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 X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B706C49EAB for ; Thu, 24 Jun 2021 14:32:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76CBB613F2 for ; Thu, 24 Jun 2021 14:32:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232108AbhFXOfN (ORCPT ); Thu, 24 Jun 2021 10:35:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232067AbhFXOfM (ORCPT ); Thu, 24 Jun 2021 10:35:12 -0400 Received: from mail-pj1-x1036.google.com (mail-pj1-x1036.google.com [IPv6:2607:f8b0:4864:20::1036]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53B91C061756 for ; Thu, 24 Jun 2021 07:32:53 -0700 (PDT) Received: by mail-pj1-x1036.google.com with SMTP id k5so3602108pjj.1 for ; Thu, 24 Jun 2021 07:32:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=mZ5KlgV4skhOj5gTvR4vLXaoA/Zt4yAkmCPckN2oA9U=; b=jSQ97apMr7ov5WqeLGxiO0pXS+bMBS/GvSn2PwaAOYrog2uDjJ1I0JAkOpnnyT5hkc PY1nhNURjmvNV9ELhnJGdomlVexunLflJXRTpPQ2s3i31sB2Ljg9p2sxShRAsgXmz1Ft yTKgHm907KXUCTa4XsGs79ehN/zcH4TZVpqvwtb4sK4MMpzDfmK3MBo54Ub8TDE5n1ga o4oKyDy50Wj084IPcuOTmTHXG/2cVaiuSfPYztfF7a2X/YSGFTlzPXKA2cxM5A7auD0r I8YsG44oi35bfquoFtt5KnUBLd9AWJ54bRNzyaDYZoMIKh1ohttigaJqJaiPe2ElHaFA ybmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=mZ5KlgV4skhOj5gTvR4vLXaoA/Zt4yAkmCPckN2oA9U=; b=DzxCZghB6imcWE+HVTa/UEAts6PRqCS3MzdUlms0r3gT7AmZyRH9ORLGeJKD5uZL26 N8lZ+lbKGjb3A0BI66fTO/xRCh0EU2TnYSgS7w/Ll+T8OyS2pcGDmeW0db2ZcoVPCa6t 8F0lQzXxq4tmQYDOfMsiYqPdXbOL/hG7f/Zcc5hkANGUjmfjbQOk5CJ6v5uWpp1xtG5j btY/Gz3gY7ulRZKptBeaNbfwO/1EuctfQTuMBQln+t3FLyCBixxIJ5cPU3wi+oSn5p10 XgweKyJmK3L1gJ2sT56itTWb770LgAQs+NIJwcKexH5n+h9n8CEcgk51V80aH7jvFgcV xtqw== X-Gm-Message-State: AOAM530L6UxxOBK/TuyryYqxAihlFOGMewlPrgQynVXqG3kfBYxdm3Sp 7wEFQA2+LjznY2xF41+H9jTd X-Google-Smtp-Source: ABdhPJzPu3fz/B7ls96dBWmzLTmn8AkR+IlhW59m8sA93c4r/yWjj3nS79DYOZmEyQfzzCLwozDi7A== X-Received: by 2002:a17:90a:7801:: with SMTP id w1mr5700676pjk.179.1624545172726; Thu, 24 Jun 2021 07:32:52 -0700 (PDT) Received: from workstation ([120.138.12.173]) by smtp.gmail.com with ESMTPSA id j13sm3166608pfh.145.2021.06.24.07.32.50 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 24 Jun 2021 07:32:52 -0700 (PDT) Date: Thu, 24 Jun 2021 20:02:48 +0530 From: Manivannan Sadhasivam To: Greg KH Cc: hemantk@codeaurora.org, bbhatt@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, loic.poulain@linaro.org, stable@vger.kernel.org, Jeffrey Hugo Subject: Re: [PATCH 1/8] bus: mhi: core: Validate channel ID when processing command completions Message-ID: <20210624143248.GC6108@workstation> References: <20210621161616.77524-1-manivannan.sadhasivam@linaro.org> <20210621161616.77524-2-manivannan.sadhasivam@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 24, 2021 at 03:50:45PM +0200, Greg KH wrote: > On Mon, Jun 21, 2021 at 09:46:09PM +0530, Manivannan Sadhasivam wrote: > > From: Bhaumik Bhatt > > > > MHI reads the channel ID from the event ring element sent by the > > device which can be any value between 0 and 255. In order to > > prevent any out of bound accesses, add a check against the maximum > > number of channels supported by the controller and those channels > > not configured yet so as to skip processing of that event ring > > element. > > > > Cc: stable@vger.kernel.org > > Fixes: 1d3173a3bae7 ("bus: mhi: core: Add support for processing events from client device") > > Signed-off-by: Bhaumik Bhatt > > Reviewed-by: Hemant Kumar > > Reviewed-by: Manivannan Sadhasivam > > Reviewed-by: Jeffrey Hugo > > Link: https://lore.kernel.org/r/1619481538-4435-1-git-send-email-bbhatt@codeaurora.org > > Signed-off-by: Manivannan Sadhasivam > > --- > > drivers/bus/mhi/core/main.c | 15 ++++++++++----- > > 1 file changed, 10 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c > > index 22acde118bc3..ed07421c4870 100644 > > --- a/drivers/bus/mhi/core/main.c > > +++ b/drivers/bus/mhi/core/main.c > > @@ -773,11 +773,16 @@ static void mhi_process_cmd_completion(struct mhi_controller *mhi_cntrl, > > cmd_pkt = mhi_to_virtual(mhi_ring, ptr); > > > > chan = MHI_TRE_GET_CMD_CHID(cmd_pkt); > > - mhi_chan = &mhi_cntrl->mhi_chan[chan]; > > - write_lock_bh(&mhi_chan->lock); > > - mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre); > > - complete(&mhi_chan->completion); > > - write_unlock_bh(&mhi_chan->lock); > > + WARN_ON(chan >= mhi_cntrl->max_chan); > > What can ever trigger this WARN_ON()? Do you mean to reboot a machine > if panic-on-warn is set? > > If this can actually happen, then check for it and recover properly, > don't just blindly warn and then keep on going. > We can't do much here other than warning the user and dropping the command. There is no recovery possible because, the device has sent the command completion event on a wrong channel. It can't happen usually unless a malcious device sits on the other end. Thanks, Mani > thanks, > > greg k-h