From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C513C4332F for ; Sun, 5 Nov 2023 08:33:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229500AbjKEId1 (ORCPT ); Sun, 5 Nov 2023 03:33:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229455AbjKEId1 (ORCPT ); Sun, 5 Nov 2023 03:33:27 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EE6DD9; Sun, 5 Nov 2023 01:33:24 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD600C433C7; Sun, 5 Nov 2023 08:33:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699173204; bh=DO7rti32qM8aexLDfsJn/f7IKXiyncbiQH0D8eWb7AY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BPkNcDBofM3ig2gdmaHp7oUelf/DCjlyfbX5zZOnCVinCSDsiRH4MdsXOq9KQFHDi NbiEno5Etjh22cdFCaB90JR6ILLN/qZMnRXosqprq2zL4l79yyBv/53niFxyDwmc43 rrd4oh5PFamKyfE3RMn6miwZrR4EeizyQWbO0VECYSPmzCgRRZM8l2smKlo91V9nr9 upC+awhR06ymL6z7HjBVxoIwwwrqLFgwqJYpbYPn384I6nMbeTDr/Q3OTW15Q5Rziu NPSoMONt//KASjSXS1Hhzho2LI72TToftJVi4RcySUcOA9cmJ15KbGpCAs7bgPhvOE M8gGSDlqrGRVQ== Date: Sun, 5 Nov 2023 14:03:16 +0530 From: Manivannan Sadhasivam To: Krishna chaitanya chundru Cc: Manivannan Sadhasivam , mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, quic_vbadigan@quicinc.com, quic_ramkri@quicinc.com, quic_skananth@quicinc.com, quic_parass@quicinc.com, stable@vger.kernel.org Subject: Re: [PATCH v2] bus: mhi: host: Add alignment check for event ring read pointer Message-ID: <20231105083316.GA2508@thinkpad> References: <20231031-alignment_check-v2-1-1441db7c5efd@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20231031-alignment_check-v2-1-1441db7c5efd@quicinc.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Oct 31, 2023 at 03:21:05PM +0530, Krishna chaitanya chundru wrote: > Though we do check the event ring read pointer by "is_valid_ring_ptr" > to make sure it is in the buffer range, but there is another risk the > pointer may be not aligned. Since we are expecting event ring elements > are 128 bits(struct mhi_ring_element) aligned, an unaligned read pointer > could lead to multiple issues like DoS or ring buffer memory corruption. > > So add a alignment check for event ring read pointer. > > Fixes: ec32332df764 ("bus: mhi: core: Sanity check values from remote device before use") > cc: stable@vger.kernel.org > Signed-off-by: Krishna chaitanya chundru Applied to mhi-next! - Mani > --- > Changes in v2: > - Change the modulus operation to bit-wise & operation as suggested by Jeff. > - Link to v1: https://lore.kernel.org/r/20231023-alignment_check-v1-1-2ca5716d5c15@quicinc.com > --- > drivers/bus/mhi/host/main.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c > index 499590437e9b..e765c16a99d1 100644 > --- a/drivers/bus/mhi/host/main.c > +++ b/drivers/bus/mhi/host/main.c > @@ -268,7 +268,8 @@ static void mhi_del_ring_element(struct mhi_controller *mhi_cntrl, > > static bool is_valid_ring_ptr(struct mhi_ring *ring, dma_addr_t addr) > { > - return addr >= ring->iommu_base && addr < ring->iommu_base + ring->len; > + return addr >= ring->iommu_base && addr < ring->iommu_base + ring->len && > + !(addr & (sizeof(struct mhi_ring_element) - 1)); > } > > int mhi_destroy_device(struct device *dev, void *data) > > --- > base-commit: 71e68e182e382e951d6248bccc3c960dcec5a718 > change-id: 20231013-alignment_check-c013f509d24a > > Best regards, > -- > Krishna chaitanya chundru > > -- மணிவண்ணன் சதாசிவம்