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

[Paul Moore <paul.moore@hp.com>]

On Saturday 01 March 2008 2:51:09 pm Ahmed S. Darwish wrote:
> 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>

Reviewed-by: Paul Moore <paul.moore@hp.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);



-- 
paul moore
linux security @ hp