| 1 |
/* |
| 2 |
* fs/sakura_mount.c |
| 3 |
* |
| 4 |
* Implementation of the Domain-Free Mandatory Access Control. |
| 5 |
* |
| 6 |
* Copyright (C) 2005-2008 NTT DATA CORPORATION |
| 7 |
* |
| 8 |
* Version: 1.5.5 2008/09/03 |
| 9 |
* |
| 10 |
* This file is applicable to both 2.4.30 and 2.6.11 and later. |
| 11 |
* See README.ccs for ChangeLog. |
| 12 |
* |
| 13 |
*/ |
| 14 |
/***** SAKURA Linux start. *****/ |
| 15 |
|
| 16 |
#include <linux/ccs_common.h> |
| 17 |
#include <linux/sakura.h> |
| 18 |
#include <linux/realpath.h> |
| 19 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20) |
| 20 |
#include <linux/namespace.h> |
| 21 |
#endif |
| 22 |
|
| 23 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 15) |
| 24 |
#define MS_UNBINDABLE (1<<17) /* change to unbindable */ |
| 25 |
#define MS_PRIVATE (1<<18) /* change to private */ |
| 26 |
#define MS_SLAVE (1<<19) /* change to slave */ |
| 27 |
#define MS_SHARED (1<<20) /* change to shared */ |
| 28 |
#endif |
| 29 |
|
| 30 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 0) |
| 31 |
#include <linux/namei.h> |
| 32 |
#else |
| 33 |
static inline void module_put(struct module *module) |
| 34 |
{ |
| 35 |
if (module) __MOD_DEC_USE_COUNT(module); |
| 36 |
} |
| 37 |
#endif |
| 38 |
|
| 39 |
extern const char *ccs_log_level; |
| 40 |
|
| 41 |
/***** KEYWORDS for mount restrictions. *****/ |
| 42 |
|
| 43 |
#define MOUNT_BIND_KEYWORD "--bind" /* Allow to call 'mount --bind /source_dir /dest_dir' */ |
| 44 |
#define MOUNT_MOVE_KEYWORD "--move" /* Allow to call 'mount --move /old_dir /new_dir ' */ |
| 45 |
#define MOUNT_REMOUNT_KEYWORD "--remount" /* Allow to call 'mount -o remount /dir ' */ |
| 46 |
#define MOUNT_MAKE_UNBINDABLE_KEYWORD "--make-unbindable" /* Allow to call 'mount --make-unbindable /dir' */ |
| 47 |
#define MOUNT_MAKE_PRIVATE_KEYWORD "--make-private" /* Allow to call 'mount --make-private /dir' */ |
| 48 |
#define MOUNT_MAKE_SLAVE_KEYWORD "--make-slave" /* Allow to call 'mount --make-slave /dir' */ |
| 49 |
#define MOUNT_MAKE_SHARED_KEYWORD "--make-shared" /* Allow to call 'mount --make-shared /dir' */ |
| 50 |
|
| 51 |
/***** The structure for mount restrictions. *****/ |
| 52 |
|
| 53 |
struct mount_entry { |
| 54 |
struct mount_entry *next; |
| 55 |
const struct path_info *dev_name; |
| 56 |
const struct path_info *dir_name; |
| 57 |
const struct path_info *fs_type; |
| 58 |
unsigned long flags; |
| 59 |
int is_deleted; |
| 60 |
}; |
| 61 |
|
| 62 |
/************************* MOUNT RESTRICTION HANDLER *************************/ |
| 63 |
|
| 64 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24) |
| 65 |
static void put_filesystem(struct file_system_type *fs) |
| 66 |
{ |
| 67 |
module_put(fs->owner); |
