[PATCH 1/9] LSM: Introduce inode_getsecid and ipc_getsecid hooks

Ahmed S. Darwish
2008-03-01T19:54:31Z

Introduce inode_getsecid(inode, secid) and ipc_getsecid(ipcp, secid)
LSM hooks. These hooks will be used instead of similar exported
SELinux interfaces.

Let {inode,ipc,task}_getsecid hooks set the secid to 0 by default
if CONFIG_SECURITY is not defined or if the hook is set to
NULL (dummy). This is done to notify the caller that no valid
secid exists.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
---

include/linux/security.h | 30 +++++++++++++++++++++++++++++-
security/dummy.c | 16 +++++++++++++++-
security/security.c | 10 ++++++++++
3 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index a33fd03..205a053 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -449,6 +449,11 @@ struct request_sock;
* @dentry is the dentry being changed.
* Return 0 on success. If error is returned, then the operation
* causing setuid bit removal is failed.
+ * @inode_getsecid:
+ * Get the secid associated with the node.
+ * @inode contains a pointer to the inode.
+ * @secid contains a pointer to the location where result will be saved.
+ * In case of failure, @secid will be set to zero.
*
* Security hooks for file operations
*
@@ -617,6 +622,8 @@ struct request_sock;
* @task_getsecid:
* Retrieve the security identifier of the process @p.
* @p contains the task_struct for the process and place is into @secid.
+ * In case of failure, @secid will be set to zero.
+ *
* @task_setgroups:
* Check permission before setting the supplementary group set of the
* current process.
@@ -989,6 +996,11 @@ struct request_sock;
* @ipcp contains the kernel IPC permission structure
* @flag contains the desired (requested) permission set
* Return 0 if permission is granted.
+ * @ipc_getsecid:
+ * Get the secid associated with the ipc object.
+ * @ipcp contains the kernel IPC permission structure.
+ * @secid contains a pointer to the location where result will be saved.
+ * In case of failure, @secid will be set to zero.
*
* Security hooks for individual messages held in System V IPC message queues
* @msg_msg_alloc_security:
@@ -1310,6 +1322,7 @@ struct security_operations {
int (*inode_getsecurity)(const struct inode *inode, const char *name, void **buffer, bool alloc);
int (*inode_setsecurity)(struct inode *inode, const char *name, const void *value, size_t size, int flags);
int (*inode_listsecurity)(struct inode *inode, char *buffer, size_t buffer_size);
+ void (*inode_getsecid)(const struct inode *inode, u32 *secid);

int (*file_permission) (struct file * file, int mask);
int (*file_alloc_security) (struct file * file);
@@ -1362,6 +1375,7 @@ struct security_operations {
void (*task_to_inode)(struct task_struct *p, struct inode *inode);

int (*ipc_permission) (struct kern_ipc_perm * ipcp, short flag);
+ void (*ipc_getsecid) (struct kern_ipc_perm *ipcp, u32 *secid);

int (*msg_msg_alloc_security) (struct msg_msg * msg);
void (*msg_msg_free_security) (struct msg_msg * msg);
@@ -1571,6 +1585,7 @@ int security_inode_killpriv(struct dentry *dentry);
int security_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc);
int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
+void security_inode_getsecid(const struct inode *inode, u32 *secid);
int security_file_permission(struct file *file, int mask);
int security_file_alloc(struct file *file);
void security_file_free(struct file *file);
@@ -1615,6 +1630,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
void security_task_reparent_to_init(struct task_struct *p);
void security_task_to_inode(struct task_struct *p, struct inode *inode);
int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
int security_msg_msg_alloc(struct msg_msg *msg);
void security_msg_msg_free(struct msg_msg *msg);
int security_msg_queue_alloc(struct msg_queue *msq);
@@ -1985,6 +2001,11 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
return 0;
}

+static inline void security_inode_getsecid(const struct inode *inode, u32 *secid)
+{
+ *secid = 0;
+}
+
static inline int security_file_permission (struct file *file, int mask)
{
return 0;
@@ -2100,7 +2121,9 @@ static inline int security_task_getsid (struct task_struct *p)
}

static inline void security_task_getsecid (struct task_struct *p, u32 *secid)
-{ }
+{
+ *secid = 0;
+}

static inline int security_task_setgroups (struct group_info *group_info)
{
@@ -2179,6 +2202,11 @@ static inline int security_ipc_permission (struct kern_ipc_perm *ipcp,
return 0;
}

+static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+{
+ *secid = 0;
+}
+
static inline int security_msg_msg_alloc (struct msg_msg * msg)
{
return 0;
diff --git a/security/dummy.c b/security/dummy.c
index 6a0056b..f5e5f95 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -422,6 +422,11 @@ static int dummy_inode_listsecurity(struct inode *inode, char *buffer, size_t bu
return 0;
}

+static void dummy_inode_getsecid(const struct inode *inode, u32 *secid)
+{
+ *secid = 0;
+}
+
static int dummy_file_permission (struct file *file, int mask)
{
return 0;
@@ -540,7 +545,9 @@ static int dummy_task_getsid (struct task_struct *p)
}

static void dummy_task_getsecid (struct task_struct *p, u32 *secid)
-{ }
+{
+ *secid = 0;
+}

static int dummy_task_setgroups (struct group_info *group_info)
{
@@ -614,6 +621,11 @@ static int dummy_ipc_permission (struct kern_ipc_perm *ipcp, short flag)
return 0;
}

+static void dummy_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+{
+ *secid = 0;
+}
+
static int dummy_msg_msg_alloc_security (struct msg_msg *msg)
{
return 0;
@@ -1062,6 +1074,7 @@ void security_fixup_ops (struct security_operations *ops)
set_to_dummy_if_null(ops, inode_getsecurity);
set_to_dummy_if_null(ops, inode_setsecurity);
set_to_dummy_if_null(ops, inode_listsecurity);
+ set_to_dummy_if_null(ops, inode_getsecid);
set_to_dummy_if_null(ops, file_permission);
set_to_dummy_if_null(ops, file_alloc_security);
set_to_dummy_if_null(ops, file_free_security);
@@ -1098,6 +1111,7 @@ void security_fixup_ops (struct security_operations *ops)
set_to_dummy_if_null(ops, task_reparent_to_init);
set_to_dummy_if_null(ops, task_to_inode);
set_to_dummy_if_null(ops, ipc_permission);
+ set_to_dummy_if_null(ops, ipc_getsecid);
set_to_dummy_if_null(ops, msg_msg_alloc_security);
set_to_dummy_if_null(ops, msg_msg_free_security);
set_to_dummy_if_null(ops, msg_queue_alloc_security);
diff --git a/security/security.c b/security/security.c
index 3e75b90..1748329 100644
--- a/security/security.c
+++ b/security/security.c
@@ -516,6 +516,11 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
return security_ops->inode_listsecurity(inode, buffer, buffer_size);
}

+void security_inode_getsecid(const struct inode *inode, u32 *secid)
+{
+ security_ops->inode_getsecid(inode, secid);
+}
+
int security_file_permission(struct file *file, int mask)
{
return security_ops->file_permission(file, mask);
@@ -705,6 +710,11 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
return security_ops->ipc_permission(ipcp, flag);
}

+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+{
+ security_ops->ipc_getsecid(ipcp, secid);
+}
+
int security_msg_msg_alloc(struct msg_msg *msg)
{
return security_ops->msg_msg_alloc_security(msg);

--

"Better to light a candle, than curse the darkness"

Ahmed S. Darwish
Homepage: http://darwish.07.googlepages.com
Blog: http://darwish-07.blogspot.com