From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967089AbdEWJah (ORCPT ); Tue, 23 May 2017 05:30:37 -0400 Received: from stargate.chelsio.com ([12.32.117.8]:32746 "EHLO stargate.chelsio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759318AbdEWJaf (ORCPT ); Tue, 23 May 2017 05:30:35 -0400 Date: Tue, 23 May 2017 15:00:26 +0530 From: Varun Prakash To: Kees Cook Cc: LKML , "James E.J. Bottomley" , "Martin K. Petersen" , "linux-scsi@vger.kernel.org" , Daniel Micay Subject: Re: [PATCH] csiostor: Avoid content leaks and casts Message-ID: <20170523093024.GA1667@chelsio.com> References: <20170509223444.GA51314@beast> <20170522150544.GA1677@chelsio.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 22, 2017 at 09:29:41AM -0700, Kees Cook wrote: > On Mon, May 22, 2017 at 8:05 AM, Varun Prakash wrote: > > On Tue, May 09, 2017 at 03:34:44PM -0700, Kees Cook wrote: > >> When copying attributes, the len argument was padded out and the resulting > >> memcpy() would copy beyond the end of the source buffer. Avoid this, > >> and use size_t for val_len to avoid all the casts. Similarly, avoid source > >> buffer casts and use void *. > >> > >> Additionally enforces val_len can be represented by u16 and that > >> the DMA buffer was not overflowed. Fixes the size of mfa, which is not > >> FC_FDMI_PORT_ATTR_MAXFRAMESIZE_LEN (but it will be padded up to 4). This > >> was noticed by the future CONFIG_FORTIFY_SOURCE checks. > >> > >> Cc: Daniel Micay > >> Signed-off-by: Kees Cook > >> --- > >> drivers/scsi/csiostor/csio_lnode.c | 43 +++++++++++++++++++++++--------------- > >> 1 file changed, 26 insertions(+), 17 deletions(-) > >> > >> diff --git a/drivers/scsi/csiostor/csio_lnode.c b/drivers/scsi/csiostor/csio_lnode.c > >> index c00b2ff72b55..be5ee2d37815 100644 > >> --- a/drivers/scsi/csiostor/csio_lnode.c > >> +++ b/drivers/scsi/csiostor/csio_lnode.c > >> @@ -238,14 +238,23 @@ csio_osname(uint8_t *buf, size_t buf_len) > >> } > >> > > > > > >> > >> csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_MAXCTPAYLOAD, > >> - (uint8_t *)&maxpayload, > >> - FC_FDMI_HBA_ATTR_MAXCTPAYLOAD_LEN); > >> + &maxpayload, FC_FDMI_HBA_ATTR_MAXCTPAYLOAD_LEN); > >> len = (uint32_t)(pld - (uint8_t *)cmd); > >> numattrs++; > >> attrib_blk->numattrs = htonl(numattrs); > >> @@ -1794,6 +1801,8 @@ csio_ln_mgmt_submit_req(struct csio_ioreq *io_req, > >> struct csio_mgmtm *mgmtm = csio_hw_to_mgmtm(hw); > >> int rv; > >> > >> + BUG_ON(pld_len > pld->len); > >> + > > > > I think WARN_ON() is better than BUG_ON() in this case > > > > if (WARN_ON(pld_len > pld->len)) > > return -EINVAL; > > > >> io_req->io_cbfn = io_cbfn; /* Upper layer callback handler */ > >> io_req->fw_handle = (uintptr_t) (io_req); > >> io_req->eq_idx = mgmtm->eq_idx; > > I chose BUG_ON here because the damage has already been done. If this > assertion is hit, the heap buffers have already been overrun. This > isn't a state we should only warn about... > Ok. Acked-by: Varun Prakash