-/* Credentials management
+/* Credentials management - see Documentation/credentials.txt
*
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
#define _LINUX_CRED_H
#include <linux/capability.h>
+#include <linux/init.h>
#include <linux/key.h>
+#include <linux/selinux.h>
#include <asm/atomic.h>
struct user_struct;
struct cred;
+struct inode;
/*
* COW Supplementary groups list
} while (0)
extern struct group_info *groups_alloc(int);
+extern struct group_info init_groups;
extern void groups_free(struct group_info *);
extern int set_current_groups(struct group_info *);
extern int set_groups(struct cred *, struct group_info *);
*/
struct cred {
atomic_t usage;
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ atomic_t subscribers; /* number of processes subscribed */
+ void *put_addr;
+ unsigned magic;
+#define CRED_MAGIC 0x43736564
+#define CRED_MAGIC_DEAD 0x44656144
+#endif
uid_t uid; /* real UID of the task */
gid_t gid; /* real GID of the task */
uid_t suid; /* saved UID of the task */
};
extern void __put_cred(struct cred *);
+extern void exit_creds(struct task_struct *);
extern int copy_creds(struct task_struct *, unsigned long);
+extern struct cred *cred_alloc_blank(void);
extern struct cred *prepare_creds(void);
extern struct cred *prepare_exec_creds(void);
extern struct cred *prepare_usermodehelper_creds(void);
extern int commit_creds(struct cred *);
extern void abort_creds(struct cred *);
-extern const struct cred *override_creds(const struct cred *) __deprecated;
-extern void revert_creds(const struct cred *) __deprecated;
+extern const struct cred *override_creds(const struct cred *);
+extern void revert_creds(const struct cred *);
+extern struct cred *prepare_kernel_cred(struct task_struct *);
+extern int change_create_files_as(struct cred *, struct inode *);
+extern int set_security_override(struct cred *, u32);
+extern int set_security_override_from_ctx(struct cred *, const char *);
+extern int set_create_files_as(struct cred *, struct inode *);
extern void __init cred_init(void);
+/*
+ * check for validity of credentials
+ */
+#ifdef CONFIG_DEBUG_CREDENTIALS
+extern void __invalid_creds(const struct cred *, const char *, unsigned);
+extern void __validate_process_creds(struct task_struct *,
+ const char *, unsigned);
+
+extern bool creds_are_invalid(const struct cred *cred);
+
+static inline void __validate_creds(const struct cred *cred,
+ const char *file, unsigned line)
+{
+ if (unlikely(creds_are_invalid(cred)))
+ __invalid_creds(cred, file, line);
+}
+
+#define validate_creds(cred) \
+do { \
+ __validate_creds((cred), __FILE__, __LINE__); \
+} while(0)
+
+#define validate_process_creds() \
+do { \
+ __validate_process_creds(current, __FILE__, __LINE__); \
+} while(0)
+
+extern void validate_creds_for_do_exit(struct task_struct *);
+#else
+static inline void validate_creds(const struct cred *cred)
+{
+}
+static inline void validate_creds_for_do_exit(struct task_struct *tsk)
+{
+}
+static inline void validate_process_creds(void)
+{
+}
+#endif
+
/**
* get_new_cred - Get a reference on a new set of credentials
* @cred: The new credentials to reference
*
* Get a reference on the specified set of credentials. The caller must
* release the reference.
+ *
+ * This is used to deal with a committed set of credentials. Although the
+ * pointer is const, this will temporarily discard the const and increment the
+ * usage count. The purpose of this is to attempt to catch at compile time the
+ * accidental alteration of a set of credentials that should be considered
+ * immutable.
*/
static inline const struct cred *get_cred(const struct cred *cred)
{
- return get_new_cred((struct cred *) cred);
+ struct cred *nonconst_cred = (struct cred *) cred;
+ validate_creds(cred);
+ return get_new_cred(nonconst_cred);
}
/**
*
* Release a reference to a set of credentials, deleting them when the last ref
* is released.
+ *
+ * This takes a const pointer to a set of credentials because the credentials
+ * on task_struct are attached by const pointers to prevent accidental
+ * alteration of otherwise immutable credential sets.
*/
static inline void put_cred(const struct cred *_cred)
{
struct cred *cred = (struct cred *) _cred;
- BUG_ON(atomic_read(&(cred)->usage) <= 0);
+ validate_creds(cred);
if (atomic_dec_and_test(&(cred)->usage))
__put_cred(cred);
}
/**
- * current_cred - Access the current task's credentials
+ * current_cred - Access the current task's subjective credentials
*
- * Access the credentials of the current task.
+ * Access the subjective credentials of the current task.
*/
#define current_cred() \
(current->cred)
/**
- * __task_cred - Access another task's credentials
+ * __task_cred - Access a task's objective credentials
* @task: The task to query
*
- * Access the credentials of another task. The caller must hold the
- * RCU readlock.
+ * Access the objective credentials of a task. The caller must hold the RCU
+ * readlock.
*
* The caller must make sure task doesn't go away, either by holding a ref on
* task or by holding tasklist_lock to prevent it from being unlinked.
*/
#define __task_cred(task) \
- ((const struct cred *)(rcu_dereference((task)->cred)))
+ ((const struct cred *)(rcu_dereference((task)->real_cred)))
/**
- * get_task_cred - Get another task's credentials
+ * get_task_cred - Get another task's objective credentials
* @task: The task to query
*
- * Get the credentials of a task, pinning them so that they can't go away.
- * Accessing a task's credentials directly is not permitted.
+ * Get the objective credentials of a task, pinning them so that they can't go
+ * away. Accessing a task's credentials directly is not permitted.
*
* The caller must make sure task doesn't go away, either by holding a ref on
* task or by holding tasklist_lock to prevent it from being unlinked.
})
/**
- * get_current_cred - Get the current task's credentials
+ * get_current_cred - Get the current task's subjective credentials
*
- * Get the credentials of the current task, pinning them so that they can't go
- * away. Accessing the current task's credentials directly is not permitted.
+ * Get the subjective credentials of the current task, pinning them so that
+ * they can't go away. Accessing the current task's credentials directly is
+ * not permitted.
*/
#define get_current_cred() \
(get_cred(current_cred()))
#define current_fsgid() (current_cred_xxx(fsgid))
#define current_cap() (current_cred_xxx(cap_effective))
#define current_user() (current_cred_xxx(user))
+#define current_user_ns() (current_cred_xxx(user)->user_ns)
#define current_security() (current_cred_xxx(security))
#define current_uid_gid(_uid, _gid) \
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