From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH v16 04/16] mm: untag user pointers in do_pages_move Date: Fri, 7 Jun 2019 20:49:05 -0700 Message-ID: <201906072049.C71D545@keescook> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Andrey Konovalov Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, Catalin Marinas , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Yishai Hadas , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander List-Id: linux-rdma@vger.kernel.org On Mon, Jun 03, 2019 at 06:55:06PM +0200, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > do_pages_move() is used in the implementation of the move_pages syscall. > > Untag user pointers in this function. > > Reviewed-by: Catalin Marinas > Signed-off-by: Andrey Konovalov Reviewed-by: Kees Cook -Kees > --- > mm/migrate.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/migrate.c b/mm/migrate.c > index f2ecc2855a12..3930bb6fa656 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1617,6 +1617,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, > if (get_user(node, nodes + i)) > goto out_flush; > addr = (unsigned long)p; > + addr = untagged_addr(addr); > > err = -ENODEV; > if (node < 0 || node >= MAX_NUMNODES) > -- > 2.22.0.rc1.311.g5d7573a151-goog > -- Kees Cook