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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
  VM/Security: add security hook to do_brk
  Security: round mmap hint address above mmap_min_addr
  security: protect from stack expantion into low vm addresses
  Security: allow capable check to permit mmap or low vm space
  SELinux: detect dead booleans
  SELinux: do not clear f_op when removing entries
Linus Torvalds 17 years ago
parent
commit
ad658cec23
5 changed files with 57 additions and 40 deletions
  1. 16 0
      include/linux/mm.h
  2. 9 2
      mm/mmap.c
  3. 3 0
      mm/nommu.c
  4. 1 1
      security/dummy.c
  5. 28 37
      security/selinux/selinuxfs.c

+ 16 - 0
include/linux/mm.h

@@ -12,6 +12,7 @@
 #include <linux/prio_tree.h>
 #include <linux/debug_locks.h>
 #include <linux/mm_types.h>
+#include <linux/security.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -512,6 +513,21 @@ static inline void set_page_links(struct page *page, enum zone_type zone,
 	set_page_section(page, pfn_to_section_nr(pfn));
 }
 
+/*
+ * If a hint addr is less than mmap_min_addr change hint to be as
+ * low as possible but still greater than mmap_min_addr
+ */
+static inline unsigned long round_hint_to_min(unsigned long hint)
+{
+#ifdef CONFIG_SECURITY
+	hint &= PAGE_MASK;
+	if (((void *)hint != NULL) &&
+	    (hint < mmap_min_addr))
+		return PAGE_ALIGN(mmap_min_addr);
+#endif
+	return hint;
+}
+
 /*
  * Some inline functions in vmstat.h depend on page_zone()
  */

+ 9 - 2
mm/mmap.c

@@ -912,6 +912,9 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
 	if (!len)
 		return -EINVAL;
 
+	if (!(flags & MAP_FIXED))
+		addr = round_hint_to_min(addr);
+
 	error = arch_mmap_check(addr, len, flags);
 	if (error)
 		return error;
@@ -1615,6 +1618,12 @@ static inline int expand_downwards(struct vm_area_struct *vma,
 	 */
 	if (unlikely(anon_vma_prepare(vma)))
 		return -ENOMEM;
+
+	address &= PAGE_MASK;
+	error = security_file_mmap(0, 0, 0, 0, address, 1);
+	if (error)
+		return error;
+
 	anon_vma_lock(vma);
 
 	/*
@@ -1622,8 +1631,6 @@ static inline int expand_downwards(struct vm_area_struct *vma,
 	 * is required to hold the mmap_sem in read mode.  We need the
 	 * anon_vma lock to serialize against concurrent expand_stacks.
 	 */
-	address &= PAGE_MASK;
-	error = 0;
 
 	/* Somebody else might have raced and expanded it already */
 	if (address < vma->vm_start) {

+ 3 - 0
mm/nommu.c

@@ -829,6 +829,9 @@ unsigned long do_mmap_pgoff(struct file *file,
 	void *result;
 	int ret;
 
+	if (!(flags & MAP_FIXED))
+		addr = round_hint_to_min(addr);
+
 	/* decide whether we should attempt the mapping, and if so what sort of
 	 * mapping */
 	ret = validate_mmap_request(file, addr, len, prot, flags, pgoff,

+ 1 - 1
security/dummy.c

@@ -426,7 +426,7 @@ static int dummy_file_mmap (struct file *file, unsigned long reqprot,
 			    unsigned long addr,
 			    unsigned long addr_only)
 {
-	if (addr < mmap_min_addr)
+	if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO))
 		return -EACCES;
 	return 0;
 }

+ 28 - 37
security/selinux/selinuxfs.c

@@ -65,6 +65,7 @@ static DEFINE_MUTEX(sel_mutex);
 /* global data for booleans */
 static struct dentry *bool_dir = NULL;
 static int bool_num = 0;
+static char **bool_pending_names;
 static int *bool_pending_values = NULL;
 
 /* global data for classes */
@@ -832,15 +833,16 @@ static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 	ssize_t length;
 	ssize_t ret;
 	int cur_enforcing;
-	struct inode *inode;
+	struct inode *inode = filep->f_path.dentry->d_inode;
+	unsigned index = inode->i_ino & SEL_INO_MASK;
+	const char *name = filep->f_path.dentry->d_name.name;
 
 	mutex_lock(&sel_mutex);
 
-	ret = -EFAULT;
-
-	/* check to see if this file has been deleted */
-	if (!filep->f_op)
+	if (index >= bool_num || strcmp(name, bool_pending_names[index])) {
+		ret = -EINVAL;
 		goto out;
+	}
 
 	if (count > PAGE_SIZE) {
 		ret = -EINVAL;
@@ -851,15 +853,13 @@ static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 		goto out;
 	}
 