| 68 |
} |
| 69 |
#endif |
| 70 |
|
| 71 |
static struct mount_entry *mount_list = NULL; |
| 72 |
|
| 73 |
static int AddMountACL(const char *dev_name, const char *dir_name, const char *fs_type, const unsigned long flags, const int is_delete) |
| 74 |
{ |
| 75 |
struct mount_entry *new_entry, *ptr; |
| 76 |
const struct path_info *fs, *dev, *dir; |
| 77 |
static DECLARE_MUTEX(lock); |
| 78 |
int error = -ENOMEM; |
| 79 |
if ((fs = SaveName(fs_type)) == NULL) return -EINVAL; |
| 80 |
if (!dev_name) dev_name = "<NULL>"; /* Map dev_name to "<NULL>" for if no dev_name given. */ |
| 81 |
if (strcmp(fs->name, MOUNT_REMOUNT_KEYWORD) == 0) dev_name = "any"; /* Fix dev_name to "any" for remount permission. */ |
| 82 |
if (strcmp(fs->name, MOUNT_MAKE_UNBINDABLE_KEYWORD) == 0 || |
| 83 |
strcmp(fs->name, MOUNT_MAKE_PRIVATE_KEYWORD) == 0 || |
| 84 |
strcmp(fs->name, MOUNT_MAKE_SLAVE_KEYWORD) == 0 || |
| 85 |
strcmp(fs->name, MOUNT_MAKE_SHARED_KEYWORD) == 0) dev_name = "any"; |
| 86 |
if (!IsCorrectPath(dev_name, 0, 0, 0, __FUNCTION__) || !IsCorrectPath(dir_name, 0, 0, 0, __FUNCTION__)) return -EINVAL; |
| 87 |
if ((dev = SaveName(dev_name)) == NULL || (dir = SaveName(dir_name)) == NULL) return -ENOMEM; |
| 88 |
down(&lock); |
| 89 |
for (ptr = mount_list; ptr; ptr = ptr->next) { |
| 90 |
if (ptr->flags != flags || pathcmp(ptr->dev_name, dev) || pathcmp(ptr->dir_name, dir) || pathcmp(ptr->fs_type, fs)) continue; |
| 91 |
error = 0; |
| 92 |
if (is_delete) { |
| 93 |
ptr->is_deleted = 1; |
| 94 |
goto out; |
| 95 |
} else { |
| 96 |
if (ptr->is_deleted) { |
| 97 |
ptr->is_deleted = 0; |
| 98 |
goto update; |
| 99 |
} |
| 100 |
goto out; /* No changes. */ |
| 101 |
} |
| 102 |
} |
| 103 |
if (is_delete) { |
| 104 |
error = -ENOENT; |
| 105 |
goto out; |
| 106 |
} |
| 107 |
if ((new_entry = alloc_element(sizeof(*new_entry))) == NULL) goto out; |
| 108 |
new_entry->dev_name = dev; |
| 109 |
new_entry->dir_name = dir; |
| 110 |
new_entry->fs_type = fs; |
| 111 |
new_entry->flags = flags; |
| 112 |
mb(); /* Avoid out-of-order execution. */ |
| 113 |
if ((ptr = mount_list) != NULL) { |
| 114 |
while (ptr->next) ptr = ptr->next; ptr->next = new_entry; |
| 115 |
} else { |
| 116 |
mount_list = new_entry; |
| 117 |
} |
| 118 |
error = 0; |
| 119 |
ptr = new_entry; |
| 120 |
update: |
| 121 |
{ |
| 122 |
struct file_system_type *type = NULL; |
| 123 |
if (strcmp(fs->name, MOUNT_REMOUNT_KEYWORD) == 0) { |
| 124 |
printk("%sAllow remount %s with options 0x%lX.\n", ccs_log_level, dir->name, ptr->flags); |
| 125 |
} else if (strcmp(fs->name, MOUNT_BIND_KEYWORD) == 0 || strcmp(fs->name, MOUNT_MOVE_KEYWORD) == 0) { |
| 126 |
printk("%sAllow mount %s %s %s with options 0x%lX\n", ccs_log_level, fs->name, dev->name, dir->name, ptr->flags); |
