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-rw-r--r--security/tomoyo/realpath.c231
1 files changed, 184 insertions, 47 deletions
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index d1e05b04771..d46922db054 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -1,9 +1,7 @@
1/* 1/*
2 * security/tomoyo/realpath.c 2 * security/tomoyo/realpath.c
3 * 3 *
4 * Pathname calculation functions for TOMOYO. 4 * Copyright (C) 2005-2011 NTT DATA CORPORATION
5 *
6 * Copyright (C) 2005-2010 NTT DATA CORPORATION
7 */ 5 */
8 6
9#include <linux/types.h> 7#include <linux/types.h>
@@ -70,6 +68,160 @@ char *tomoyo_encode(const char *str)
70} 68}
71 69
72/** 70/**
71 * tomoyo_get_absolute_path - Get the path of a dentry but ignores chroot'ed root.
72 *
73 * @path: Pointer to "struct path".
74 * @buffer: Pointer to buffer to return value in.
75 * @buflen: Sizeof @buffer.
76 *
77 * Returns the buffer on success, an error code otherwise.
78 *
79 * If dentry is a directory, trailing '/' is appended.
80 */
81static char *tomoyo_get_absolute_path(struct path *path, char * const buffer,
82 const int buflen)
83{
84 char *pos = ERR_PTR(-ENOMEM);
85 if (buflen >= 256) {
86 /* go to whatever namespace root we are under */
87 pos = d_absolute_path(path, buffer, buflen - 1);
88 if (!IS_ERR(pos) && *pos == '/' && pos[1]) {
89 struct inode *inode = path->dentry->d_inode;
90 if (inode && S_ISDIR(inode->i_mode)) {
91 buffer[buflen - 2] = '/';
92 buffer[buflen - 1] = '\0';
93 }
94 }
95 }
96 return pos;
97}
98
99/**
100 * tomoyo_get_dentry_path - Get the path of a dentry.
101 *
102 * @dentry: Pointer to "struct dentry".
103 * @buffer: Pointer to buffer to return value in.
104 * @buflen: Sizeof @buffer.
105 *
106 * Returns the buffer on success, an error code otherwise.
107 *
108 * If dentry is a directory, trailing '/' is appended.
109 */
110static char *tomoyo_get_dentry_path(struct dentry *dentry, char * const buffer,
111 const int buflen)
112{
113 char *pos = ERR_PTR(-ENOMEM);
114 if (buflen >= 256) {
115 pos = dentry_path_raw(dentry, buffer, buflen - 1);
116 if (!IS_ERR(pos) && *pos == '/' && pos[1]) {
117 struct inode *inode = dentry->d_inode;
118 if (inode && S_ISDIR(inode->i_mode)) {
119 buffer[buflen - 2] = '/';
120 buffer[buflen - 1] = '\0';
121 }
122 }
123 }
124 return pos;
125}
126
127/**
128 * tomoyo_get_local_path - Get the path of a dentry.
129 *
130 * @dentry: Pointer to "struct dentry".
131 * @buffer: Pointer to buffer to return value in.
132 * @buflen: Sizeof @buffer.
133 *
134 * Returns the buffer on success, an error code otherwise.
135 */
136static char *tomoyo_get_local_path(struct dentry *dentry, char * const buffer,
137 const int buflen)
138{
139 struct super_block *sb = dentry->d_sb;
140 char *pos = tomoyo_get_dentry_path(dentry, buffer, buflen);
141 if (IS_ERR(pos))
142 return pos;
143 /* Convert from $PID to self if $PID is current thread. */
144 if (sb->s_magic == PROC_SUPER_MAGIC && *pos == '/') {
145 char *ep;
146 const pid_t pid = (pid_t) simple_strtoul(pos + 1, &ep, 10);
147 if (*ep == '/' && pid && pid ==
148 task_tgid_nr_ns(current, sb->s_fs_info)) {
149 pos = ep - 5;
150 if (pos < buffer)
151 goto out;
152 memmove(pos, "/self", 5);
153 }
154 goto prepend_filesystem_name;
155 }
156 /* Use filesystem name for unnamed devices. */
157 if (!MAJOR(sb->s_dev))
158 goto prepend_filesystem_name;
159 {
160 struct inode *inode = sb->s_root->d_inode;
161 /*
162 * Use filesystem name if filesystem does not support rename()
163 * operation.
164 */
165 if (inode->i_op && !inode->i_op->rename)
166 goto prepend_filesystem_name;
167 }
168 /* Prepend device name. */
169 {
170 char name[64];
171 int name_len;
172 const dev_t dev = sb->s_dev;
173 name[sizeof(name) - 1] = '\0';
174 snprintf(name, sizeof(name) - 1, "dev(%u,%u):", MAJOR(dev),
175 MINOR(dev));
176 name_len = strlen(name);
177 pos -= name_len;
178 if (pos < buffer)
179 goto out;
180 memmove(pos, name, name_len);
181 return pos;
182 }
183 /* Prepend filesystem name. */
184prepend_filesystem_name:
185 {
186 const char *name = sb->s_type->name;
187 const int name_len = strlen(name);
188 pos -= name_len + 1;
189 if (pos < buffer)
190 goto out;
191 memmove(pos, name, name_len);
192 pos[name_len] = ':';
193 }
194 return pos;
195out:
196 return ERR_PTR(-ENOMEM);
197}
198
199/**
200 * tomoyo_get_socket_name - Get the name of a socket.
201 *
202 * @path: Pointer to "struct path".
203 * @buffer: Pointer to buffer to return value in.
204 * @buflen: Sizeof @buffer.
205 *
206 * Returns the buffer.
