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-rw-r--r--security/tomoyo/realpath.c292
1 files changed, 75 insertions, 217 deletions
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 18369d497eb8..cf7d61f781b9 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -14,9 +14,8 @@
#include <linux/mnt_namespace.h>
#include <linux/fs_struct.h>
#include <linux/hash.h>
-
+#include <linux/magic.h>
#include "common.h"
-#include "realpath.h"
/**
* tomoyo_encode: Convert binary string to ascii string.
@@ -89,30 +88,15 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname,
sp = dentry->d_op->d_dname(dentry, newname + offset,
newname_len - offset);
} else {
- /* Taken from d_namespace_path(). */
- struct path root;
- struct path ns_root = { };
- struct path tmp;
+ struct path ns_root = {.mnt = NULL, .dentry = NULL};
- read_lock(&current->fs->lock);
- root = current->fs->root;
- path_get(&root);
- read_unlock(&current->fs->lock);
- spin_lock(&vfsmount_lock);
- if (root.mnt && root.mnt->mnt_ns)
- ns_root.mnt = mntget(root.mnt->mnt_ns->root);
- if (ns_root.mnt)
- ns_root.dentry = dget(ns_root.mnt->mnt_root);
- spin_unlock(&vfsmount_lock);
spin_lock(&dcache_lock);
- tmp = ns_root;
- sp = __d_path(path, &tmp, newname, newname_len);
+ /* go to whatever namespace root we are under */
+ sp = __d_path(path, &ns_root, newname, newname_len);
spin_unlock(&dcache_lock);
- path_put(&root);
- path_put(&ns_root);
/* Prepend "/proc" prefix if using internal proc vfs mount. */
- if (!IS_ERR(sp) && (path->mnt->mnt_parent == path->mnt) &&
- (strcmp(path->mnt->mnt_sb->s_type->name, "proc") == 0)) {
+ if (!IS_ERR(sp) && (path->mnt->mnt_flags & MNT_INTERNAL) &&
+ (path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) {
sp -= 5;
if (sp >= newname)
memcpy(sp, "/proc", 5);
@@ -149,12 +133,12 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname,
*
* Returns the realpath of the given @path on success, NULL otherwise.
*
- * These functions use tomoyo_alloc(), so the caller must call tomoyo_free()
+ * These functions use kzalloc(), so the caller must call kfree()
* if these functions didn't return NULL.
*/
char *tomoyo_realpath_from_path(struct path *path)
{
- char *buf = tomoyo_alloc(sizeof(struct tomoyo_page_buffer));
+ char *buf = kzalloc(sizeof(struct tomoyo_page_buffer), GFP_KERNEL);
BUILD_BUG_ON(sizeof(struct tomoyo_page_buffer)
<= TOMOYO_MAX_PATHNAME_LEN - 1);
@@ -163,7 +147,7 @@ char *tomoyo_realpath_from_path(struct path *path)
if (tomoyo_realpath_from_path2(path, buf,
TOMOYO_MAX_PATHNAME_LEN - 1) == 0)
return buf;
- tomoyo_free(buf);
+ kfree(buf);
return NULL;
}
@@ -206,98 +190,47 @@ char *tomoyo_realpath_nofollow(const char *pathname)
}
/* Memory allocated for non-string data. */
-static unsigned int tomoyo_allocated_memory_for_elements;
-/* Quota for holding non-string data. */
-static unsigned int tomoyo_quota_for_elements;
+static atomic_t tomoyo_policy_memory_size;
+/* Quota for holding policy. */
+static unsigned int tomoyo_quota_for_policy;
/**
- * tomoyo_alloc_element - Allocate permanent memory for structures.
+ * tomoyo_memory_ok - Check memory quota.
*
- * @size: Size in bytes.
+ * @ptr: Pointer to allocated memory.
*
- * Returns pointer to allocated memory on success, NULL otherwise.
+ * Returns true on success, false otherwise.
*
- * Memory has to be zeroed.
- * The RAM is chunked, so NEVER try to kfree() the returned pointer.
+ * Caller holds tomoyo_policy_lock.