| 127 |
} else if (strcmp(fs->name, MOUNT_MAKE_UNBINDABLE_KEYWORD) == 0 || |
| 128 |
strcmp(fs->name, MOUNT_MAKE_PRIVATE_KEYWORD) == 0 || |
| 129 |
strcmp(fs->name, MOUNT_MAKE_SLAVE_KEYWORD) == 0 || |
| 130 |
strcmp(fs->name, MOUNT_MAKE_SHARED_KEYWORD) == 0) { |
| 131 |
printk("%sAllow mount %s %s with options 0x%lX.\n", ccs_log_level, fs->name, dir->name, ptr->flags); |
| 132 |
} else if ((type = get_fs_type(fs->name)) != NULL && (type->fs_flags & FS_REQUIRES_DEV) != 0) { |
| 133 |
printk("%sAllow mount -t %s %s %s with options 0x%lX.\n", ccs_log_level, fs->name, dev->name, dir->name, ptr->flags); |
| 134 |
} else { |
| 135 |
printk("%sAllow mount %s on %s with options 0x%lX.\n", ccs_log_level, fs->name, dir->name, ptr->flags); |
| 136 |
} |
| 137 |
if (type) put_filesystem(type); |
| 138 |
} |
| 139 |
out: |
| 140 |
up(&lock); |
| 141 |
return error; |
| 142 |
} |
| 143 |
|
| 144 |
static int CheckMountPermission2(char *dev_name, char *dir_name, char *type, unsigned long flags) |
| 145 |
{ |
| 146 |
const int is_enforce = CheckCCSEnforce(CCS_SAKURA_RESTRICT_MOUNT); |
| 147 |
int error = -EPERM; |
| 148 |
if (!CheckCCSFlags(CCS_SAKURA_RESTRICT_MOUNT)) return 0; |
| 149 |
if (!type) type = "<NULL>"; |
| 150 |
if ((flags & MS_MGC_MSK) == MS_MGC_VAL) flags &= ~MS_MGC_MSK; |
| 151 |
switch (flags & (MS_REMOUNT | MS_MOVE | MS_BIND)) { |
| 152 |
case MS_REMOUNT: |
| 153 |
case MS_MOVE: |
| 154 |
case MS_BIND: |
| 155 |
case 0: |
| 156 |
break; |
| 157 |
default: |
| 158 |
printk("SAKURA-ERROR: %s%s%sare given for single mount operation.\n", |
| 159 |
flags & MS_REMOUNT ? "'remount' " : "", |
| 160 |
flags & MS_MOVE ? "'move' " : "", |
| 161 |
flags & MS_BIND ? "'bind' " : ""); |
| 162 |
return -EINVAL; |
| 163 |
} |
| 164 |
switch (flags & (MS_UNBINDABLE | MS_PRIVATE | MS_SLAVE | MS_SHARED)) { |
| 165 |
case MS_UNBINDABLE: |
| 166 |
case MS_PRIVATE: |
| 167 |
case MS_SLAVE: |
| 168 |
case MS_SHARED: |
| 169 |
case 0: |
| 170 |
break; |
| 171 |
default: |
| 172 |
printk("SAKURA-ERROR: %s%s%s%sare given for single mount operation.\n", |
| 173 |
flags & MS_UNBINDABLE ? "'unbindable' " : "", |
| 174 |
flags & MS_PRIVATE ? "'private' " : "", |
| 175 |
flags & MS_SLAVE ? "'slave' " : "", |
| 176 |
flags & MS_SHARED ? "'shared' " : ""); |
| 177 |
return -EINVAL; |
| 178 |
} |
| 179 |
if (flags & MS_REMOUNT) { |
| 180 |
error = CheckMountPermission2(dev_name, dir_name, MOUNT_REMOUNT_KEYWORD, flags & ~MS_REMOUNT); |
| 181 |
} else if (flags & MS_MOVE) { |
| 182 |
error = CheckMountPermission2(dev_name, dir_name, MOUNT_MOVE_KEYWORD, flags & ~MS_MOVE); |
| 183 |
} else if (flags & MS_BIND) { |
| 184 |
error = CheckMountPermission2(dev_name, dir_name, MOUNT_BIND_KEYWORD, flags & ~MS_BIND); |
