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 * @newline: indicates that a newline should be added 24 * 25 * Requires: label != NULL && string != NULL 26 * 27 * Creates a string containing the label information for @label. 28 * 29 * Returns: size of string placed in @string else error code on failure 30 */ 31 int aa_getprocattr(struct aa_label *label, char **string, bool newline) 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 kfree(*string); 58 *string = NULL; 59 aa_put_ns(current_ns); 60 return len; 61 } 62 63 if (newline) 64 (*string)[len++] = '\n'; 65 (*string)[len] = 0; 66 67 aa_put_ns(current_ns); 68 return len; 69 } 70 71 /** 72 * split_token_from_name - separate a string of form <token>^<name> 73 * @op: operation being checked 74 * @args: string to parse (NOT NULL) 75 * @token: stores returned parsed token value (NOT NULL) 76 * 77 * Returns: start position of name after token else NULL on failure 78 */ 79 static char *split_token_from_name(const char *op, char *args, u64 *token) 80 { 81 char *name; 82 83 *token = simple_strtoull(args, &name, 16); 84 if ((name == args) || *name != '^') { 85 AA_ERROR("%s: Invalid input '%s'", op, args); 86 return ERR_PTR(-EINVAL); 87 } 88 89 name++; /* skip ^ */ 90 if (!*name) 91 name = NULL; 92 return name; 93 } 94 95 /** 96 * aa_setprocattr_changehat - handle procattr interface to change_hat 97 * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL) 98 * @size: size of the args 99 * @flags: set of flags governing behavior 100 * 101 * Returns: %0 or error code if change_hat fails 102 */ 103 int aa_setprocattr_changehat(char *args, size_t size, int flags) 104 { 105 char *hat; 106 u64 token; 107 const char *hats[16]; /* current hard limit on # of names */ 108 int count = 0; 109 110 hat = split_token_from_name(OP_CHANGE_HAT, args, &token); 111 if (IS_ERR(hat)) 112 return PTR_ERR(hat); 113 114 if (!hat && !token) { 115 AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic"); 116 return -EINVAL; 117 } 118 119 if (hat) { 120 /* set up hat name vector, args guaranteed null terminated 121 * at args[size] by setprocattr. 122 * 123 * If there are multiple hat names in the buffer each is 124 * separated by a \0. Ie. userspace writes them pre tokenized 125 */ 126 char *end = args + size; 127 for (count = 0; (hat < end) && count < 16; ++count) { 128 char *next = hat + strlen(hat) + 1; 129 hats[count] = hat; 130 AA_DEBUG(DEBUG_DOMAIN, 131 "%s: (pid %d) Magic 0x%llx count %d hat '%s'\n" 132 , __func__, current->pid, token, count, hat); 133 hat = next; 134 } 135 } else 136 AA_DEBUG(DEBUG_DOMAIN, 137 "%s: (pid %d) Magic 0x%llx count %d Hat '%s'\n", 138 __func__, current->pid, token, count, "<NULL>"); 139 140 return aa_change_hat(hats, count, token, flags); 141 } 142