[PATCH (for 3.15) 1/5] LSM: Pass the rename flags to each LSM module.
From: Tetsuo Handa
Date: Mon May 12 2014 - 09:22:57 EST
>From 579cfccf7ba49a53ff0f5fefe73f0b8dc618d878 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Date: Mon, 12 May 2014 21:05:52 +0900
Subject: [PATCH (for 3.15) 1/5] LSM: Pass the rename flags to each LSM module.
TOMOYO and AppArmor distinguish a directory's pathname and a non-directory's
pathname by whether the pathname ends with / character or not. Upon rename(),
they appended / character to the target dentry's pathname if the source
dentry's inode refers a directory, for the target dentry's inode will refer
a directory after successful rename(). This assumption was correct until
commit da1ce067 "vfs: add cross-rename" is introduced.
Commit da1ce067 changed security_{inode,path}_rename() to call LSM module
with reversed arguments if the rename flags contains RENAME_EXCHANGE. But
this is not sufficient for TOMOYO and AppArmor because RENAME_EXCHANGE
allows exchange of a directory's inode and a non-directory's inode. Also,
this is redundant for SMACK because there is no need to call
security_inode_rename() with reversed arguments.
To fix this regression, the rename flags needs to be passed to LSM module.
This patch is for allowing TOMOYO and AppArmor to handle RENAME_EXCHANGE
case differently, and for allowing SMACK to avoid needlessly checking
the same permission twice.
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Acked-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx> [smack]
---
include/linux/security.h | 8 ++++++--
security/apparmor/lsm.c | 3 ++-
security/capability.c | 6 ++++--
security/security.c | 10 ++++++----
security/selinux/hooks.c | 3 ++-
security/smack/smack_lsm.c | 4 +++-
security/tomoyo/tomoyo.c | 4 +++-
7 files changed, 26 insertions(+), 12 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 6478ce3..5158611 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -446,6 +446,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @old_dentry contains the dentry structure of the old link.
* @new_dir contains the inode structure for parent of the new link.
* @new_dentry contains the dentry structure of the new link.
+ * @flags contains rename flags.
* Return 0 if permission is granted.
* @path_rename:
* Check for permission to rename a file or directory.
@@ -453,6 +454,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @old_dentry contains the dentry structure of the old link.
* @new_dir contains the path structure for parent of the new link.
* @new_dentry contains the dentry structure of the new link.
+ * @flags contains rename flags.
* Return 0 if permission is granted.
* @path_chmod:
* Check for permission to change DAC's permission of a file or directory.
@@ -1492,7 +1494,8 @@ struct security_operations {
int (*path_link) (struct dentry *old_dentry, struct path *new_dir,
struct dentry *new_dentry);
int (*path_rename) (struct path *old_dir, struct dentry *old_dentry,
- struct path *new_dir, struct dentry *new_dentry);
+ struct path *new_dir, struct dentry *new_dentry,
+ unsigned int flags);
int (*path_chmod) (struct path *path, umode_t mode);
int (*path_chown) (struct path *path, kuid_t uid, kgid_t gid);
int (*path_chroot) (struct path *path);
@@ -1515,7 +1518,8 @@ struct security_operations {
int (*inode_mknod) (struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t dev);
int (*inode_rename) (struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry);
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags);
int (*inode_readlink) (struct dentry *dentry);
int (*inode_follow_link) (struct dentry *dentry, struct nameidata *nd);
int (*inode_permission) (struct inode *inode, int mask);
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 9981000..c0b4366 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -315,7 +315,8 @@ static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
}
static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
- struct path *new_dir, struct dentry *new_dentry)
+ struct path *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
{
struct aa_profile *profile;
int error = 0;
diff --git a/security/capability.c b/security/capability.c
index ad0d4de..620ba79 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -176,7 +176,8 @@ static int cap_inode_mknod(struct inode *inode, struct dentry *dentry,
}
static int cap_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
- struct inode *new_inode, struct dentry *new_dentry)
+ struct inode *new_inode, struct dentry *new_dentry,
+ unsigned int flags)
{
return 0;
}
@@ -280,7 +281,8 @@ static int cap_path_link(struct dentry *old_dentry, struct path *new_dir,
}
static int cap_path_rename(struct path *old_path, struct dentry *old_dentry,
- struct path *new_path, struct dentry *new_dentry)
+ struct path *new_path, struct dentry *new_dentry,
+ unsigned int flags)
{
return 0;
}
diff --git a/security/security.c b/security/security.c
index 8b774f3..81d7ffe 100644
--- a/security/security.c
+++ b/security/security.c
@@ -442,13 +442,14 @@ int security_path_rename(struct path *old_dir, struct dentry *old_dentry,
if (flags & RENAME_EXCHANGE) {
int err = security_ops->path_rename(new_dir, new_dentry,
- old_dir, old_dentry);
+ old_dir, old_dentry,
+ flags);
if (err)
return err;
}
return security_ops->path_rename(old_dir, old_dentry, new_dir,
- new_dentry);
+ new_dentry, flags);
}
EXPORT_SYMBOL(security_path_rename);
@@ -542,13 +543,14 @@ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry,
if (flags & RENAME_EXCHANGE) {
int err = security_ops->inode_rename(new_dir, new_dentry,
- old_dir, old_dentry);
+ old_dir, old_dentry,
+ flags);
if (err)
return err;
}
return security_ops->inode_rename(old_dir, old_dentry,
- new_dir, new_dentry);
+ new_dir, new_dentry, flags);
}
int security_inode_readlink(struct dentry *dentry)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 2c7341d..33f6f56 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2749,7 +2749,8 @@ static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t
}
static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
- struct inode *new_inode, struct dentry *new_dentry)
+ struct inode *new_inode, struct dentry *new_dentry,
+ unsigned int flags)
{
return may_rename(old_inode, old_dentry, new_inode, new_dentry);
}
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 14f52be..4c1933f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -697,6 +697,7 @@ static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
* @old_dentry: unused
* @new_inode: the new directory
* @new_dentry: unused
+ * @flags: unused
*
* Read and write access is required on both the old and
* new directories.
@@ -706,7 +707,8 @@ static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
static int smack_inode_rename(struct inode *old_inode,
struct dentry *old_dentry,
struct inode *new_inode,
- struct dentry *new_dentry)
+ struct dentry *new_dentry,
+ unsigned int flags)
{
int rc;
char *isp;
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index f0b756e..ac7dd97 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -287,13 +287,15 @@ static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
* @old_dentry: Pointer to "struct dentry".
* @new_parent: Pointer to "struct path".
* @new_dentry: Pointer to "struct dentry".
+ * @flags: Rename flags.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_rename(struct path *old_parent,
struct dentry *old_dentry,
struct path *new_parent,
- struct dentry *new_dentry)
+ struct dentry *new_dentry,
+ unsigned int flags)
{
struct path path1 = { old_parent->mnt, old_dentry };
struct path path2 = { new_parent->mnt, new_dentry };
--
1.7.1
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