Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760731AbaGDWlf (ORCPT ); Fri, 4 Jul 2014 18:41:35 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57471 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031206AbaGDWVL (ORCPT ); Fri, 4 Jul 2014 18:21:11 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yann Droneaud , Roland Dreier Subject: [PATCH 3.14 23/59] IB/mlx5: add missing padding at end of struct mlx5_ib_create_srq Date: Fri, 4 Jul 2014 15:19:12 -0700 Message-Id: <20140704221540.653367967@linuxfoundation.org> X-Mailer: git-send-email 2.0.1 In-Reply-To: <20140704221539.544876024@linuxfoundation.org> References: <20140704221539.544876024@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yann Droneaud commit 43bc889380c2ad9aa230eccc03a15cc52cf710d4 upstream. The i386 ABI disagrees with most other ABIs regarding alignment of data type larger than 4 bytes: on most ABIs a padding must be added at end of the structures, while it is not required on i386. So for most ABIs struct mlx5_ib_create_srq gets implicitly padded to be aligned on a 8 bytes multiple, while for i386, such padding is not added. Tool pahole could be used to find such implicit padding: $ pahole --anon_include \ --nested_anon_include \ --recursive \ --class_name mlx5_ib_create_srq \ drivers/infiniband/hw/mlx5/mlx5_ib.o Then, structure layout can be compared between i386 and x86_64: # +++ obj-i386/drivers/infiniband/hw/mlx5/mlx5_ib.o.pahole.txt 2014-03-28 11:43:07.386413682 +0100 # --- obj-x86_64/drivers/infiniband/hw/mlx5/mlx5_ib.o.pahole.txt 2014-03-27 13:06:17.788472721 +0100 # @@ -69,7 +68,6 @@ struct mlx5_ib_create_srq { # __u64 db_addr; /* 8 8 */ # __u32 flags; /* 16 4 */ # # - /* size: 20, cachelines: 1, members: 3 */ # - /* last cacheline: 20 bytes */ # + /* size: 24, cachelines: 1, members: 3 */ # + /* padding: 4 */ # + /* last cacheline: 24 bytes */ # }; ABI disagreement will make an x86_64 kernel try to read past the buffer provided by an i386 binary. When boundary check will be implemented, the x86_64 kernel will refuse to read past the i386 userspace provided buffer and the uverb will fail. Anyway, if the structure lay in memory on a page boundary and next page is not mapped, ib_copy_from_udata() will fail and the uverb will fail. This patch makes create_srq_user() takes care of the input data size to handle the case where no padding was provided. This way, x86_64 kernel will be able to handle struct mlx5_ib_create_srq as sent by unpatched and patched i386 libmlx5. Link: http://marc.info/?i=cover.1399309513.git.ydroneaud@opteya.com Fixes: e126ba97dba9e ("mlx5: Add driver for Mellanox Connect-IB adapter") Signed-off-by: Yann Droneaud Signed-off-by: Roland Dreier Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/hw/mlx5/srq.c | 14 +++++++++++++- drivers/infiniband/hw/mlx5/user.h | 1 + 2 files changed, 14 insertions(+), 1 deletion(-) --- a/drivers/infiniband/hw/mlx5/srq.c +++ b/drivers/infiniband/hw/mlx5/srq.c @@ -35,6 +35,7 @@ #include #include #include +#include #include "mlx5_ib.h" #include "user.h" @@ -78,16 +79,27 @@ static int create_srq_user(struct ib_pd { struct mlx5_ib_dev *dev = to_mdev(pd->device); struct mlx5_ib_create_srq ucmd; + size_t ucmdlen; int err; int npages; int page_shift; int ncont; u32 offset; - if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd))) { + ucmdlen = + (udata->inlen - sizeof(struct ib_uverbs_cmd_hdr) < + sizeof(ucmd)) ? (sizeof(ucmd) - + sizeof(ucmd.reserved)) : sizeof(ucmd); + + if (ib_copy_from_udata(&ucmd, udata, ucmdlen)) { mlx5_ib_dbg(dev, "failed copy udata\n"); return -EFAULT; } + + if (ucmdlen == sizeof(ucmd) && + ucmd.reserved != 0) + return -EINVAL; + srq->wq_sig = !!(ucmd.flags & MLX5_SRQ_FLAG_SIGNATURE); srq->umem = ib_umem_get(pd->uobject->context, ucmd.buf_addr, buf_size, --- a/drivers/infiniband/hw/mlx5/user.h +++ b/drivers/infiniband/hw/mlx5/user.h @@ -110,6 +110,7 @@ struct mlx5_ib_create_srq { __u64 buf_addr; __u64 db_addr; __u32 flags; + __u32 reserved; /* explicit padding (optional on i386) */ }; struct mlx5_ib_create_srq_resp { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/