[linux-2.6-block.git] / include / linux / cred.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Credentials management - see Documentation/security/credentials.rst
 *
 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#ifndef _LINUX_CRED_H
#define _LINUX_CRED_H

#include <linux/capability.h>
#include <linux/init.h>
#include <linux/key.h>
#include <linux/atomic.h>
#include <linux/uidgid.h>
#include <linux/sched.h>
#include <linux/sched/user.h>

struct cred;
struct inode;

/*
 * COW Supplementary groups list
 */
struct group_info {
	atomic_t	usage;
	int		ngroups;
	kgid_t		gid[0];
} __randomize_layout;

/**
 * get_group_info - Get a reference to a group info structure
 * @group_info: The group info to reference
 *
 * This gets a reference to a set of supplementary groups.
 *
 * If the caller is accessing a task's credentials, they must hold the RCU read
 * lock when reading.
 */
static inline struct group_info *get_group_info(struct group_info *gi)
{
	atomic_inc(&gi->usage);
	return gi;
}

/**
 * put_group_info - Release a reference to a group info structure
 * @group_info: The group info to release
 */
#define put_group_info(group_info)			\
do {							\
	if (atomic_dec_and_test(&(group_info)->usage))	\
		groups_free(group_info);		\
} while (0)

extern struct group_info init_groups;
#ifdef CONFIG_MULTIUSER
extern struct group_info *groups_alloc(int);
extern void groups_free(struct group_info *);

extern int in_group_p(kgid_t);
extern int in_egroup_p(kgid_t);
extern int groups_search(const struct group_info *, kgid_t);

extern int set_current_groups(struct group_info *);
extern void set_groups(struct cred *, struct group_info *);
extern bool may_setgroups(void);
extern void groups_sort(struct group_info *);
#else
static inline void groups_free(struct group_info *group_info)
{
}

static inline int in_group_p(kgid_t grp)
{
        return 1;
}
static inline int in_egroup_p(kgid_t grp)
{
        return 1;
}
static inline int groups_search(const struct group_info *group_info, kgid_t grp)
{
	return 1;
}
#endif

/*
 * The security context of a task
 *
 * The parts of the context break down into two categories:
 *
 *  (1) The objective context of a task.  These parts are used when some other
 *	task is attempting to affect this one.
 *
 *  (2) The subjective context.  These details are used when the task is acting
 *	upon another object, be that a file, a task, a key or whatever.
 *
 * Note that some members of this structure belong to both categories - the
 * LSM security pointer for instance.
 *
 * A task has two security pointers.  task->real_cred points to the objective
 * context that defines that task's actual details.  The objective part of this
 * context is used whenever that task is acted upon.
 *
 * task->cred points to the subjective context that defines the details of how
 * that task is going to act upon another object.  This may be overridden
 * temporarily to point to another security context, but normally points to the
 * same context as task->real_cred.
 */
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
	kuid_t		uid;		/* real UID of the task */
	kgid_t		gid;		/* real GID of the task */
	kuid_t		suid;		/* saved UID of the task */
	kgid_t		sgid;		/* saved GID of the task */
	kuid_t		euid;		/* effective UID of the task */
	kgid_t		egid;		/* effective GID of the task */
	kuid_t		fsuid;		/* UID for VFS ops */
	kgid_t		fsgid;		/* GID for VFS ops */
	unsigned	securebits;	/* SUID-less security management */
	kernel_cap_t	cap_inheritable; /* caps our children can inherit */
	kernel_cap_t	cap_permitted;	/* caps we're permitted */
	kernel_cap_t	cap_effective;	/* caps we can actually use */
	kernel_cap_t	cap_bset;	/* capability bounding set */
	kernel_cap_t	cap_ambient;	/* Ambient capability set */
#ifdef CONFIG_KEYS
	unsigned char	jit_keyring;	/* default keyring to attach requested
					 * keys to */
	struct key	*session_keyring; /* keyring inherited over fork */
	struct key	*process_keyring; /* keyring private to this process */
	struct key	*thread_keyring; /* keyring private to this thread */
	struct key	*request_key_auth; /* assumed request_key authority */
#endif
#ifdef CONFIG_SECURITY
	void		*security;	/* subjective LSM security */
#endif
	struct user_struct *user;	/* real user ID subscription */
	struct user_namespace *user_ns; /* user_ns the caps and keyrings are relative to. */
	struct group_info *group_info;	/* supplementary groups for euid/fsgid */
	/* RCU deletion */
	union {
		int non_rcu;			/* Can we skip RCU deletion? */
		struct rcu_head	rcu;		/* RCU deletion hook */
	};
} __randomize_layout;