| 185 |
} else if (flags & MS_UNBINDABLE) { |
| 186 |
error = CheckMountPermission2(dev_name, dir_name, MOUNT_MAKE_UNBINDABLE_KEYWORD, flags & ~MS_UNBINDABLE); |
| 187 |
} else if (flags & MS_PRIVATE) { |
| 188 |
error = CheckMountPermission2(dev_name, dir_name, MOUNT_MAKE_PRIVATE_KEYWORD, flags & ~MS_PRIVATE); |
| 189 |
} else if (flags & MS_SLAVE) { |
| 190 |
error = CheckMountPermission2(dev_name, dir_name, MOUNT_MAKE_SLAVE_KEYWORD, flags & ~MS_SLAVE); |
| 191 |
} else if (flags & MS_SHARED) { |
| 192 |
error = CheckMountPermission2(dev_name, dir_name, MOUNT_MAKE_SHARED_KEYWORD, flags & ~MS_SHARED); |
| 193 |
} else { |
| 194 |
struct mount_entry *ptr; |
| 195 |
struct file_system_type *fstype = NULL; |
| 196 |
const char *requested_dir_name = NULL; |
| 197 |
const char *requested_dev_name = NULL; |
| 198 |
struct path_info rdev, rdir; |
| 199 |
int need_dev = 0; |
| 200 |
|
| 201 |
if ((requested_dir_name = realpath(dir_name)) == NULL) { |
| 202 |
error = -ENOENT; |
| 203 |
goto cleanup; |
| 204 |
} |
| 205 |
rdir.name = requested_dir_name; |
| 206 |
fill_path_info(&rdir); |
| 207 |
|
| 208 |
/* Compare fs name. */ |
| 209 |
if (strcmp(type, MOUNT_REMOUNT_KEYWORD) == 0) { |
| 210 |
/* Needn't to resolve dev_name */ |
| 211 |
} else if (strcmp(type, MOUNT_MAKE_UNBINDABLE_KEYWORD) == 0 || |
| 212 |
strcmp(type, MOUNT_MAKE_PRIVATE_KEYWORD) == 0 || |
| 213 |
strcmp(type, MOUNT_MAKE_SLAVE_KEYWORD) == 0 || |
| 214 |
strcmp(type, MOUNT_MAKE_SHARED_KEYWORD) == 0) { |
| 215 |
/* Needn't to resolve dev_name */ |
| 216 |
} else if (strcmp(type, MOUNT_BIND_KEYWORD) == 0 || strcmp(type, MOUNT_MOVE_KEYWORD) == 0) { |
| 217 |
if ((requested_dev_name = realpath(dev_name)) == NULL) { |
| 218 |
error = -ENOENT; |
| 219 |
goto cleanup; |
| 220 |
} |
| 221 |
rdev.name = requested_dev_name; |
| 222 |
fill_path_info(&rdev); |
| 223 |
need_dev = -1; /* dev_name is a directory */ |
| 224 |
} else if ((fstype = get_fs_type(type)) != NULL) { |
| 225 |
if (fstype->fs_flags & FS_REQUIRES_DEV) { |
| 226 |
if ((requested_dev_name = realpath(dev_name)) == NULL) { |
| 227 |
error = -ENOENT; |
| 228 |
goto cleanup; |
| 229 |
} |
| 230 |
rdev.name = requested_dev_name; |
| 231 |
fill_path_info(&rdev); |
| 232 |
need_dev = 1; /* dev_name is a block device file */ |
| 233 |
} |
| 234 |
} else { |
| 235 |
error = -ENODEV; |
| 236 |
goto cleanup; |
| 237 |
} |
| 238 |
for (ptr = mount_list; ptr; ptr = ptr->next) { |
| 239 |
if (ptr->is_deleted) continue; |
| 240 |
|
| 241 |
/* Compare options */ |
| 242 |
if (ptr->flags != flags) continue; |
| 243 |
|
| 244 |
/* Compare fs name. */ |
| 245 |
if (strcmp(type, ptr->fs_type->name)) continue; |
| 246 |
|
| 247 |
/* Compare mount point. */ |
| 248 |
