kernel/*: switch to memdup_user_nul()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 88fefa6..9bafc21 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -602,8 +602,7 @@
struct uid_gid_map new_map;
unsigned idx;
struct uid_gid_extent *extent = NULL;
- unsigned long page = 0;
- char *kbuf, *pos, *next_line;
+ char *kbuf = NULL, *pos, *next_line;
ssize_t ret = -EINVAL;
/*
@@ -638,23 +637,18 @@
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))
+ kbuf = memdup_user_nul(buf, count);
+ if (IS_ERR(kbuf)) {
+ ret = PTR_ERR(kbuf);
+ kbuf = NULL;
goto out;
- kbuf[count] = '\0';
+ }
/* Parse the user data */
ret = -EINVAL;
@@ -756,8 +750,7 @@
ret = count;
out:
mutex_unlock(&userns_state_mutex);
- if (page)
- free_page(page);
+ kfree(kbuf);
return ret;
}
