linux/security/apparmor/procattr.c
John Johansen aa9a39ad8f apparmor: convert change_profile to use fqname later to give better control
Moving the use of fqname to later allows learning profiles to be based
on the fqname request instead of just the hname. It also allows cleaning
up some of the name parsing and lookup by allowing the use of
the fqlookupn_profile() lib fn.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:49 -08:00

152 lines
4.2 KiB
C

/*
* AppArmor security module
*
* This file contains AppArmor /proc/<pid>/attr/ interface functions
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*
* 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, version 2 of the
* License.
*/
#include "include/apparmor.h"
#include "include/context.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_profile *profile, char **string)
{
char *str;
int len = 0, mode_len = 0, ns_len = 0, name_len;
const char *mode_str = aa_profile_mode_names[profile->mode];
const char *ns_name = NULL;
struct aa_ns *ns = profile->ns;
struct aa_ns *current_ns = __aa_current_profile()->ns;
char *s;
if (!aa_ns_visible(current_ns, ns, true))
return -EACCES;
ns_name = aa_ns_name(current_ns, ns, true);
ns_len = strlen(ns_name);
/* if the visible ns_name is > 0 increase size for : :// seperator */
if (ns_len)
ns_len += 4;
/* unconfined profiles don't have a mode string appended */
if (!unconfined(profile))
mode_len = strlen(mode_str) + 3; /* + 3 for _() */
name_len = strlen(profile->base.hname);
len = mode_len + ns_len + name_len + 1; /* + 1 for \n */
s = str = kmalloc(len + 1, GFP_KERNEL); /* + 1 \0 */
if (!str)
return -ENOMEM;
if (ns_len) {
/* skip over prefix current_ns->base.hname and separating // */
sprintf(s, ":%s://", ns_name);
s += ns_len;
}
if (unconfined(profile))
/* mode string not being appended */
sprintf(s, "%s\n", profile->base.hname);
else
sprintf(s, "%s (%s)\n", profile->base.hname, mode_str);
*string = str;
/* NOTE: len does not include \0 of string, not saved as part of file */
return len;
}
/**
* 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
* @test: true if this is a test of change_hat permissions
*
* Returns: %0 or error code if change_hat fails
*/
int aa_setprocattr_changehat(char *args, size_t size, int test)
{
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, test);
}