summaryrefslogtreecommitdiff
path: root/security/apparmor/procattr.c
blob: c929bf4a3df1c0b005996cb04b620d9ff0f40854 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
// 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);
}