+ * Memory pointed by @ptr will be zeroed on success.
*/
-void *tomoyo_alloc_element(const unsigned int size)
+bool tomoyo_memory_ok(void *ptr)
{
- static char *buf;
- static DEFINE_MUTEX(lock);
- static unsigned int buf_used_len = PATH_MAX;
- char *ptr = NULL;
- /*Assumes sizeof(void *) >= sizeof(long) is true. */
- const unsigned int word_aligned_size
- = roundup(size, max(sizeof(void *), sizeof(long)));
- if (word_aligned_size > PATH_MAX)
- return NULL;
- mutex_lock(&lock);
- if (buf_used_len + word_aligned_size > PATH_MAX) {
- if (!tomoyo_quota_for_elements ||
- tomoyo_allocated_memory_for_elements
- + PATH_MAX <= tomoyo_quota_for_elements)
- ptr = kzalloc(PATH_MAX, GFP_KERNEL);
- if (!ptr) {
- printk(KERN_WARNING "ERROR: Out of memory "
- "for tomoyo_alloc_element().\n");
- if (!tomoyo_policy_loaded)
- panic("MAC Initialization failed.\n");
- } else {
- buf = ptr;
- tomoyo_allocated_memory_for_elements += PATH_MAX;
- buf_used_len = word_aligned_size;
- ptr = buf;
- }
- } else if (word_aligned_size) {
- int i;
- ptr = buf + buf_used_len;
- buf_used_len += word_aligned_size;
- for (i = 0; i < word_aligned_size; i++) {
- if (!ptr[i])
- continue;
- printk(KERN_ERR "WARNING: Reserved memory was tainted! "
- "The system might go wrong.\n");
- ptr[i] = '\0';
- }
+ int allocated_len = ptr ? ksize(ptr) : 0;
+ atomic_add(allocated_len, &tomoyo_policy_memory_size);
+ if (ptr && (!tomoyo_quota_for_policy ||
+ atomic_read(&tomoyo_policy_memory_size)
+ <= tomoyo_quota_for_policy)) {
+ memset(ptr, 0, allocated_len);
+ return true;
}
- mutex_unlock(&lock);
- return ptr;
+ printk(KERN_WARNING "ERROR: Out of memory "
+ "for tomoyo_alloc_element().\n");
+ if (!tomoyo_policy_loaded)
+ panic("MAC Initialization failed.\n");
+ return false;
}
-/* Memory allocated for string data in bytes. */
-static unsigned int tomoyo_allocated_memory_for_savename;
-/* Quota for holding string data in bytes. */
-static unsigned int tomoyo_quota_for_savename;
-
-/*
- * TOMOYO uses this hash only when appending a string into the string
- * table. Frequency of appending strings is very low. So we don't need
- * large (e.g. 64k) hash size. 256 will be sufficient.
- */
-#define TOMOYO_HASH_BITS 8
-#define TOMOYO_MAX_HASH (1u<<TOMOYO_HASH_BITS)
-
-/*
- * tomoyo_name_entry is a structure which is used for linking
- * "struct tomoyo_path_info" into tomoyo_name_list .
+/**
+ * tomoyo_memory_free - Free memory for elements.
*
- * Since tomoyo_name_list manages a list of strings which are shared by
- * multiple processes (whereas "struct tomoyo_path_info" inside
- * "struct tomoyo_path_info_with_data" is not shared), a reference counter will
- * be added to "struct tomoyo_name_entry" rather than "struct tomoyo_path_info"
- * when TOMOYO starts supporting garbage collector.
+ * @ptr: Pointer to allocated memory.
*/
-struct tomoyo_name_entry {
- struct list_head list;
- struct tomoyo_path_info entry;
-};
-
-/* Structure for available memory region. */
-struct tomoyo_free_memory_block_list {
- struct list_head list;
- char *ptr; /* Pointer to a free area. */
- int len; /* Length of the area. */
-};
+void tomoyo_memory_free(void *ptr)
+{
+ atomic_sub(ksize(ptr), &tomoyo_policy_memory_size);
+ kfree(ptr);
+}
/*
* tomoyo_name_list is used for holding string data used by TOMOYO.
