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Commit 29881c45 authored by James Morris's avatar James Morris
Browse files

Revert "CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2]" 

This reverts commit 14eaddc9.

David has a better version to come.
parent 76f7ba35

include/linux/capability.h

+2 −15
Original line number Diff line number Diff line
@@ -529,21 +529,8 @@ extern const kernel_cap_t __cap_init_eff_set; 
 *

 * Note that this does not set PF_SUPERPRIV on the task.

 */

#define has_capability(t, cap) (security_task_capable((t), (cap)) == 0)



/**

 * has_capability_noaudit - Determine if a task has a superior capability available (unaudited)

 * @t: The task in question

 * @cap: The capability to be tested for

 *

 * Return true if the specified task has the given superior capability

 * currently in effect, false if not, but don't write an audit message for the

 * check.

 *

 * Note that this does not set PF_SUPERPRIV on the task.

 */

#define has_capability_noaudit(t, cap) \

	(security_task_capable_noaudit((t), (cap)) == 0)

#define has_capability(t, cap) (security_capable((t), (cap)) == 0)

#define has_capability_noaudit(t, cap) (security_capable_noaudit((t), (cap)) == 0)



extern int capable(int cap);

include/linux/security.h

+9 −40
Original line number Diff line number Diff line
@@ -48,9 +48,7 @@ struct audit_krule; 
 * These functions are in security/capability.c and are used

 * as the default capabilities functions

 */

extern int cap_capable(int cap, int audit);

extern int cap_task_capable(struct task_struct *tsk, const struct cred *cred,

			    int cap, int audit);

extern int cap_capable(struct task_struct *tsk, int cap, int audit);

extern int cap_settime(struct timespec *ts, struct timezone *tz);

extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode);

extern int cap_ptrace_traceme(struct task_struct *parent);
@@ -1197,18 +1195,9 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) 
 *	@permitted contains the permitted capability set.

 *	Return 0 and update @new if permission is granted.

 * @capable:

 *	Check whether the current process has the @cap capability in its

 *      subjective/effective credentials.

 *	@cap contains the capability <include/linux/capability.h>.

 *	@audit: Whether to write an audit message or not

 *	Return 0 if the capability is granted for @tsk.

 * @task_capable:

 *	Check whether the @tsk process has the @cap capability in its

 *      objective/real credentials.

 *	Check whether the @tsk process has the @cap capability.

 *	@tsk contains the task_struct for the process.

 *	@cred contains the credentials to use.

 *	@cap contains the capability <include/linux/capability.h>.

 *	@audit: Whether to write an audit message or not

 *	Return 0 if the capability is granted for @tsk.

 * @acct:

 *	Check permission before enabling or disabling process accounting.  If
@@ -1301,9 +1290,7 @@ struct security_operations { 
		       const kernel_cap_t *effective,

		       const kernel_cap_t *inheritable,

		       const kernel_cap_t *permitted);

	int (*capable) (int cap, int audit);

	int (*task_capable) (struct task_struct *tsk, const struct cred *cred,

			     int cap, int audit);

	int (*capable) (struct task_struct *tsk, int cap, int audit);

	int (*acct) (struct file *file);

	int (*sysctl) (struct ctl_table *table, int op);

	int (*quotactl) (int cmds, int type, int id, struct super_block *sb);
@@ -1569,9 +1556,8 @@ int security_capset(struct cred *new, const struct cred *old, 
		    const kernel_cap_t *effective,

		    const kernel_cap_t *inheritable,

		    const kernel_cap_t *permitted);

int security_capable(int cap);

int security_task_capable(struct task_struct *tsk, int cap);

int security_task_capable_noaudit(struct task_struct *tsk, int cap);

int security_capable(struct task_struct *tsk, int cap);

int security_capable_noaudit(struct task_struct *tsk, int cap);

int security_acct(struct file *file);

int security_sysctl(struct ctl_table *table, int op);

int security_quotactl(int cmds, int type, int id, struct super_block *sb);
@@ -1768,31 +1754,14 @@ static inline int security_capset(struct cred *new, 
	return cap_capset(new, old, effective, inheritable, permitted);

}



static inline int security_capable(int cap)

static inline int security_capable(struct task_struct *tsk, int cap)

{

	return cap_capable(cap, SECURITY_CAP_AUDIT);

	return cap_capable(tsk, cap, SECURITY_CAP_AUDIT);

}



static inline int security_task_capable(struct task_struct *tsk, int cap)

static inline int security_capable_noaudit(struct task_struct *tsk, int cap)

