Userspace can alter the string after the kernel has run strlen_user().
Also: the strlen_user() return value includes the \0, so fix that.
Also: handle EFAULT from strlen_user().
It's unlikely anyone is using this code. Very, very unlikely. If I
remember correctly, CONFIG_HPUX turns this code on, but one would actually
need CONFIG_BINFMT_SOM to load a binary that could cause a problem, and
BINFMT_SOM has had an #error in it for quite some time.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>