From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH v16 14/16] tee, arm64: untag user pointers in tee_shm_register Date: Fri, 7 Jun 2019 21:05:02 -0700 Message-ID: <201906072104.B6A89D8CB@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 06:55:16PM +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. > > tee_shm_register()->optee_shm_unregister()->check_mem_type() uses provided > user pointers for vma lookups (via __check_mem_type()), which can only by > done with untagged pointers. > > Untag user pointers in this function. > > Signed-off-by: Andrey Konovalov "tee: shm: untag user pointers in tee_shm_register" Reviewed-by: Kees Cook -Kees > --- > drivers/tee/tee_shm.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c > index 49fd7312e2aa..96945f4cefb8 100644 > --- a/drivers/tee/tee_shm.c > +++ b/drivers/tee/tee_shm.c > @@ -263,6 +263,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, > shm->teedev = teedev; > shm->ctx = ctx; > shm->id = -1; > + addr = untagged_addr(addr); > start = rounddown(addr, PAGE_SIZE); > shm->offset = addr - start; > shm->size = length; > -- > 2.22.0.rc1.311.g5d7573a151-goog > -- Kees Cook