extern void __put_cred(struct cred *);
extern void exit_creds(struct task_struct *);
extern int copy_creds(struct task_struct *, unsigned long);
extern const struct cred *get_task_cred(struct task_struct *);
extern struct cred *cred_alloc_blank(void);
extern struct cred *prepare_creds(void);
extern struct cred *prepare_exec_creds(void);
extern int commit_creds(struct cred *);
extern void abort_creds(struct cred *);
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 int cred_fscmp(const struct cred *, const struct cred *);
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

static inline bool cap_ambient_invariant_ok(const struct cred *cred)
{
	return cap_issubset(cred->cap_ambient,
			    cap_intersect(cred->cap_permitted,
					  cred->cap_inheritable));
}

/**
 * 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 new credentials.  The caller must
 * release the reference.
 */
static inline struct cred *get_new_cred(struct cred *cred)
{
	atomic_inc(&cred->usage);
	return cred;
}

/**
 * get_cred - Get a reference on a set of credentials
 * @cred: The credentials to reference
 *
 * Get a reference on the specified set of credentials.  The caller must
 * release the reference.  If %NULL is passed, it is returned with no action.
 *
 * 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)
{
	struct cred *nonconst_cred = (struct cred *) cred;
	if (!cred)
		return cred;
	validate_creds(cred);
	nonconst_cred->non_rcu = 0;
	return get_new_cred(nonconst_cred);
}

static inline const struct cred *get_cred_rcu(const struct cred *cred)
{
	struct cred *nonconst_cred = (struct cred *) cred;
	if (!cred)
		return NULL;
	if (!atomic_inc_not_zero(&nonconst_cred->usage))
		return NULL;
	validate_creds(cred);
	nonconst_cred->non_rcu = 0;
	return cred;
}

/**
 * put_cred - Release a reference to a set of credentials
 * @cred: The credentials to release
 *
 * Release a reference to a set of credentials, deleting them when the last ref
 * is released.  If %NULL is passed, nothing is done.
 *
 * 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;

	if (cred) {
		validate_creds(cred);
		if (atomic_dec_and_test(&(cred)->usage))
			__put_cred(cred);
	}
}

/**
 * current_cred - Access the current task's subjective credentials
 *
 * Access the subjective credentials of the current task.  RCU-safe,
 * since nobody else can modify it.
 */
#define current_cred() \
	rcu_dereference_protected(current->cred, 1)

/**
 * current_real_cred - Access the current task's objective credentials
 *
 * Access the objective credentials of the current task.  RCU-safe,
 * since nobody else can modify it.
 */
#define current_real_cred() \
	rcu_dereference_protected(current->real_cred, 1)

/**
 * __task_cred - Access a task's objective credentials
 * @task: The task to query
 *
 * Access the objective credentials of a task.  The caller must hold the RCU
 * readlock.
 *
 * The result of this function should not be passed directly to get_cred();
 * rather get_task_cred() should be used instead.
 */
#define __task_cred(task)	\
	rcu_dereference((task)->real_cred)

/**
 * get_current_cred - Get the current task's subjective credentials
 *
 * 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()))

/**
 * get_current_user - Get the current task's user_struct
 *
 * Get the user record of the current task, pinning it so that it can't go
 * away.
 */
#define get_current_user()				\
({							\
	struct user_struct *__u;			\
	const struct cred *__cred;			\
	__cred = current_cred();			\
	__u = get_uid(__cred->user);			\
	__u;						\
})