207 */
208static char *tomoyo_get_socket_name(struct path *path, char * const buffer,
209 const int buflen)
210{
211 struct inode *inode = path->dentry->d_inode;
212 struct socket *sock = inode ? SOCKET_I(inode) : NULL;
213 struct sock *sk = sock ? sock->sk : NULL;
214 if (sk) {
215 snprintf(buffer, buflen, "socket:[family=%u:type=%u:"
216 "protocol=%u]", sk->sk_family, sk->sk_type,
217 sk->sk_protocol);
218 } else {
219 snprintf(buffer, buflen, "socket:[unknown]");
220 }
221 return buffer;
222}
223
224/**
73 * tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root. 225 * tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root.
74 * 226 *
75 * @path: Pointer to "struct path". 227 * @path: Pointer to "struct path".
@@ -90,55 +242,50 @@ char *tomoyo_realpath_from_path(struct path *path)
90 char *name = NULL; 242 char *name = NULL;
91 unsigned int buf_len = PAGE_SIZE / 2; 243 unsigned int buf_len = PAGE_SIZE / 2;
92 struct dentry *dentry = path->dentry; 244 struct dentry *dentry = path->dentry;
93 bool is_dir; 245 struct super_block *sb;
94 if (!dentry) 246 if (!dentry)
95 return NULL; 247 return NULL;
96 is_dir = dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode); 248 sb = dentry->d_sb;
97 while (1) { 249 while (1) {
98 struct path ns_root = { .mnt = NULL, .dentry = NULL };
99 char *pos; 250 char *pos;
251 struct inode *inode;
100 buf_len <<= 1; 252 buf_len <<= 1;
101 kfree(buf); 253 kfree(buf);
102 buf = kmalloc(buf_len, GFP_NOFS); 254 buf = kmalloc(buf_len, GFP_NOFS);
103 if (!buf) 255 if (!buf)
104 break; 256 break;
257 /* To make sure that pos is '\0' terminated. */
258 buf[buf_len - 1] = '\0';
105 /* Get better name for socket. */ 259 /* Get better name for socket. */
106 if (dentry->d_sb && dentry->d_sb->s_magic == SOCKFS_MAGIC) { 260 if (sb->s_magic == SOCKFS_MAGIC) {
107 struct inode *inode = dentry->d_inode; 261 pos = tomoyo_get_socket_name(path, buf, buf_len - 1);
108 struct socket *sock = inode ? SOCKET_I(inode) : NULL; 262 goto encode;
109 struct sock *sk = sock ? sock->sk : NULL;
110 if (sk) {
111 snprintf(buf, buf_len - 1, "socket:[family=%u:"
112 "type=%u:protocol=%u]", sk->sk_family,
113 sk->sk_type, sk->sk_protocol);
114 } else {
115 snprintf(buf, buf_len - 1, "socket:[unknown]");
116 }
117 name = tomoyo_encode(buf);
118 break;
119 } 263 }
120 /* For "socket:[\$]" and "pipe:[\$]". */ 264 /* For "pipe:[\$]". */
121 if (dentry->d_op && dentry->d_op->d_dname) { 265 if (dentry->d_op && dentry->d_op->d_dname) {
122 pos = dentry->d_op->d_dname(dentry, buf, buf_len - 1); 266 pos = dentry->d_op->d_dname(dentry, buf, buf_len - 1);
123 if (IS_ERR(pos)) 267 goto encode;
124 continue;
125 name = tomoyo_encode(pos);
126 break;
127 } 268 }
128 /* If we don't have a vfsmount, we can't calculate. */ 269 inode = sb->s_root->d_inode;
129 if (!path->mnt) 270 /*
130 break; 271 * Get local name for filesystems without rename() operation
131 /* go to whatever namespace root we are under */ 272 * or dentry without vfsmount.
132 pos = __d_path(path, &ns_root, buf, buf_len); 273 */
133 /* Prepend "/proc" prefix if using internal proc vfs mount. */ 274 if (!path->mnt || (inode->i_op && !inode->i_op->rename))
134 if (!IS_ERR(pos) && (path->mnt->mnt_flags & MNT_INTERNAL) && 275 pos = tomoyo_get_local_path(path->dentry, buf,
135 (path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) { 276 buf_len - 1);
136 pos -= 5; 277 /* Get absolute name for the rest. */
137 if (pos >= buf) 278 else {
138 memcpy(pos, "/proc", 5); 279 pos = tomoyo_get_absolute_path(path, buf, buf_len - 1);
139 else 280 /*
140 pos = ERR_PTR(-ENOMEM); 281 * Fall back to local name if absolute name is not
282 * available.
283 */
284 if (pos == ERR_PTR(-EINVAL))
285 pos = tomoyo_get_local_path(path->dentry, buf,
286 buf_len - 1);
141 } 287 }
288encode:
142 if (IS_ERR(pos)) 289 if (IS_ERR(pos))
143 continue; 290 continue;
144 name = tomoyo_encode(pos); 291 name = tomoyo_encode(pos);
@@ -147,16 +294,6 @@ char *tomoyo_realpath_from_path(struct path *path)
147 kfree(buf); 294 kfree(buf);
148 if (!name) 295 if (!name)
149 tomoyo_warn_oom(__func__); 296 tomoyo_warn_oom(__func__);
150 else if (is_dir && *name) {
151 /* Append trailing '/' if dentry is a directory. */
152 char *pos = name + strlen(name) - 1;
153 if (*pos != '/')
154 /*
155 * This is OK because tomoyo_encode() reserves space
156 * for appending "/".
157 */
158 *++pos = '/';
159 }
160 return name; 297 return name;
161} 298}
162 299