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Diffstat (limited to 'security/tomoyo/realpath.c')
-rw-r--r--security/tomoyo/realpath.c136
1 files changed, 37 insertions, 99 deletions
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 18369d497eb8..54226d5be493 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -14,6 +14,7 @@
#include <linux/mnt_namespace.h>
#include <linux/fs_struct.h>
#include <linux/hash.h>
+#include <linux/magic.h>
#include "common.h"
#include "realpath.h"
@@ -112,7 +113,7 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname,
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)) {
+ (path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) {
sp -= 5;
if (sp >= newname)
memcpy(sp, "/proc", 5);
@@ -211,57 +212,32 @@ static unsigned int tomoyo_allocated_memory_for_elements;
static unsigned int tomoyo_quota_for_elements;
/**
- * 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;
+ bool result = false;
+ if (!ptr || (tomoyo_quota_for_elements &&
+ tomoyo_allocated_memory_for_elements
+ + allocated_len > tomoyo_quota_for_elements)) {
+ printk(KERN_WARNING "ERROR: Out of memory "
+ "for tomoyo_alloc_element().\n");
+ if (!tomoyo_policy_loaded)
+ panic("MAC Initialization failed.\n");
+ } else {
+ result = true;
+ tomoyo_allocated_memory_for_elements += allocated_len;
+ memset(ptr, 0, allocated_len);
}
- mutex_unlock(&lock);
- return ptr;
+ return result;
}
/* Memory allocated for string data in bytes. */
@@ -292,13 +268,6 @@ struct tomoyo_name_entry {
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. */
-};
-
/*
* tomoyo_name_list is used for holding string data used by TOMOYO.
* Since same string data is likely used for multiple times (e.g.
@@ -313,52 +282,32 @@ static struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
* @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)
{
- 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);
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 (!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_savename &&
+ tomoyo_allocated_memory_for_savename + allocated_len
+ > tomoyo_quota_for_savename)) {
+ kfree(ptr);
printk(KERN_WARNING "ERROR: Out of memory "
"for tomoyo_save_name().\n");
if (!tomoyo_policy_loaded)
@@ -366,24 +315,11 @@ const struct tomoyo_path_info *tomoyo_save_name(const char *name)
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);
+ tomoyo_allocated_memory_for_savename += allocated_len;
+ ptr->entry.name = ((char *) ptr) + sizeof(*ptr);
+ memmove((char *) ptr->entry.name, name, len);
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);
return ptr ? &ptr->entry : NULL;
@@ -401,11 +337,13 @@ void __init tomoyo_realpath_init(void)
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_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. */
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-28 15:03:55 +0000