checks from vfs_mknod(). |
| 51 |
* |
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* This function is exported because |
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* vfs_mknod() is called from net/unix/af_unix.c. |
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*/ |
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int pre_vfs_mknod(struct inode *dir, struct dentry *dentry) |
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{ |
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int error; |
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down(&dir->i_zombie); |
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error = may_create(dir, dentry); |
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if (!error && (!dir->i_op || !dir->i_op->mknod)) |
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error = -EPERM; |
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up(&dir->i_zombie); |
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return error; |
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} |
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EXPORT_SYMBOL(pre_vfs_mknod); |
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|
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/* Some of permission checks from vfs_mkdir(). */ |
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static inline int pre_vfs_mkdir(struct inode *dir, struct dentry *dentry) |
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{ |
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int error; |
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down(&dir->i_zombie); |
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error = may_create(dir, dentry); |
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if (!error && (!dir->i_op || !dir->i_op->mkdir)) |
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error = -EPERM; |
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up(&dir->i_zombie); |
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return error; |
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} |
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|
| 79 |
/* Some of permission checks from vfs_rmdir(). */ |
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static inline int pre_vfs_rmdir(struct inode *dir, struct dentry *dentry) |
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{ |
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int error = may_delete(dir, dentry, 1); |
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if (!error && (!dir->i_op || !dir->i_op->rmdir)) |
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error = -EPERM; |
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return error; |
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} |
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|
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/* Some of permission checks from vfs_unlink(). */ |
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static inline int pre_vfs_unlink(struct inode *dir, struct dentry *dentry) |
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{ |
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#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 4, 33) |
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int error; |
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down(&dir->i_zombie); |
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error = may_delete(dir, dentry, 0); |
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if (!error && (!dir->i_op || !dir->i_op->unlink)) |
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error = -EPERM; |
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up(&dir->i_zombie); |
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return error; |
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#else |
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int error; |
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struct inode *inode; |
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error = may_delete(dir, dentry, 0); |
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if (error) |
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return error; |
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inode = dentry->d_inode; |
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atomic_inc(&inode->i_count); |
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double_down(&dir->i_zombie, &inode->i_zombie); |
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error = -EPERM; |
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if (dir->i_op && dir->i_op->unlink) |
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error = 0; |
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double_up(&dir->i_zombie, &inode->i_zombie); |
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iput(inode); |
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return error; |
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#endif |
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} |
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|
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/* Permission checks from vfs_symlink(). */ |
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static inline int pre_vfs_symlink(struct inode *dir, struct dentry *dentry) |
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{ |
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int error; |
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down(&dir->i_zombie); |
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error = may_create(dir, dentry); |
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if (error) |
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goto exit_lock; |
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if (!dir->i_op || !dir->i_op->symlink) |
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error = -EPERM; |
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exit_lock: |
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up(&dir->i_zombie); |
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return error; |
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} |
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|
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/* Some of permission checks from vfs_link(). */ |
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static inline int pre_vfs_link(struct dentry *old_dentry, struct inode *dir, |
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struct dentry *new_dentry) |
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{ |
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#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 4, 33) |
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struct inode *inode; |
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int error; |
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down(&dir->i_zombie); |
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error = -ENOENT; |
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inode = old_dentry->d_inode; |
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if (!inode) |
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goto exit_lock; |
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error = may_create(dir, new_dentry); |
