[PATCH 08/14] userns: Teach security_path_chown to take kuids and kgids

From: Eric W. Biederman
Date: Thu Sep 20 2012 - 20:29:38 EST


From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>

Don't make the security modules deal with raw user space uid and
gids instead pass in a kuid_t and a kgid_t so that security modules
only have to deal with internal kernel uids and gids.

Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: James Morris <james.l.morris@xxxxxxxxxx>
Cc: John Johansen <john.johansen@xxxxxxxxxxxxx>
Cc: Kentaro Takeda <takedakn@xxxxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Acked-by: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
fs/open.c | 2 +-
include/linux/security.h | 6 +++---
security/apparmor/lsm.c | 2 +-
security/capability.c | 2 +-
security/security.c | 2 +-
security/tomoyo/tomoyo.c | 12 +++++++-----
6 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index f3d96e7..2b25739 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -534,7 +534,7 @@ static int chown_common(struct path *path, uid_t user, gid_t group)
newattrs.ia_valid |=
ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
mutex_lock(&inode->i_mutex);
- error = security_path_chown(path, user, group);
+ error = security_path_chown(path, uid, gid);
if (!error)
error = notify_change(path->dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
diff --git a/include/linux/security.h b/include/linux/security.h
index 4e5a73c..ebb92cb 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1437,7 +1437,7 @@ struct security_operations {
int (*path_rename) (struct path *old_dir, struct dentry *old_dentry,
struct path *new_dir, struct dentry *new_dentry);
int (*path_chmod) (struct path *path, umode_t mode);
- int (*path_chown) (struct path *path, uid_t uid, gid_t gid);
+ int (*path_chown) (struct path *path, kuid_t uid, kgid_t gid);
int (*path_chroot) (struct path *path);
#endif

@@ -2832,7 +2832,7 @@ int security_path_link(struct dentry *old_dentry, struct path *new_dir,
int security_path_rename(struct path *old_dir, struct dentry *old_dentry,
struct path *new_dir, struct dentry *new_dentry);
int security_path_chmod(struct path *path, umode_t mode);
-int security_path_chown(struct path *path, uid_t uid, gid_t gid);
+int security_path_chown(struct path *path, kuid_t uid, kgid_t gid);
int security_path_chroot(struct path *path);
#else /* CONFIG_SECURITY_PATH */
static inline int security_path_unlink(struct path *dir, struct dentry *dentry)
@@ -2888,7 +2888,7 @@ static inline int security_path_chmod(struct path *path, umode_t mode)
return 0;
}

-static inline int security_path_chown(struct path *path, uid_t uid, gid_t gid)
+static inline int security_path_chown(struct path *path, kuid_t uid, kgid_t gid)
{
return 0;
}
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 8ea39aa..8c2a7f6 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -352,7 +352,7 @@ static int apparmor_path_chmod(struct path *path, umode_t mode)
return common_perm_mnt_dentry(OP_CHMOD, path->mnt, path->dentry, AA_MAY_CHMOD);
}

-static int apparmor_path_chown(struct path *path, uid_t uid, gid_t gid)
+static int apparmor_path_chown(struct path *path, kuid_t uid, kgid_t gid)
{
struct path_cond cond = { path->dentry->d_inode->i_uid,
path->dentry->d_inode->i_mode
diff --git a/security/capability.c b/security/capability.c
index 61095df..a40aac6 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -284,7 +284,7 @@ static int cap_path_chmod(struct path *path, umode_t mode)
return 0;
}

-static int cap_path_chown(struct path *path, uid_t uid, gid_t gid)
+static int cap_path_chown(struct path *path, kuid_t uid, kgid_t gid)
{
return 0;
}
diff --git a/security/security.c b/security/security.c
index 860aeb3..f9a2f2e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -434,7 +434,7 @@ int security_path_chmod(struct path *path, umode_t mode)
return security_ops->path_chmod(path, mode);
}

-int security_path_chown(struct path *path, uid_t uid, gid_t gid)
+int security_path_chown(struct path *path, kuid_t uid, kgid_t gid)
{
if (unlikely(IS_PRIVATE(path->dentry->d_inode)))
return 0;
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index c2d04a5..d88eb3a 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -373,13 +373,15 @@ static int tomoyo_path_chmod(struct path *path, umode_t mode)
*
* Returns 0 on success, negative value otherwise.
*/
-static int tomoyo_path_chown(struct path *path, uid_t uid, gid_t gid)
+static int tomoyo_path_chown(struct path *path, kuid_t uid, kgid_t gid)
{
int error = 0;
- if (uid != (uid_t) -1)
- error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path, uid);
- if (!error && gid != (gid_t) -1)
- error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path, gid);
+ if (uid_valid(uid))
+ error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path,
+ from_kuid(&init_user_ns, uid));
+ if (!error && gid_valid(gid))
+ error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path,
+ from_kgid(&init_user_ns, gid));
return error;
}

--
1.7.5.4

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