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 F1E57C4167B for ; Wed, 1 Nov 2023 05:18:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229784AbjKAFSG (ORCPT ); Wed, 1 Nov 2023 01:18:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229600AbjKAFSG (ORCPT ); Wed, 1 Nov 2023 01:18:06 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11592B9; Tue, 31 Oct 2023 22:18:04 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F24CC433C7; Wed, 1 Nov 2023 05:17:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698815883; bh=DkUg7pfZ4z/iTm73K2U8uyk55cKIRa7vs2uU4EXIrts=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r0Bn4roVOaKKoa+JEyY5SzXkU8sRq4zvNSr9+TIWphrBIJhavBpks65T6UU1OKKsK aucneQ/IhN9A48uJU4nVKfqsJmJQV4VZA4VQBIK3VbM9VVI5kc28oKZ8gTNE9L2Raa qVa033/FJ8zL9eD3o97RKr+YFH4+26P+/ETn5Xh0Ss5zCqDnXg5JYBizoO+Ofc1kmN doveXqAfMDEK7/Apz52hZDEkAHLBqLyVQZ6NpABuGwwIw5XAfc8qmcm/PQxaDW55Ey nW5jroJLaBEQorfE+oUN5WCUX/0Eweg/x9QhEGCiJQ7lyc51zRU9O5RmSxC6hfZZwr PRhm9cREuAotQ== Date: Wed, 1 Nov 2023 10:47:48 +0530 From: Manivannan Sadhasivam To: Krishna chaitanya chundru Cc: 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: <20231101051748.GD2897@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 Reviewed-by: Manivannan Sadhasivam Bjorn gave his R-b tag for v1 and you didn't include it. If you dropped it on purpose, then you should mention it in the "Changes" along with a justification. - 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