Re: [PATCH] ipc: shm: fix information leak to userland

[Dan Rosenberg <drosenberg@vsecurity.com>]

This one already got taken care of by Kees Cook:

http://lkml.org/lkml/2010/10/6/486

Thanks,
Dan

> Structure shmid_ds is copied to userland with shm_unused{,2,3}
> fields unitialized.  It leads to leaking of contents of kernel stack
> memory.
> Cc: stable@kernel.org
> Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
> Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
> ---
>  Compile tested.
>  ipc/shm.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> diff --git a/ipc/shm.c b/ipc/shm.c
> index fd658a1..7d3bb22 100644
> --- a/ipc/shm.c
> +++ b/ipc/shm.c
> @@ -479,6 +479,7 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_
>  	    {
>  		struct shmid_ds out;
>  
> +		memset(&out, 0, sizeof(out));
>  		ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
>  		out.shm_segsz	= in->shm_segsz;
>  		out.shm_atime	= in->shm_atime;