diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 88fefa68c516..a965df4b54f5 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -602,9 +602,26 @@ static ssize_t map_write(struct file *file, const char __user *buf, struct uid_gid_map new_map; unsigned idx; struct uid_gid_extent *extent = NULL; - unsigned long page = 0; + unsigned long page; char *kbuf, *pos, *next_line; - ssize_t ret = -EINVAL; + ssize_t ret; + + /* Only allow < page size writes at the beginning of the file */ + if ((*ppos != 0) || (count >= PAGE_SIZE)) + return -EINVAL; + + /* Get a buffer */ + page = __get_free_page(GFP_TEMPORARY); + kbuf = (char *) page; + if (!page) + return -ENOMEM; + + /* Slurp in the user data */ + if (copy_from_user(kbuf, buf, count)) { + free_page(page); + return -EFAULT; + } + kbuf[count] = '\0'; /* * The userns_state_mutex serializes all writes to any given map. @@ -638,24 +655,6 @@ static ssize_t map_write(struct file *file, const char __user *buf, if (cap_valid(cap_setid) && !file_ns_capable(file, ns, CAP_SYS_ADMIN)) goto out; - /* Get a buffer */ - ret = -ENOMEM; - page = __get_free_page(GFP_TEMPORARY); - kbuf = (char *) page; - if (!page) - goto out; - - /* Only allow < page size writes at the beginning of the file */ - ret = -EINVAL; - if ((*ppos != 0) || (count >= PAGE_SIZE)) - goto out; - - /* Slurp in the user data */ - ret = -EFAULT; - if (copy_from_user(kbuf, buf, count)) - goto out; - kbuf[count] = '\0'; - /* Parse the user data */ ret = -EINVAL; pos = kbuf;