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Commit 2354d08f authored by Julia Lawall's avatar Julia Lawall Committed by Chris Mason
Browse files

Btrfs: use memdup_user helpers 

Use memdup_user when user data is immediately copied into the
allocated region.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/

)

// <smpl>
@@
expression from,to,size,flag;
position p;
identifier l1,l2;
@@

-  to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+  to = memdup_user(from,size);
   if (
-      to==NULL
+      IS_ERR(to)
                 || ...) {
   <+... when != goto l1;
-  -ENOMEM
+  PTR_ERR(to)
   ...+>
   }
-  if (copy_from_user(to, from, size) != 0) {
-    <+... when != goto l2;
-    -EFAULT
-    ...+>
-  }
// </smpl>

Signed-off-by: default avatarJulia Lawall <julia@diku.dk>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 18e503d6

fs/btrfs/ioctl.c

+6 −14
Original line number Diff line number Diff line
@@ -1073,14 +1073,10 @@ static noinline int btrfs_ioctl_tree_search(struct file *file, 
	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	args = kmalloc(sizeof(*args), GFP_KERNEL);

	if (!args)

		return -ENOMEM;

	args = memdup_user(argp, sizeof(*args));

	if (IS_ERR(args))

		return PTR_ERR(args);



	if (copy_from_user(args, argp, sizeof(*args))) {

		kfree(args);

		return -EFAULT;

	}

	inode = fdentry(file)->d_inode;

	ret = search_ioctl(inode, args);

	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
@@ -1188,14 +1184,10 @@ static noinline int btrfs_ioctl_ino_lookup(struct file *file, 
	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	args = kmalloc(sizeof(*args), GFP_KERNEL);

	if (!args)

		return -ENOMEM;

	args = memdup_user(argp, sizeof(*args));

	if (IS_ERR(args))

		return PTR_ERR(args);



	if (copy_from_user(args, argp, sizeof(*args))) {

		kfree(args);

		return -EFAULT;

	}

	inode = fdentry(file)->d_inode;



	if (args->treeid == 0)