linux/security/apparmor/procattr.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* AppArmor security module
*
* This file contains AppArmor /proc/<pid>/attr/ interface functions
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*/
#include "include/apparmor.h"
#include "include/cred.h"
#include "include/policy.h"
#include "include/policy_ns.h"
#include "include/domain.h"
#include "include/procattr.h"
/**
* aa_getprocattr - Return the profile information for @profile
* @profile: the profile to print profile info about (NOT NULL)
* @string: Returns - string containing the profile info (NOT NULL)
*
* Returns: length of @string on success else error on failure
*
* Requires: profile != NULL
*
* Creates a string containing the namespace_name://profile_name for
* @profile.
*
* Returns: size of string placed in @string else error code on failure
*/
int aa_getprocattr(struct aa_label *label, char **string)
{
struct aa_ns *ns = labels_ns(label);
struct aa_ns *current_ns = aa_get_current_ns();
int len;
if (!aa_ns_visible(current_ns, ns, true)) {
aa_put_ns(current_ns);
return -EACCES;
}
len = aa_label_snxprint(NULL, 0, current_ns, label,
FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
FLAG_HIDDEN_UNCONFINED);
AA_BUG(len < 0);
*string = kmalloc(len + 2, GFP_KERNEL);
if (!*string) {
aa_put_ns(current_ns);
return -ENOMEM;
}
len = aa_label_snxprint(*string, len + 2, current_ns, label,
FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
FLAG_HIDDEN_UNCONFINED);
if (len < 0) {
aa_put_ns(current_ns);
return len;
}
(*string)[len] = '\n';
(*string)[len + 1] = 0;
aa_put_ns(current_ns);
return len + 1;
}
/**
* split_token_from_name - separate a string of form <token>^<name>
* @op: operation being checked
* @args: string to parse (NOT NULL)
* @token: stores returned parsed token value (NOT NULL)
*
* Returns: start position of name after token else NULL on failure
*/
static char *split_token_from_name(const char *op, char *args, u64 *token)
{
char *name;
*token = simple_strtoull(args, &name, 16);
if ((name == args) || *name != '^') {
AA_ERROR("%s: Invalid input '%s'", op, args);
return ERR_PTR(-EINVAL);
}
name++; /* skip ^ */
if (!*name)
name = NULL;
return name;
}
/**
* aa_setprocattr_chagnehat - handle procattr interface to change_hat
* @args: args received from writing to /proc/<pid>/attr/current (NOT NULL)
* @size: size of the args
* @flags: set of flags governing behavior
*
* Returns: %0 or error code if change_hat fails
*/
int aa_setprocattr_changehat(char *args, size_t size, int flags)
{
char *hat;
u64 token;
const char *hats[16]; /* current hard limit on # of names */
int count = 0;
hat = split_token_from_name(OP_CHANGE_HAT, args, &token);
if (IS_ERR(hat))
return PTR_ERR(hat);
if (!hat && !token) {
AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
return -EINVAL;
}
if (hat) {
/* set up hat name vector, args guaranteed null terminated
* at args[size] by setprocattr.
*
* If there are multiple hat names in the buffer each is
* separated by a \0. Ie. userspace writes them pre tokenized
*/
char *end = args + size;
for (count = 0; (hat < end) && count < 16; ++count) {
char *next = hat + strlen(hat) + 1;
hats[count] = hat;
AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d hat '%s'\n"
, __func__, current->pid, token, count, hat);
hat = next;
}
} else
AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d Hat '%s'\n",
__func__, current->pid, token, count, "<NULL>");
return aa_change_hat(hats, count, token, flags);
}