/**
 * get_current_groups - Get the current task's supplementary group list
 *
 * Get the supplementary group list of the current task, pinning it so that it
 * can't go away.
 */
#define get_current_groups()				\
({							\
	struct group_info *__groups;			\
	const struct cred *__cred;			\
	__cred = current_cred();			\
	__groups = get_group_info(__cred->group_info);	\
	__groups;					\
})

#define task_cred_xxx(task, xxx)			\
({							\
	__typeof__(((struct cred *)NULL)->xxx) ___val;	\
	rcu_read_lock();				\
	___val = __task_cred((task))->xxx;		\
	rcu_read_unlock();				\
	___val;						\
})

#define task_uid(task)		(task_cred_xxx((task), uid))
#define task_euid(task)		(task_cred_xxx((task), euid))

#define current_cred_xxx(xxx)			\
({						\
	current_cred()->xxx;			\
})

#define current_uid()		(current_cred_xxx(uid))
#define current_gid()		(current_cred_xxx(gid))
#define current_euid()		(current_cred_xxx(euid))
#define current_egid()		(current_cred_xxx(egid))
#define current_suid()		(current_cred_xxx(suid))
#define current_sgid()		(current_cred_xxx(sgid))
#define current_fsuid() 	(current_cred_xxx(fsuid))
#define current_fsgid() 	(current_cred_xxx(fsgid))
#define current_cap()		(current_cred_xxx(cap_effective))
#define current_user()		(current_cred_xxx(user))

extern struct user_namespace init_user_ns;
#ifdef CONFIG_USER_NS
#define current_user_ns()	(current_cred_xxx(user_ns))
#else
static inline struct user_namespace *current_user_ns(void)
{
	return &init_user_ns;
}
#endif


#define current_uid_gid(_uid, _gid)		\
do {						\
	const struct cred *__cred;		\
	__cred = current_cred();		\
	*(_uid) = __cred->uid;			\
	*(_gid) = __cred->gid;			\
} while(0)

#define current_euid_egid(_euid, _egid)		\
do {						\
	const struct cred *__cred;		\
	__cred = current_cred();		\
	*(_euid) = __cred->euid;		\
	*(_egid) = __cred->egid;		\
} while(0)

#define current_fsuid_fsgid(_fsuid, _fsgid)	\
do {						\
	const struct cred *__cred;		\
	__cred = current_cred();		\
	*(_fsuid) = __cred->fsuid;		\
	*(_fsgid) = __cred->fsgid;		\
} while(0)

