[PATCH 4.4 13/97] getname_kernel() needs to make sure that ->name != ->iname in long case

From: Greg Kroah-Hartman
Date: Sun Apr 22 2018 - 10:49:38 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit 30ce4d1903e1d8a7ccd110860a5eef3c638ed8be upstream.

missed it in "kill struct filename.separate" several years ago.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/namei.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/namei.c
+++ b/fs/namei.c
@@ -219,9 +219,10 @@ getname_kernel(const char * filename)
if (len <= EMBEDDED_NAME_MAX) {
result->name = (char *)result->iname;
} else if (len <= PATH_MAX) {
+ const size_t size = offsetof(struct filename, iname[1]);
struct filename *tmp;

- tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
+ tmp = kmalloc(size, GFP_KERNEL);
if (unlikely(!tmp)) {
__putname(result);
return ERR_PTR(-ENOMEM);