@@ -305,87 +238,58 @@ struct tomoyo_free_memory_block_list {
* "/lib/libc-2.5.so"), TOMOYO shares string data in the form of
* "const struct tomoyo_path_info *".
*/
-static struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
+struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
+/* Lock for protecting tomoyo_name_list . */
+DEFINE_MUTEX(tomoyo_name_list_lock);
/**
- * tomoyo_save_name - Allocate permanent memory for string data.
+ * tomoyo_get_name - Allocate permanent memory for string data.
*
* @name: The string to store into the permernent memory.
*
* Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
- *
- * The RAM is shared, so NEVER try to modify or kfree() the returned name.
*/
-const struct tomoyo_path_info *tomoyo_save_name(const char *name)
+const struct tomoyo_path_info *tomoyo_get_name(const char *name)
{
- static LIST_HEAD(fmb_list);
- static DEFINE_MUTEX(lock);
struct tomoyo_name_entry *ptr;
unsigned int hash;
- /* fmb contains available size in bytes.
- fmb is removed from the fmb_list when fmb->len becomes 0. */
- struct tomoyo_free_memory_block_list *fmb;
int len;
- char *cp;
+ int allocated_len;
struct list_head *head;
if (!name)
return NULL;
len = strlen(name) + 1;
- if (len > TOMOYO_MAX_PATHNAME_LEN) {
- printk(KERN_WARNING "ERROR: Name too long "
- "for tomoyo_save_name().\n");
- return NULL;
- }
hash = full_name_hash((const unsigned char *) name, len - 1);
head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
-
- mutex_lock(&lock);
+ mutex_lock(&tomoyo_name_list_lock);
list_for_each_entry(ptr, head, list) {
- if (hash == ptr->entry.hash && !strcmp(name, ptr->entry.name))
- goto out;
- }
- list_for_each_entry(fmb, &fmb_list, list) {
- if (len <= fmb->len)
- goto ready;
+ if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name))
+ continue;
+ atomic_inc(&ptr->users);
+ goto out;
}
- if (!tomoyo_quota_for_savename ||
- tomoyo_allocated_memory_for_savename + PATH_MAX
- <= tomoyo_quota_for_savename)
- cp = kzalloc(PATH_MAX, GFP_KERNEL);
- else
- cp = NULL;
- fmb = kzalloc(sizeof(*fmb), GFP_KERNEL);
- if (!cp || !fmb) {
- kfree(cp);
- kfree(fmb);
+ ptr = kzalloc(sizeof(*ptr) + len, GFP_KERNEL);
+ allocated_len = ptr ? ksize(ptr) : 0;
+ if (!ptr || (tomoyo_quota_for_policy &&
+ atomic_read(&tomoyo_policy_memory_size) + allocated_len
+ > tomoyo_quota_for_policy)) {
+ kfree(ptr);
printk(KERN_WARNING "ERROR: Out of memory "
- "for tomoyo_save_name().\n");
+ "for tomoyo_get_name().\n");
if (!tomoyo_policy_loaded)
panic("MAC Initialization failed.\n");
ptr = NULL;
goto out;
}
- tomoyo_allocated_memory_for_savename += PATH_MAX;
- list_add(&fmb->list, &fmb_list);
- fmb->ptr = cp;
- fmb->len = PATH_MAX;
- ready:
- ptr = tomoyo_alloc_element(sizeof(*ptr));
- if (!ptr)
- goto out;
- ptr->entry.name = fmb->ptr;
- memmove(fmb->ptr, name, len);
+ atomic_add(allocated_len, &tomoyo_policy_memory_size);
+ ptr->entry.name = ((char *) ptr) + sizeof(*ptr);
+ memmove((char *) ptr->entry.name, name, len);
+ atomic_set(&ptr->users, 1);
tomoyo_fill_path_info(&ptr->entry);
- fmb->ptr += len;
- fmb->len -= len;
list_add_tail(&ptr->list, head);
- if (fmb->len == 0) {
- list_del(&fmb->list);
- kfree(fmb);
- }
out:
- mutex_unlock(&lock);
+ mutex_unlock(&tomoyo_name_list_lock);
return ptr ? &ptr->entry : NULL;
}
@@ -400,45 +304,14 @@ void __init tomoyo_realpath_init(void)
for (i = 0; i < TOMOYO_MAX_HASH; i++)
INIT_LIST_HEAD(&tomoyo_name_list[i]);
INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list);
- tomoyo_kernel_domain.domainname = tomoyo_save_name(TOMOYO_ROOT_NAME);
- list_add_tail(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
- down_read(&tomoyo_domain_list_lock);
+ tomoyo_kernel_domain.domainname = tomoyo_get_name(TOMOYO_ROOT_NAME);
+ /*
+ * tomoyo_read_lock() is not needed because this function is
+ * called before the first "delete" request.