#endif /* _LINUX_CRED_H */
Commit	Line	Data
b4d0d230	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
af777cd1	2	/* Credentials management - see Documentation/security/credentials.rst
9e2b2dc4 DH	3	*
	4	* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
9e2b2dc4 DH	6	*/
	7
	8	#ifndef _LINUX_CRED_H
	9	#define _LINUX_CRED_H
	10
b6dff3ec	11	#include <linux/capability.h>
b2e1feaf	12	#include <linux/init.h>
b6dff3ec	13	#include <linux/key.h>
60063497	14	#include <linux/atomic.h>
ae2975bc	15	#include <linux/uidgid.h>
5b825c3a	16	#include <linux/sched.h>
8703e8a4	17	#include <linux/sched/user.h>
b6dff3ec	18
b6dff3ec	19	struct cred;
3a3b7ce9	20	struct inode;
b6dff3ec DH	21
	22	/*
	23	* COW Supplementary groups list
	24	*/
b6dff3ec DH	25	struct group_info {
	26	atomic_t usage;
	27	int ngroups;
81243eac	28	kgid_t gid[0];
3859a271	29	} __randomize_layout;
b6dff3ec DH	30
	31	/**
	32	* get_group_info - Get a reference to a group info structure
	33	* @group_info: The group info to reference
	34	*
86a264ab DH	35	* This gets a reference to a set of supplementary groups.
	36	*
	37	* If the caller is accessing a task's credentials, they must hold the RCU read
	38	* lock when reading.
b6dff3ec	39	*/
86a264ab DH	40	static inline struct group_info get_group_info(struct group_info gi)
	41	{
	42	atomic_inc(&gi->usage);
	43	return gi;
	44	}
b6dff3ec DH	45
	46	/**
	47	* put_group_info - Release a reference to a group info structure
	48	* @group_info: The group info to release
	49	*/
	50	#define put_group_info(group_info) \
	51	do { \
	52	if (atomic_dec_and_test(&(group_info)->usage)) \
	53	groups_free(group_info); \
	54	} while (0)
	55
18b6e041	56	extern struct group_info init_groups;
2813893f IM	57	#ifdef CONFIG_MULTIUSER
2813893f IM	58	extern struct group_info *groups_alloc(int);
b6dff3ec	59	extern void groups_free(struct group_info *);
2813893f IM	60
	61	extern int in_group_p(kgid_t);
	62	extern int in_egroup_p(kgid_t);
4b09791b OM	63	extern int groups_search(const struct group_info *, kgid_t);
	64
	65	extern int set_current_groups(struct group_info *);
	66	extern void set_groups(struct cred , struct group_info );
	67	extern bool may_setgroups(void);
	68	extern void groups_sort(struct group_info *);
2813893f IM	69	#else
	70	static inline void groups_free(struct group_info *group_info)
	71	{
	72	}
	73
	74	static inline int in_group_p(kgid_t grp)
	75	{
	76	return 1;
	77	}
	78	static inline int in_egroup_p(kgid_t grp)
	79	{
	80	return 1;
	81	}
4b09791b OM	82	static inline int groups_search(const struct group_info *group_info, kgid_t grp)
	83	{
	84	return 1;
	85	}
2813893f	86	#endif
b6dff3ec	87
b6dff3ec DH	88	/*
	89	* The security context of a task
	90	*
	91	* The parts of the context break down into two categories:
	92	*
	93	* (1) The objective context of a task. These parts are used when some other
	94	* task is attempting to affect this one.
	95	*
	96	* (2) The subjective context. These details are used when the task is acting
	97	* upon another object, be that a file, a task, a key or whatever.
	98	*
	99	* Note that some members of this structure belong to both categories - the
	100	* LSM security pointer for instance.
	101	*
	102	* A task has two security pointers. task->real_cred points to the objective
	103	* context that defines that task's actual details. The objective part of this
	104	* context is used whenever that task is acted upon.
	105	*
	106	* task->cred points to the subjective context that defines the details of how
	107	* that task is going to act upon another object. This may be overridden
	108	* temporarily to point to another security context, but normally points to the
	109	* same context as task->real_cred.
	110	*/
	111	struct cred {
	112	atomic_t usage;
e0e81739 DH	113	#ifdef CONFIG_DEBUG_CREDENTIALS
	114	atomic_t subscribers; /* number of processes subscribed */
	115	void *put_addr;
