patch-2.2.18 linux/mm/swapfile.c

• Lines: 71
• Date: Sun Sep 17 17:51:58 2000
• Orig file: v2.2.17/mm/swapfile.c
• Orig date: Fri Apr 21 12:47:02 2000

diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/mm/swapfile.c linux/mm/swapfile.c
@@ -494,6 +494,7 @@
 	int lock_map_size = PAGE_SIZE;
 	int nr_good_pages = 0;
 	unsigned long tmp_lock_map = 0;
+	int swapfilesize;
 	
 	lock_kernel();
 	if (!capable(CAP_SYS_ADMIN))
@@ -532,27 +533,32 @@
 	error = -EINVAL;
 
 	if (S_ISBLK(swap_dentry->d_inode->i_mode)) {
-		p->swap_device = swap_dentry->d_inode->i_rdev;
-		set_blocksize(p->swap_device, PAGE_SIZE);
+		kdev_t dev = swap_dentry->d_inode->i_rdev;
+
+		p->swap_device = dev;
+		set_blocksize(dev, PAGE_SIZE);
 		
 		filp.f_dentry = swap_dentry;
 		filp.f_mode = 3; /* read write */
 		error = blkdev_open(swap_dentry->d_inode, &filp);
 		if (error)
 			goto bad_swap_2;
-		set_blocksize(p->swap_device, PAGE_SIZE);
+		set_blocksize(dev, PAGE_SIZE);
 		error = -ENODEV;
-		if (!p->swap_device ||
-		    (blk_size[MAJOR(p->swap_device)] &&
-		     !blk_size[MAJOR(p->swap_device)][MINOR(p->swap_device)]))
+		if (!dev || (blk_size[MAJOR(dev)] &&
+			     !blk_size[MAJOR(dev)][MINOR(dev)]))
 			goto bad_swap;
 		error = -EBUSY;
 		for (i = 0 ; i < nr_swapfiles ; i++) {
 			if (i == type)
 				continue;
-			if (p->swap_device == swap_info[i].swap_device)
+			if (dev == swap_info[i].swap_device)
 				goto bad_swap;
 		}
+		swapfilesize = 0;
+		if (blk_size[MAJOR(dev)])
+			swapfilesize = blk_size[MAJOR(dev)][MINOR(dev)]
+				>> (PAGE_SHIFT - 10);
 	} else if (S_ISREG(swap_dentry->d_inode->i_mode)) {
 		error = -EBUSY;
 		for (i = 0 ; i < nr_swapfiles ; i++) {
@@ -561,6 +567,7 @@
 			if (swap_dentry->d_inode == swap_info[i].swap_file->d_inode)
 				goto bad_swap;
 		}
+		swapfilesize = swap_dentry->d_inode->i_size  >> PAGE_SHIFT;
 	} else
 		goto bad_swap;
 
@@ -656,7 +663,13 @@
 		if (error) 
 			goto bad_swap;
 	}
-	
+
+	if (swapfilesize && p->max > swapfilesize) {
+		printk(KERN_WARNING
+		       "Swap area shorter than signature indicates\n");
+		error = -EINVAL;
+		goto bad_swap;
+	}
 	if (!nr_good_pages) {
 		printk(KERN_WARNING "Empty swap-file\n");
 		error = -EINVAL;