+ */
+ list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
if (tomoyo_find_domain(TOMOYO_ROOT_NAME) != &tomoyo_kernel_domain)
panic("Can't register tomoyo_kernel_domain");
- up_read(&tomoyo_domain_list_lock);
-}
-
-/* Memory allocated for temporary purpose. */
-static atomic_t tomoyo_dynamic_memory_size;
-
-/**
- * tomoyo_alloc - Allocate memory for temporary purpose.
- *
- * @size: Size in bytes.
- *
- * Returns pointer to allocated memory on success, NULL otherwise.
- */
-void *tomoyo_alloc(const size_t size)
-{
- void *p = kzalloc(size, GFP_KERNEL);
- if (p)
- atomic_add(ksize(p), &tomoyo_dynamic_memory_size);
- return p;
-}
-
-/**
- * tomoyo_free - Release memory allocated by tomoyo_alloc().
- *
- * @p: Pointer returned by tomoyo_alloc(). May be NULL.
- *
- * Returns nothing.
- */
-void tomoyo_free(const void *p)
-{
- if (p) {
- atomic_sub(ksize(p), &tomoyo_dynamic_memory_size);
- kfree(p);
- }
}
/**
@@ -451,32 +324,19 @@ void tomoyo_free(const void *p)
int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
{
if (!head->read_eof) {
- const unsigned int shared
- = tomoyo_allocated_memory_for_savename;
- const unsigned int private
- = tomoyo_allocated_memory_for_elements;
- const unsigned int dynamic
- = atomic_read(&tomoyo_dynamic_memory_size);
+ const unsigned int policy
+ = atomic_read(&tomoyo_policy_memory_size);
char buffer[64];
memset(buffer, 0, sizeof(buffer));
- if (tomoyo_quota_for_savename)
- snprintf(buffer, sizeof(buffer) - 1,
- " (Quota: %10u)",
- tomoyo_quota_for_savename);
- else
- buffer[0] = '\0';
- tomoyo_io_printf(head, "Shared: %10u%s\n", shared, buffer);
- if (tomoyo_quota_for_elements)
+ if (tomoyo_quota_for_policy)
snprintf(buffer, sizeof(buffer) - 1,
" (Quota: %10u)",
- tomoyo_quota_for_elements);
+ tomoyo_quota_for_policy);
else
buffer[0] = '\0';
- tomoyo_io_printf(head, "Private: %10u%s\n", private, buffer);
- tomoyo_io_printf(head, "Dynamic: %10u\n", dynamic);
- tomoyo_io_printf(head, "Total: %10u\n",
- shared + private + dynamic);
+ tomoyo_io_printf(head, "Policy: %10u%s\n", policy, buffer);
+ tomoyo_io_printf(head, "Total: %10u\n", policy);
head->read_eof = true;
}
return 0;
@@ -494,9 +354,7 @@ int tomoyo_write_memory_quota(struct tomoyo_io_buffer *head)
char *data = head->write_buf;
unsigned int size;
- if (sscanf(data, "Shared: %u", &size) == 1)
- tomoyo_quota_for_savename = size;
- else if (sscanf(data, "Private: %u", &size) == 1)
- tomoyo_quota_for_elements = size;
+ if (sscanf(data, "Policy: %u", &size) == 1)
+ tomoyo_quota_for_policy = size;
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-11 12:24:59 +0100