	116	unsigned magic;
	117	#define CRED_MAGIC 0x43736564
	118	#define CRED_MAGIC_DEAD 0x44656144
	119	#endif
078de5f7 EB	120	kuid_t uid; /* real UID of the task */
	121	kgid_t gid; /* real GID of the task */
	122	kuid_t suid; /* saved UID of the task */
	123	kgid_t sgid; /* saved GID of the task */
	124	kuid_t euid; /* effective UID of the task */
	125	kgid_t egid; /* effective GID of the task */
	126	kuid_t fsuid; /* UID for VFS ops */
	127	kgid_t fsgid; /* GID for VFS ops */
b6dff3ec DH	128	unsigned securebits; /* SUID-less security management */
	129	kernel_cap_t cap_inheritable; /* caps our children can inherit */
	130	kernel_cap_t cap_permitted; /* caps we're permitted */
	131	kernel_cap_t cap_effective; /* caps we can actually use */
	132	kernel_cap_t cap_bset; /* capability bounding set */
58319057	133	kernel_cap_t cap_ambient; /* Ambient capability set */
b6dff3ec DH	134	#ifdef CONFIG_KEYS
	135	unsigned char jit_keyring; /* default keyring to attach requested
	136	* keys to */
5c7e372c	137	struct key session_keyring; / keyring inherited over fork */
3a50597d	138	struct key process_keyring; / keyring private to this process */
b6dff3ec DH	139	struct key thread_keyring; / keyring private to this thread */
	140	struct key request_key_auth; / assumed request_key authority */
	141	#endif
	142	#ifdef CONFIG_SECURITY
	143	void security; / subjective LSM security */
	144	#endif
	145	struct user_struct user; / real user ID subscription */
0093ccb6	146	struct user_namespace user_ns; / user_ns the caps and keyrings are relative to. */
b6dff3ec	147	struct group_info group_info; / supplementary groups for euid/fsgid */
d7852fbd LT	148	/* RCU deletion */
	149	union {
	150	int non_rcu; /* Can we skip RCU deletion? */
	151	struct rcu_head rcu; /* RCU deletion hook */
	152	};
3859a271	153	} __randomize_layout;
b6dff3ec	154
f1752eec	155	extern void __put_cred(struct cred *);
e0e81739	156	extern void exit_creds(struct task_struct *);
f1752eec	157	extern int copy_creds(struct task_struct *, unsigned long);
de09a977	158	extern const struct cred get_task_cred(struct task_struct );
ee18d64c	159	extern struct cred *cred_alloc_blank(void);
d84f4f99	160	extern struct cred *prepare_creds(void);
a6f76f23	161	extern struct cred *prepare_exec_creds(void);
d84f4f99 DH	162	extern int commit_creds(struct cred *);
d84f4f99 DH	163	extern void abort_creds(struct cred *);
3b11a1de DH	164	extern const struct cred override_creds(const struct cred );
3b11a1de DH	165	extern void revert_creds(const struct cred *);
3a3b7ce9 DH	166	extern struct cred prepare_kernel_cred(struct task_struct );
	167	extern int change_create_files_as(struct cred , struct inode );
	168	extern int set_security_override(struct cred *, u32);
	169	extern int set_security_override_from_ctx(struct cred , const char );
	170	extern int set_create_files_as(struct cred , struct inode );
d89b22d4	171	extern int cred_fscmp(const struct cred , const struct cred );
d84f4f99 DH	172	extern void __init cred_init(void);
d84f4f99 DH	173
e0e81739 DH	174	/*
	175	* check for validity of credentials
	176	*/
	177	#ifdef CONFIG_DEBUG_CREDENTIALS
	178	extern void __invalid_creds(const struct cred , const char , unsigned);
	179	extern void __validate_process_creds(struct task_struct *,
	180	const char *, unsigned);
	181
74908a00	182	extern bool creds_are_invalid(const struct cred *cred);
e0e81739 DH	183
	184	static inline void __validate_creds(const struct cred *cred,
	185	const char *file, unsigned line)
	186	{
	187	if (unlikely(creds_are_invalid(cred)))
	188	__invalid_creds(cred, file, line);
	189	}
	190
	191	#define validate_creds(cred) \
	192	do { \
	193	__validate_creds((cred), __FILE__, __LINE__); \
	194	} while(0)
	195
	196	#define validate_process_creds() \
	197	do { \
	198	__validate_process_creds(current, __FILE__, __LINE__); \
	199	} while(0)
	200