{

	int ret;



	rcu_read_lock();

	ret = cap_task_capable(tsk, __task_cred(tsk), cap, SECURITY_CAP_AUDIT);

	rcu_read_unlock();

	return ret;

}



static inline

int security_task_capable_noaudit(struct task_struct *tsk, int cap)

{

	int ret;



	rcu_read_lock();

	ret = cap_task_capable(tsk, __task_cred(tsk), cap,

			       SECURITY_CAP_NOAUDIT);

	rcu_read_unlock();

	return ret;

	return cap_capable(tsk, cap, SECURITY_CAP_NOAUDIT);

}



static inline int security_acct(struct file *file)

kernel/capability.c

+1 −1
Original line number Diff line number Diff line
@@ -308,7 +308,7 @@ int capable(int cap) 
		BUG();

	}



	if (security_capable(cap) == 0) {

	if (has_capability(current, cap)) {

		current->flags |= PF_SUPERPRIV;

		return 1;

	}

security/capability.c

+0 −1
Original line number Diff line number Diff line
@@ -826,7 +826,6 @@ void security_fixup_ops(struct security_operations *ops) 
	set_to_cap_if_null(ops, capset);

	set_to_cap_if_null(ops, acct);

	set_to_cap_if_null(ops, capable);

	set_to_cap_if_null(ops, task_capable);

	set_to_cap_if_null(ops, quotactl);

	set_to_cap_if_null(ops, quota_on);

	set_to_cap_if_null(ops, sysctl);

security/commoncap.c

+13 −29
Original line number Diff line number Diff line
@@ -43,44 +43,28 @@ int cap_netlink_recv(struct sk_buff *skb, int cap) 
EXPORT_SYMBOL(cap_netlink_recv);



/**

 * cap_capable - Determine whether current has a particular effective capability

 * cap_capable - Determine whether a task has a particular effective capability

 * @tsk: The task to query

 * @cap: The capability to check for

 * @audit: Whether to write an audit message or not

 *

 * Determine whether the nominated task has the specified capability amongst

 * its effective set, returning 0 if it does, -ve if it does not.  Note that

 * this uses current's subjective/effective credentials.

 * its effective set, returning 0 if it does, -ve if it does not.

 *

 * NOTE WELL: cap_capable() cannot be used like the kernel's capable()

 * function.  That is, it has the reverse semantics: cap_capable() returns 0

 * when a task has a capability, but the kernel's capable() returns 1 for this

 * case.

 */

int cap_capable(int cap, int audit)

int cap_capable(struct task_struct *tsk, int cap, int audit)

{

	return cap_raised(current_cap(), cap) ? 0 : -EPERM;

}

	__u32 cap_raised;



/**

 * cap_has_capability - Determine whether a task has a particular effective capability

 * @tsk: The task to query

 * @cred: The credentials to use

 * @cap: The capability to check for

 * @audit: Whether to write an audit message or not

 *

 * Determine whether the nominated task has the specified capability amongst

 * its effective set, returning 0 if it does, -ve if it does not.  Note that

 * this uses the task's objective/real credentials.

 *

 * NOTE WELL: cap_has_capability() cannot be used like the kernel's

 * has_capability() function.  That is, it has the reverse semantics:

 * cap_has_capability() returns 0 when a task has a capability, but the

 * kernel's has_capability() returns 1 for this case.

 */

int cap_task_capable(struct task_struct *tsk, const struct cred *cred, int cap,

		     int audit)

{

	return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;

	/* Derived from include/linux/sched.h:capable. */

	rcu_read_lock();

	cap_raised = cap_raised(__task_cred(tsk)->cap_effective, cap);

	rcu_read_unlock();

	return cap_raised ? 0 : -EPERM;

}



/**
@@ -176,7 +160,7 @@ static inline int cap_inh_is_capped(void) 
	/* they are so limited unless the current task has the CAP_SETPCAP

	 * capability

	 */

	if (cap_capable(CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0)

	if (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0)

		return 0;

#endif

	return 1;
@@ -885,7 +869,7 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, 
		     & (new->securebits ^ arg2))			/*[1]*/

		    || ((new->securebits & SECURE_ALL_LOCKS & ~arg2))	/*[2]*/

		    || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS))	/*[3]*/

		    || (cap_capable(CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/

		    || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/

			/*

			 * [1] no changing of bits that are locked

			 * [2] no unlocking of locks
@@ -966,7 +950,7 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages) 
{

	int cap_sys_admin = 0;



	if (cap_capable(CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0)

	if (cap_capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0)

		cap_sys_admin = 1;

	return __vm_enough_memory(mm, pages, cap_sys_admin);

}