linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Supplementary group IDs

 */

#include <linux/cred.h>

#include <linux/export.h>

#include <linux/slab.h>

#include <linux/security.h>

#include <linux/sort.h>

#include <linux/syscalls.h>

#include <linux/user_namespace.h>

#include <linux/vmalloc.h>

#include <linux/uaccess.h>

​

struct group_info *groups_alloc(int gidsetsize)

{

    struct group_info *gi;

    unsigned int len;

​

    len = sizeof(struct group_info) + sizeof(kgid_t) * gidsetsize;

    gi = kmalloc(len, GFP_KERNEL_ACCOUNT|__GFP_NOWARN|__GFP_NORETRY);

    if (!gi)

        gi = __vmalloc(len, GFP_KERNEL_ACCOUNT, PAGE_KERNEL);

    if (!gi)

        return NULL;

​

    atomic_set(&gi->usage, 1);

    gi->ngroups = gidsetsize;

    return gi;

}

​

EXPORT_SYMBOL(groups_alloc);

​

void groups_free(struct group_info *group_info)

{

    kvfree(group_info);

}

​

EXPORT_SYMBOL(groups_free);

​

/* export the group_info to a user-space array */

static int groups_to_user(gid_t __user *grouplist,

              const struct group_info *group_info)

{

    struct user_namespace *user_ns = current_user_ns();

    int i;

    unsigned int count = group_info->ngroups;

​

    for (i = 0; i < count; i++) {

        gid_t gid;

        gid = from_kgid_munged(user_ns, group_info->gid[i]);

        if (put_user(gid, grouplist+i))

            return -EFAULT;

    }

    return 0;

}

​

/* fill a group_info from a user-space array - it must be allocated already */

static int groups_from_user(struct group_info *group_info,

    gid_t __user *grouplist)

{

    struct user_namespace *user_ns = current_user_ns();

    int i;