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if (error) |
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goto exit_lock; |
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error = -EXDEV; |
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if (dir->i_dev != inode->i_dev) |
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goto exit_lock; |
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error = -EPERM; |
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if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) |
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goto exit_lock; |
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if (!dir->i_op || !dir->i_op->link) |
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goto exit_lock; |
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error = 0; |
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exit_lock: |
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up(&dir->i_zombie); |
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return error; |
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#else |
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struct inode *inode; |
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int error; |
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error = -ENOENT; |
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inode = old_dentry->d_inode; |
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if (!inode) |
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goto exit; |
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error = -EXDEV; |
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if (dir->i_dev != inode->i_dev) |
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goto exit; |
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double_down(&dir->i_zombie, &old_dentry->d_inode->i_zombie); |
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error = may_create(dir, new_dentry); |
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if (error) |
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goto exit_lock; |
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error = -EPERM; |
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if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) |
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goto exit_lock; |
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if (!dir->i_op || !dir->i_op->link) |
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goto exit_lock; |
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error = 0; |
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exit_lock: |
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double_up(&dir->i_zombie, &old_dentry->d_inode->i_zombie); |
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exit: |
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return error; |
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#endif |
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} |
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|
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/* Some of permission checks from vfs_rename_dir(). */ |
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static inline int pre_vfs_rename_dir(struct inode *old_dir, |
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struct dentry *old_dentry, |
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struct inode *new_dir, |
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struct dentry *new_dentry) |
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{ |
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int error; |
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if (old_dentry->d_inode == new_dentry->d_inode) |
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return 0; |
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error = may_delete(old_dir, old_dentry, 1); |
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if (error) |
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return error; |
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if (new_dir->i_dev != old_dir->i_dev) |
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return -EXDEV; |
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if (!new_dentry->d_inode) |
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error = may_create(new_dir, new_dentry); |
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else |
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error = may_delete(new_dir, new_dentry, 1); |
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if (error) |
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return error; |
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if (!old_dir->i_op || !old_dir->i_op->rename) |
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return -EPERM; |
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if (new_dir != old_dir) |
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error = permission(old_dentry->d_inode, MAY_WRITE); |
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return error; |
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} |
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|
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/* Some of permission checks from vfs_rename_other(). */ |
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static inline int pre_vfs_rename_other(struct inode *old_dir, |
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struct dentry *old_dentry, |
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struct inode *new_dir, |
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struct dentry *new_dentry) |
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{ |
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int error; |
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if (old_dentry->d_inode == new_dentry->d_inode) |
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return 0; |
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error = may_delete(old_dir, old_dentry, 0); |
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if (error) |
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return error; |
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if (new_dir->i_dev != old_dir->i_dev) |
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return -EXDEV; |
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if (!new_dentry->d_inode) |
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error = may_create(new_dir, new_dentry); |
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else |
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error = may_delete(new_dir, new_dentry, 0); |
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if (error) |
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return error; |
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if (!old_dir->i_op || !old_dir->i_op->rename) |
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return -EPERM; |
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return 0; |
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} |
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|
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/* Some of permission checks from vfs_rename(). */ |
