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