proc_pid_attr_write(): switch to memdup_user()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-12-24 00:16:30 -05:00
parent 70f6cbb6f9
commit bb646cdb12

View File

@ -2359,7 +2359,7 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file_inode(file);
char *page;
void *page;
ssize_t length;
struct task_struct *task = get_proc_task(inode);
@ -2374,14 +2374,11 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
if (*ppos != 0)
goto out;
length = -ENOMEM;
page = (char*)__get_free_page(GFP_TEMPORARY);
if (!page)
page = memdup_user(buf, count);
if (IS_ERR(page)) {
length = PTR_ERR(page);
goto out;
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out_free;
}
/* Guard against adverse ptrace interaction */
length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
@ -2390,10 +2387,10 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
length = security_setprocattr(task,
(char*)file->f_path.dentry->d_name.name,
(void*)page, count);
page, count);
mutex_unlock(&task->signal->cred_guard_mutex);
out_free:
free_page((unsigned long) page);
kfree(page);
out:
put_task_struct(task);
out_no_task: