1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AppArmor security module
4 *
5 * This file contains AppArmor /proc/<pid>/attr/ interface functions
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
9 */
10
11 #include "include/apparmor.h"
12 #include "include/cred.h"
13 #include "include/policy.h"
14 #include "include/policy_ns.h"
15 #include "include/domain.h"
16 #include "include/procattr.h"
17
18
19 /**
20 * aa_getprocattr - Return the profile information for @profile
21 * @profile: the profile to print profile info about (NOT NULL)
22 * @string: Returns - string containing the profile info (NOT NULL)
23 *
24 * Returns: length of @string on success else error on failure
25 *
26 * Requires: profile != NULL
27 *
28 * Creates a string containing the namespace_name://profile_name for
29 * @profile.
30 *
31 * Returns: size of string placed in @string else error code on failure
32 */
33 int aa_getprocattr(struct aa_label *label, char **string)
34 {
35 struct aa_ns *ns = labels_ns(label);
36 struct aa_ns *current_ns = aa_get_current_ns();
37 int len;
38
39 if (!aa_ns_visible(current_ns, ns, true)) {
40 aa_put_ns(current_ns);
41 return -EACCES;
42 }
43
44 len = aa_label_snxprint(NULL, 0, current_ns, label,
45 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
46 FLAG_HIDDEN_UNCONFINED);
47 AA_BUG(len < 0);
48
49 *string = kmalloc(len + 2, GFP_KERNEL);
50 if (!*string) {
51 aa_put_ns(current_ns);
52 return -ENOMEM;
53 }
54
55 len = aa_label_snxprint(*string, len + 2, current_ns, label,
56 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
57 FLAG_HIDDEN_UNCONFINED);
58 if (len < 0) {
59 aa_put_ns(current_ns);
60 return len;
61 }
62
63 (*string)[len] = '\n';
64 (*string)[len + 1] = 0;
65
66 aa_put_ns(current_ns);
67 return len + 1;
68 }
69
70 /**
71 * split_token_from_name - separate a string of form <token>^<name>
72 * @op: operation being checked
73 * @args: string to parse (NOT NULL)
74 * @token: stores returned parsed token value (NOT NULL)
75 *
76 * Returns: start position of name after token else NULL on failure
77 */
78 static char *split_token_from_name(const char *op, char *args, u64 *token)
79 {
80 char *name;
81
82 *token = simple_strtoull(args, &name, 16);
83 if ((name == args) || *name != '^') {
84 AA_ERROR("%s: Invalid input '%s'", op, args);
85 return ERR_PTR(-EINVAL);
86 }
87
88 name++; /* skip ^ */
89 if (!*name)
90 name = NULL;
91 return name;
92 }
93
94 /**
95 * aa_setprocattr_chagnehat - handle procattr interface to change_hat
96 * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL)
97 * @size: size of the args
98 * @flags: set of flags governing behavior
99 *
100 * Returns: %0 or error code if change_hat fails
101 */
102 int aa_setprocattr_changehat(char *args, size_t size, int flags)
103 {
104 char *hat;
105 u64 token;
106 const char *hats[16]; /* current hard limit on # of names */
107 int count = 0;
108
109 hat = split_token_from_name(OP_CHANGE_HAT, args, &token);
110 if (IS_ERR(hat))
111 return PTR_ERR(hat);
112
113 if (!hat && !token) {
114 AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
115 return -EINVAL;
116 }
117
118 if (hat) {
119 /* set up hat name vector, args guaranteed null terminated
120 * at args[size] by setprocattr.
121 *
122 * If there are multiple hat names in the buffer each is
123 * separated by a \0. Ie. userspace writes them pre tokenized
124 */
125 char *end = args + size;
126 for (count = 0; (hat < end) && count < 16; ++count) {
127 char *next = hat + strlen(hat) + 1;
128 hats[count] = hat;
129 AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d hat '%s'\n"
130 , __func__, current->pid, token, count, hat);
131 hat = next;
132 }
133 } else
134 AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d Hat '%s'\n",
135 __func__, current->pid, token, count, "<NULL>");
136
137 return aa_change_hat(hats, count, token, flags);
138 }