	201	extern void validate_creds_for_do_exit(struct task_struct *);
	202	#else
	203	static inline void validate_creds(const struct cred *cred)
	204	{
	205	}
	206	static inline void validate_creds_for_do_exit(struct task_struct *tsk)
	207	{
	208	}
	209	static inline void validate_process_creds(void)
	210	{
	211	}
	212	#endif
	213
58319057 AL	214	static inline bool cap_ambient_invariant_ok(const struct cred *cred)
	215	{
	216	return cap_issubset(cred->cap_ambient,
	217	cap_intersect(cred->cap_permitted,
	218	cred->cap_inheritable));
	219	}
	220
d84f4f99 DH	221	/**
	222	* get_new_cred - Get a reference on a new set of credentials
	223	* @cred: The new credentials to reference
	224	*
	225	* Get a reference on the specified set of new credentials. The caller must
	226	* release the reference.
	227	*/
	228	static inline struct cred get_new_cred(struct cred cred)
	229	{
	230	atomic_inc(&cred->usage);
	231	return cred;
	232	}
f1752eec DH	233
	234	/**
	235	* get_cred - Get a reference on a set of credentials
	236	* @cred: The credentials to reference
	237	*
	238	* Get a reference on the specified set of credentials. The caller must
f06bc033	239	* release the reference. If %NULL is passed, it is returned with no action.
98870ab0 DH	240	*
	241	* This is used to deal with a committed set of credentials. Although the
	242	* pointer is const, this will temporarily discard the const and increment the
	243	* usage count. The purpose of this is to attempt to catch at compile time the
	244	* accidental alteration of a set of credentials that should be considered
	245	* immutable.
f1752eec	246	*/
d84f4f99	247	static inline const struct cred get_cred(const struct cred cred)
f1752eec	248	{
1c388ad0	249	struct cred nonconst_cred = (struct cred ) cred;
f06bc033 N	250	if (!cred)
f06bc033 N	251	return cred;
e0e81739	252	validate_creds(cred);
d7852fbd	253	nonconst_cred->non_rcu = 0;
1c388ad0	254	return get_new_cred(nonconst_cred);
f1752eec DH	255	}
f1752eec DH	256
97d0fb23 N	257	static inline const struct cred get_cred_rcu(const struct cred cred)
	258	{
	259	struct cred nonconst_cred = (struct cred ) cred;
	260	if (!cred)
	261	return NULL;
	262	if (!atomic_inc_not_zero(&nonconst_cred->usage))
	263	return NULL;
	264	validate_creds(cred);
d7852fbd	265	nonconst_cred->non_rcu = 0;
97d0fb23 N	266	return cred;
	267	}
	268
f1752eec DH	269	/**
	270	* put_cred - Release a reference to a set of credentials
	271	* @cred: The credentials to release
	272	*
	273	* Release a reference to a set of credentials, deleting them when the last ref
f06bc033	274	* is released. If %NULL is passed, nothing is done.
98870ab0 DH	275	*
	276	* This takes a const pointer to a set of credentials because the credentials
	277	* on task_struct are attached by const pointers to prevent accidental
	278	* alteration of otherwise immutable credential sets.
f1752eec	279	*/
c69e8d9c	280	static inline void put_cred(const struct cred *_cred)
f1752eec	281	{
c69e8d9c	282	struct cred cred = (struct cred ) _cred;
d84f4f99	283
f06bc033 N	284	if (cred) {
	285	validate_creds(cred);
	286	if (atomic_dec_and_test(&(cred)->usage))
	287	__put_cred(cred);
	288	}
f1752eec DH	289	}
f1752eec DH	290
86a264ab	291	/**
3b11a1de	292	* current_cred - Access the current task's subjective credentials
86a264ab	293	*
32955148 AV	294	* Access the subjective credentials of the current task. RCU-safe,
32955148 AV	295	* since nobody else can modify it.
86a264ab DH	296	*/
86a264ab DH	297	#define current_cred() \
27e4e436	298	rcu_dereference_protected(current->cred, 1)
86a264ab	299
ae4b884f JL	300	/**
	301	* current_real_cred - Access the current task's objective credentials
	302	*
	303	* Access the objective credentials of the current task. RCU-safe,
	304	* since nobody else can modify it.
	305	*/
	306	#define current_real_cred() \
	307	rcu_dereference_protected(current->real_cred, 1)
	308
86a264ab	309	/**
