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