if (PathMatchesToPattern(&rdir, ptr->dir_name) == 0) continue; |
| 249 |
|
| 250 |
/* Compare device name. */ |
| 251 |
if (requested_dev_name && PathMatchesToPattern(&rdev, ptr->dev_name) == 0) continue; |
| 252 |
|
| 253 |
/* OK. */ |
| 254 |
error = 0; |
| 255 |
|
| 256 |
if (need_dev > 0) { |
| 257 |
printk(KERN_DEBUG "SAKURA-NOTICE: 'mount -t %s %s %s 0x%lX' accepted.\n", type, requested_dev_name, requested_dir_name, flags); |
| 258 |
} else if (need_dev < 0) { |
| 259 |
printk(KERN_DEBUG "SAKURA-NOTICE: 'mount %s %s %s 0x%lX' accepted.\n", type, requested_dev_name, requested_dir_name, flags); |
| 260 |
} else if (strcmp(type, MOUNT_REMOUNT_KEYWORD) == 0) { |
| 261 |
printk(KERN_DEBUG "SAKURA-NOTICE: 'mount -o remount %s 0x%lX' accepted.\n", requested_dir_name, flags); |
| 262 |
} else if (strcmp(type, MOUNT_MAKE_UNBINDABLE_KEYWORD) == 0 || |
| 263 |
strcmp(type, MOUNT_MAKE_PRIVATE_KEYWORD) == 0 || |
| 264 |
strcmp(type, MOUNT_MAKE_SLAVE_KEYWORD) == 0 || |
| 265 |
strcmp(type, MOUNT_MAKE_SHARED_KEYWORD) == 0) { |
| 266 |
printk(KERN_DEBUG "SAKURA-NOTICE: 'mount %s %s 0x%lX' accepted.\n", type, requested_dir_name, flags); |
| 267 |
} else { |
| 268 |
printk(KERN_DEBUG "SAKURA-NOTICE: 'mount %s on %s 0x%lX' accepted.\n", type, requested_dir_name, flags); |
| 269 |
} |
| 270 |
break; |
| 271 |
} |
| 272 |
if (error) { |
| 273 |
const char *realname1 = realpath(dev_name), *realname2 = realpath(dir_name), *exename = GetEXE(); |
| 274 |
if (strcmp(type, MOUNT_REMOUNT_KEYWORD) == 0) { |
| 275 |
printk("SAKURA-%s: mount -o remount %s 0x%lX (pid=%d:exe=%s): Permission denied.\n", GetMSG(is_enforce), realname2 ? realname2 : dir_name, flags, current->pid, exename); |
| 276 |
if (is_enforce && CheckSupervisor("# %s is requesting\nmount -o remount %s 0x%lX\n", exename, realname2 ? realname2 : dir_name, flags) == 0) error = 0; |
| 277 |
} else if (strcmp(type, MOUNT_BIND_KEYWORD) == 0 || strcmp(type, MOUNT_MOVE_KEYWORD) == 0) { |
| 278 |
printk("SAKURA-%s: mount %s %s %s 0x%lX (pid=%d:exe=%s): Permission denied.\n", GetMSG(is_enforce), type, realname1 ? realname1 : dev_name, realname2 ? realname2 : dir_name, flags, current->pid, exename); |
| 279 |
if (is_enforce && CheckSupervisor("# %s is requesting\nmount %s %s %s 0x%lX\n", exename, type, realname1 ? realname1 : dev_name, realname2 ? realname2 : dir_name, flags) == 0) error = 0; |
| 280 |
} else if (strcmp(type, MOUNT_MAKE_UNBINDABLE_KEYWORD) == 0 || |
| 281 |
strcmp(type, MOUNT_MAKE_PRIVATE_KEYWORD) == 0 || |
| 282 |
strcmp(type, MOUNT_MAKE_SLAVE_KEYWORD) == 0 || |
| 283 |
strcmp(type, MOUNT_MAKE_SHARED_KEYWORD) == 0) { |
| 284 |
printk("SAKURA-%s: mount %s %s 0x%lX (pid=%d:exe=%s): Permission denied.\n", GetMSG(is_enforce), type, realname2 ? realname2 : dir_name, flags, current->pid, exename); |