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static inline int pre_vfs_rename(struct inode *old_dir, |
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struct dentry *old_dentry, |
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struct inode *new_dir, |
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struct dentry *new_dentry) |
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{ |
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int error; |
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lock_kernel(); /* From do_rename(). */ |
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if (S_ISDIR(old_dentry->d_inode->i_mode)) |
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error = pre_vfs_rename_dir(old_dir, old_dentry, |
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new_dir, new_dentry); |
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else |
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error = pre_vfs_rename_other(old_dir, old_dentry, |
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new_dir, new_dentry); |
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unlock_kernel(); /* From do_rename(). */ |
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return error; |
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} |
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|
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#else |
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|
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/* |
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* Permission checks before security_inode_mknod() is called. |
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* |
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* This function is exported because |
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* vfs_mknod() is called from net/unix/af_unix.c. |
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*/ |
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int pre_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode) |
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{ |
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int error = may_create(dir, dentry, NULL); |
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if (error) |
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return error; |
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if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD)) |
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return -EPERM; |
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if (!dir->i_op || !dir->i_op->mknod) |
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return -EPERM; |
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return 0; |
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} |
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EXPORT_SYMBOL(pre_vfs_mknod); |
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|
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/* Permission checks before security_inode_mkdir() is called. */ |
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static inline int pre_vfs_mkdir(struct inode *dir, struct dentry *dentry) |
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{ |
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int error = may_create(dir, dentry, NULL); |
| 281 |
if (error) |
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return error; |
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if (!dir->i_op || !dir->i_op->mkdir) |
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return -EPERM; |
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return 0; |
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} |
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|
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/* Some of permission checks before security_inode_rmdir() is called. */ |
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static inline int pre_vfs_rmdir(struct inode *dir, struct dentry *dentry) |
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{ |
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int error = may_delete(dir, dentry, 1); |
| 292 |
if (error) |
| 293 |
return error; |
| 294 |
if (!dir->i_op || !dir->i_op->rmdir) |
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return -EPERM; |
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return 0; |
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} |
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|
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/* Some of permission checks before security_inode_unlink() is called. */ |
| 300 |
static inline int pre_vfs_unlink(struct inode *dir, struct dentry *dentry) |
| 301 |
{ |
| 302 |
int error = may_delete(dir, dentry, 0); |
| 303 |
if (error) |
| 304 |
return error; |
| 305 |
if (!dir->i_op || !dir->i_op->unlink) |
| 306 |
return -EPERM; |
| 307 |
return 0; |
| 308 |
} |
| 309 |
|
| 310 |
/* Permission checks before security_inode_link() is called. */ |
| 311 |
static inline int pre_vfs_link(struct dentry *old_dentry, struct inode *dir, |
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struct dentry *new_dentry) |
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{ |
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struct inode *inode = old_dentry->d_inode; |
| 315 |
int error; |
| 316 |
if (!inode) |
| 317 |
return -ENOENT; |
| 318 |
error = may_create(dir, new_dentry, NULL); |
| 319 |
if (error) |
| 320 |
return error; |
| 321 |
if (dir->i_sb != inode->i_sb) |
| 322 |
return -EXDEV; |
| 323 |
if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) |
| 324 |
return -EPERM; |
| 325 |
if (!dir->i_op || !dir->i_op->link) |
| 326 |
return -EPERM; |
| 327 |
if (S_ISDIR(old_dentry->d_inode->i_mode)) |
| 328 |
return -EPERM; |
| 329 |
return 0; |
| 330 |
} |
| 331 |
|
| 332 |
/* Permission checks before security_inode_symlink() is called. */ |
| 333 |
static inline int pre_vfs_symlink(struct inode *dir, struct dentry *dentry) |
| 334 |
{ |
| 335 |
int error = may_create(dir, dentry, NULL); |
| 336 |
if (error) |
| 337 |
return error; |
| 338 |
if (!dir->i_op || !dir->i_op->symlink) |
| 339 |
return -EPERM; |
| 340 |
return 0; |
| 341 |
} |
| 342 |
|
| 343 |
/* Permission checks before security_inode_rename() is called. */ |
| 344 |
static inline int pre_vfs_rename(struct inode *old_dir, |
| 345 |
struct dentry *old_dentry, |
| 346 |
struct inode *new_dir, |
| 347 |
struct dentry *new_dentry) |
| 348 |
{ |
| 349 |
int error; |
| 350 |
const int is_dir = S_ISDIR(old_dentry->d_inode->i_mode); |
| 351 |
if (old_dentry->d_inode == new_dentry->d_inode) |
| 352 |
return 0; |
| 353 |
error = may_delete(old_dir, old_dentry, is_dir); |
| 354 |
if (error) |
| 355 |
return error; |
| 356 |
if (!new_dentry->d_inode) |
| 357 |
error = may_create(new_dir, new_dentry, NULL); |
| 358 |
else |
| 359 |
error = may_delete(new_dir, new_dentry, is_dir); |
| 360 |
if (error) |
| 361 |
return error; |
| 362 |
if (!old_dir->i_op || !old_dir->i_op->rename) |
| 363 |
return -EPERM; |
| 364 |
if (is_dir && new_dir != old_dir) |
| 365 |
error = permission(old_dentry->d_inode, MAY_WRITE, NULL); |
| 366 |
return error; |
| 367 |
} |
| 368 |
|
| 369 |
#endif |
| 370 |
|
| 371 |
#endif |
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