[GIT PULL] Audit fixes for 3.19 #2

[Al Viro]

On Thu, Jan 01, 2015 at 12:01:49AM +0000, Al Viro wrote:

> Umm...  How about just adding a function that would be used instead of
> all those
>         struct filename filename = { .name = name };
> and created an object that would be destroyed later by putname()?

... such as getname_kernel(), actually.  There are 5 places like that:
fs/exec.c:open_exec(), fs/namei.c:do_path_lookup(),
fs/namei.c:kern_path_mountpoint(), fs/namei.c:do_file_open_root(),
fs/open.c:filp_open().  Said that, I'm not sure that no call chains
allow names just under PATH_MAX, so getname_kernel() might need to be
taught to handle those.