3b11a1de	310	* __task_cred - Access a task's objective credentials
86a264ab DH	311	* @task: The task to query
86a264ab DH	312	*
3b11a1de	313	* Access the objective credentials of a task. The caller must hold the RCU
43e13cc1	314	* readlock.
86a264ab	315	*
8f92054e DH	316	* The result of this function should not be passed directly to get_cred();
8f92054e DH	317	* rather get_task_cred() should be used instead.
86a264ab	318	*/
43e13cc1 ON	319	#define __task_cred(task) \
43e13cc1 ON	320	rcu_dereference((task)->real_cred)
86a264ab	321
86a264ab	322	/**
3b11a1de	323	* get_current_cred - Get the current task's subjective credentials
86a264ab	324	*
3b11a1de DH	325	* Get the subjective credentials of the current task, pinning them so that
	326	* they can't go away. Accessing the current task's credentials directly is
	327	* not permitted.
86a264ab DH	328	*/
	329	#define get_current_cred() \
	330	(get_cred(current_cred()))
	331
	332	/**
	333	* get_current_user - Get the current task's user_struct
	334	*
	335	* Get the user record of the current task, pinning it so that it can't go
	336	* away.
	337	*/
	338	#define get_current_user() \
	339	({ \
	340	struct user_struct *__u; \
638a8439	341	const struct cred *__cred; \
32955148	342	__cred = current_cred(); \
86a264ab DH	343	__u = get_uid(__cred->user); \
	344	__u; \
	345	})
	346
	347	/**
	348	* get_current_groups - Get the current task's supplementary group list
	349	*
	350	* Get the supplementary group list of the current task, pinning it so that it
	351	* can't go away.
	352	*/
	353	#define get_current_groups() \
	354	({ \
	355	struct group_info *__groups; \
638a8439	356	const struct cred *__cred; \
32955148	357	__cred = current_cred(); \
86a264ab DH	358	__groups = get_group_info(__cred->group_info); \
	359	__groups; \
	360	})
	361
d84f4f99 DH	362	#define task_cred_xxx(task, xxx) \
	363	({ \
	364	__typeof__(((struct cred *)NULL)->xxx) ___val; \
	365	rcu_read_lock(); \
	366	___val = __task_cred((task))->xxx; \
	367	rcu_read_unlock(); \
	368	___val; \
86a264ab DH	369	})
	370
	371	#define task_uid(task) (task_cred_xxx((task), uid))
	372	#define task_euid(task) (task_cred_xxx((task), euid))
	373
	374	#define current_cred_xxx(xxx) \
	375	({ \
32955148	376	current_cred()->xxx; \
86a264ab DH	377	})
	378
	379	#define current_uid() (current_cred_xxx(uid))
	380	#define current_gid() (current_cred_xxx(gid))
	381	#define current_euid() (current_cred_xxx(euid))
	382	#define current_egid() (current_cred_xxx(egid))
	383	#define current_suid() (current_cred_xxx(suid))
	384	#define current_sgid() (current_cred_xxx(sgid))
	385	#define current_fsuid() (current_cred_xxx(fsuid))
	386	#define current_fsgid() (current_cred_xxx(fsgid))
	387	#define current_cap() (current_cred_xxx(cap_effective))
	388	#define current_user() (current_cred_xxx(user))
86a264ab	389
7e6bd8fa	390	extern struct user_namespace init_user_ns;
47a150ed	391	#ifdef CONFIG_USER_NS
f1c84dae	392	#define current_user_ns() (current_cred_xxx(user_ns))
47a150ed	393	#else
0335695d AB	394	static inline struct user_namespace *current_user_ns(void)
	395	{
	396	return &init_user_ns;
	397	}
47a150ed SH	398	#endif
47a150ed SH	399
3486740a	400
86a264ab DH	401	#define current_uid_gid(_uid, _gid) \
	402	do { \
	403	const struct cred *__cred; \
	404	__cred = current_cred(); \
	405	*(_uid) = __cred->uid; \
	406	*(_gid) = __cred->gid; \
	407	} while(0)
	408
	409	#define current_euid_egid(_euid, _egid) \
	410	do { \
	411	const struct cred *__cred; \
	412	__cred = current_cred(); \
	413	*(_euid) = __cred->euid; \
	414	*(_egid) = __cred->egid; \
	415	} while(0)
	416
	417	#define current_fsuid_fsgid(_fsuid, _fsgid) \
	418	do { \
	419	const struct cred *__cred; \
	420	__cred = current_cred(); \
	421	*(_fsuid) = __cred->fsuid; \
	422	*(_fsgid) = __cred->fsgid; \
	423	} while(0)
	424
9e2b2dc4	425	#endif /* _LINUX_CRED_H */