| 285 |
if (is_enforce && CheckSupervisor("# %s is requesting\nmount %s %s 0x%lX", exename, type, realname2 ? realname2 : dir_name, flags) == 0) error = 0; |
| 286 |
} else { |
| 287 |
printk("SAKURA-%s: mount -t %s %s %s 0x%lX (pid=%d:exe=%s): Permission denied.\n", GetMSG(is_enforce), type, realname1 ? realname1 : dev_name, realname2 ? realname2 : dir_name, flags, current->pid, exename); |
| 288 |
if (is_enforce && CheckSupervisor("# %s is requesting\nmount -t %s %s %s 0x%lX\n", exename, type, realname1 ? realname1 : dev_name, realname2 ? realname2 : dir_name, flags) == 0) error = 0; |
| 289 |
} |
| 290 |
ccs_free(exename); |
| 291 |
ccs_free(realname2); |
| 292 |
ccs_free(realname1); |
| 293 |
} |
| 294 |
if (error && !is_enforce && CheckCCSAccept(CCS_SAKURA_RESTRICT_MOUNT, NULL)) { |
| 295 |
AddMountACL(need_dev ? requested_dev_name : dev_name, requested_dir_name, type, flags, 0); |
| 296 |
UpdateCounter(CCS_UPDATES_COUNTER_SYSTEM_POLICY); |
| 297 |
} |
| 298 |
cleanup: |
| 299 |
ccs_free(requested_dev_name); |
| 300 |
ccs_free(requested_dir_name); |
| 301 |
if (fstype) put_filesystem(fstype); |
| 302 |
} |
| 303 |
if (!is_enforce) error = 0; |
| 304 |
return error; |
| 305 |
} |
| 306 |
|
| 307 |
/* This is a wrapper to allow use of 1.4.x patch for 1.5.x . */ |
| 308 |
int CheckMountPermission(char *dev_name, char *dir_name, char *type, const unsigned long *flags) |
| 309 |
{ |
| 310 |
return CheckMountPermission2(dev_name, dir_name, type, *flags); |
| 311 |
} |
| 312 |
|
| 313 |
int AddMountPolicy(char *data, const int is_delete) |
| 314 |
{ |
| 315 |
char *cp, *cp2; |
| 316 |
const char *fs, *dev, *dir; |
| 317 |
unsigned long flags = 0; |
| 318 |
cp2 = data; if ((cp = strchr(cp2, ' ')) == NULL) return -EINVAL; *cp = '\0'; dev = cp2; |
| 319 |
cp2 = cp + 1; if ((cp = strchr(cp2, ' ')) == NULL) return -EINVAL; *cp = '\0'; dir = cp2; |
| 320 |
cp2 = cp + 1; if ((cp = strchr(cp2, ' ')) == NULL) return -EINVAL; *cp = '\0'; fs = cp2; |
| 321 |
flags = simple_strtoul(cp + 1, NULL, 0); |
| 322 |
return AddMountACL(dev, dir, fs, flags, is_delete); |
| 323 |
} |
| 324 |
|
| 325 |
int ReadMountPolicy(struct io_buffer *head) |
| 326 |
{ |
| 327 |
struct mount_entry *ptr = head->read_var2; |
| 328 |
if (!ptr) ptr = mount_list; |
| 329 |
while (ptr) { |
| 330 |
head->read_var2 = ptr; |
| 331 |
if (ptr->is_deleted == 0 && io_printf(head, KEYWORD_ALLOW_MOUNT "%s %s %s 0x%lX\n", ptr->dev_name->name, ptr->dir_name->name, ptr->fs_type->name, ptr->flags)) break; |
| 332 |
ptr = ptr->next; |
| 333 |
} |
| 334 |
return ptr ? -ENOMEM : 0; |
| 335 |
} |
| 336 |
|
| 337 |
/***** SAKURA Linux end. *****/ |
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