-	inode = filep->f_path.dentry->d_inode;
-	cur_enforcing = security_get_bool_value(inode->i_ino&SEL_INO_MASK);
+	cur_enforcing = security_get_bool_value(index);
 	if (cur_enforcing < 0) {
 		ret = cur_enforcing;
 		goto out;
 	}
-
 	length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
-			  bool_pending_values[inode->i_ino&SEL_INO_MASK]);
+			  bool_pending_values[index]);
 	ret = simple_read_from_buffer(buf, count, ppos, page, length);
 out:
 	mutex_unlock(&sel_mutex);
@@ -872,9 +872,11 @@ static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 			      size_t count, loff_t *ppos)
 {
 	char *page = NULL;
-	ssize_t length = -EFAULT;
+	ssize_t length;
 	int new_value;
-	struct inode *inode;
+	struct inode *inode = filep->f_path.dentry->d_inode;
+	unsigned index = inode->i_ino & SEL_INO_MASK;
+	const char *name = filep->f_path.dentry->d_name.name;
 
 	mutex_lock(&sel_mutex);
 
@@ -882,16 +884,19 @@ static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 	if (length)
 		goto out;
 
-	/* check to see if this file has been deleted */
-	if (!filep->f_op)
+	if (index >= bool_num || strcmp(name, bool_pending_names[index])) {
+		length = -EINVAL;
 		goto out;
+	}
 
 	if (count >= PAGE_SIZE) {
 		length = -ENOMEM;
 		goto out;
 	}
+
 	if (*ppos != 0) {
 		/* No partial writes. */
+		length = -EINVAL;
 		goto out;
 	}
 	page = (char*)get_zeroed_page(GFP_KERNEL);
@@ -900,6 +905,7 @@ static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 		goto out;
 	}
 
+	length = -EFAULT;
 	if (copy_from_user(page, buf, count))
 		goto out;
 
@@ -910,8 +916,7 @@ static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 	if (new_value)
 		new_value = 1;
 
-	inode = filep->f_path.dentry->d_inode;
-	bool_pending_values[inode->i_ino&SEL_INO_MASK] = new_value;
+	bool_pending_values[index] = new_value;
 	length = count;
 
 out:
@@ -931,7 +936,7 @@ static ssize_t sel_commit_bools_write(struct file *filep,
 				      size_t count, loff_t *ppos)
 {
 	char *page = NULL;
-	ssize_t length = -EFAULT;
+	ssize_t length;
 	int new_value;
 
 	mutex_lock(&sel_mutex);
@@ -940,10 +945,6 @@ static ssize_t sel_commit_bools_write(struct file *filep,
 	if (length)
 		goto out;
 
-	/* check to see if this file has been deleted */
-	if (!filep->f_op)
-		goto out;
-
 	if (count >= PAGE_SIZE) {
 		length = -ENOMEM;
 		goto out;
@@ -958,6 +959,7 @@ static ssize_t sel_commit_bools_write(struct file *filep,
 		goto out;
 	}
 
+	length = -EFAULT;
 	if (copy_from_user(page, buf, count))
 		goto out;
 
@@ -982,11 +984,9 @@ static const struct file_operations sel_commit_bools_ops = {
 	.write          = sel_commit_bools_write,
 };
 
-/* partial revoke() from fs/proc/generic.c proc_kill_inodes */
 static void sel_remove_entries(struct dentry *de)
 {
-	struct list_head *p, *node;
-	struct super_block *sb = de->d_sb;
+	struct list_head *node;
 
 	spin_lock(&dcache_lock);
 	node = de->d_subdirs.next;
@@ -1006,18 +1006,6 @@ static void sel_remove_entries(struct dentry *de)
 	}
 
 	spin_unlock(&dcache_lock);
-
-	file_list_lock();
-	list_for_each(p, &sb->s_files) {
-		struct file * filp = list_entry(p, struct file, f_u.fu_list);
-		struct dentry * dentry = filp->f_path.dentry;
-
-		if (dentry->d_parent != de) {
-			continue;
-		}
-		filp->f_op = NULL;
-	}
-	file_list_unlock();
 }
 
 #define BOOL_DIR_NAME "booleans"
@@ -1036,7 +1024,9 @@ static int sel_make_bools(void)
 	u32 sid;
 
 	/* remove any existing files */
+	kfree(bool_pending_names);
 	kfree(bool_pending_values);
+	bool_pending_names = NULL;
 	bool_pending_values = NULL;
 
 	sel_remove_entries(dir);
@@ -1078,16 +1068,17 @@ static int sel_make_bools(void)
 		d_add(dentry, inode);
 	}
 	bool_num = num;
+	bool_pending_names = names;
 	bool_pending_values = values;
 out:
 	free_page((unsigned long)page);
+	return ret;
+err:
 	if (names) {
 		for (i = 0; i < num; i++)
 			kfree(names[i]);
 		kfree(names);
 	}
-	return ret;
-err:
 	kfree(values);
 	sel_remove_entries(dir);
 	ret = -ENOMEM;