linux-imx

/* Common capabilities, needed by capability.o.

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 */

​

#include <linux/capability.h>

#include <linux/audit.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/lsm_hooks.h>

#include <linux/file.h>

#include <linux/mm.h>

#include <linux/mman.h>

#include <linux/pagemap.h>

#include <linux/swap.h>

#include <linux/skbuff.h>

#include <linux/netlink.h>

#include <linux/ptrace.h>

#include <linux/xattr.h>

#include <linux/hugetlb.h>

#include <linux/mount.h>

#include <linux/sched.h>

#include <linux/prctl.h>

#include <linux/securebits.h>

#include <linux/user_namespace.h>

#include <linux/binfmts.h>

#include <linux/personality.h>

​

/*

 * If a non-root user executes a setuid-root binary in

 * !secure(SECURE_NOROOT) mode, then we raise capabilities.

 * However if fE is also set, then the intent is for only

 * the file capabilities to be applied, and the setuid-root

 * bit is left on either to change the uid (plausible) or

 * to get full privilege on a kernel without file capabilities

 * support.  So in that case we do not raise capabilities.

 *

 * Warn if that happens, once per boot.

 */

static void warn_setuid_and_fcaps_mixed(const char *fname)

{

    static int warned;

    if (!warned) {

        printk(KERN_INFO "warning: `%s' has both setuid-root and"

            " effective capabilities. Therefore not raising all"

            " capabilities.\n", fname);

        warned = 1;

    }

}

​

/**

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

 * @cred: The credentials to use

 * @ns:  The user namespace in which we need the capability

 * @cap: The capability to check for

 * @opts: Bitmask of options defined in include/linux/security.h

 *

 * Determine whether the nominated task has the specified capability amongst

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

 *

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

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

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

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

 */

int cap_capable(const struct cred *cred, struct user_namespace *targ_ns,

        int cap, unsigned int opts)

{

    struct user_namespace *ns = targ_ns;

​

    /* See if cred has the capability in the target user namespace

     * by examining the target user namespace and all of the target

     * user namespace's parents.

     */

    for (;;) {

        /* Do we have the necessary capabilities? */

        if (ns == cred->user_ns)

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

​

        /*

         * If we're already at a lower level than we're looking for,

         * we're done searching.

         */

        if (ns->level <= cred->user_ns->level)

            return -EPERM;

​

        /* 

         * The owner of the user namespace in the parent of the