From: Julia Lawall <julia@diku.dk>
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: Julia Lawall <julia@diku.dk>
---
fs/btrfs/ioctl.c | 20 ++++++--------------
1 file changed, 6 insertions(+), 14 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 97a9783..5301d78 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1096,14 +1096,10 @@ 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)))
@@ -1211,14 +1207,10 @@ 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)