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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 D685AC43461 for ; Sun, 13 Sep 2020 20:29:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6997A221EB for ; Sun, 13 Sep 2020 20:29:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="GASWo7w8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725968AbgIMU3Q (ORCPT ); Sun, 13 Sep 2020 16:29:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725940AbgIMU3P (ORCPT ); Sun, 13 Sep 2020 16:29:15 -0400 Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 597D0C06174A for ; Sun, 13 Sep 2020 13:29:14 -0700 (PDT) Received: by mail-lj1-x243.google.com with SMTP id c2so16810002ljj.12 for ; Sun, 13 Sep 2020 13:29:14 -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; bh=3lHDoU/H9XzG7I14VS2g4WO/mVOjgOVFse/bjqwpgGU=; b=GASWo7w8jjpUAVHSAIf21CdzDUKCXRV35W1cajLaalGsAZm1e0IAr9uVt42g+O0v9u WbHvgGaZDR7KIeXlnFi2u+n0uzRdSiTfSU/wUdkNAgXQfrLqRJmbFHi6ybdYFkStx6GE IfR/gUE7fNOc5/UdiCFrWXypsjIvB/YlPubFAisfu6oRUjK9HywKUIybZJWnQ3wrLOtT oABZt1Btme/VOTXjCAHwcMZxKK4j4rCfLo3SItwZYxWZ8EdiNvB13o0r+HrHf8+hQ+8h xm2SOSnaF6OnGJIm1jJcVohdBYP1HvpfsVQ3NIwXR3xhIwTqSx3oCFzuLIH/2VD6FHdX IK8A== 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; bh=3lHDoU/H9XzG7I14VS2g4WO/mVOjgOVFse/bjqwpgGU=; b=ReXdO23X5EMR5J5R8/9SACbGfvfdoJquMZUIyz4pL6cgEid+/cvD86o73w+8IpuxGT fIMSIfqthzbKyyrNUjuNo0MRT4GxBNQ8TLhtbc3W7GCBK/2bZ19C+DXNwqlkYyCE9pVb ndW+rR9dRzak2xgm3y8IVj7Hm+9gXqSwc/kSuA6tgoAfrgyC5wFXTPf6akk+ukwHJDoC VpvX2LgNMPBNK59lqeiwK6hshsKuBoARK2q2hNXiNmairiWaKp9k4xmj9rB366GjbWLL pU5TWam0ZcQ8tWO41YIZMCSgZgctXMAUDUsAW4loFxZSIA4qoh/zxsNE6Y4epph8hNUw hBjw== X-Gm-Message-State: AOAM5303bjjwrqEXA85sh1noNytyPQOdlWWgPC8NDfTQU9yW2jm/RWf2 i1O/+YoGeA0jD6IX1D54l0ppSA== X-Google-Smtp-Source: ABdhPJzMJku7nZ/BR0wpi72U8GQD1Sk0KiUEt2zWwei5XG7UX8s1R1FXtKJRrGeeGndblgi43ED84g== X-Received: by 2002:a2e:9948:: with SMTP id r8mr3907576ljj.126.1600028951763; Sun, 13 Sep 2020 13:29:11 -0700 (PDT) Received: from jade (h-249-223.A175.priv.bahnhof.se. [98.128.249.223]) by smtp.gmail.com with ESMTPSA id t15sm3416763ljg.139.2020.09.13.13.29.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 13 Sep 2020 13:29:10 -0700 (PDT) Date: Sun, 13 Sep 2020 22:29:09 +0200 From: Jens Wiklander To: Souptick Joarder Cc: op-tee@lists.trustedfirmware.org, linux-kernel@vger.kernel.org, John Hubbard Subject: Re: [PATCH] tee/tee_shm.c: Fix error handling path Message-ID: <20200913202909.GA1018725@jade> References: <1599972131-31770-1-git-send-email-jrdr.linux@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1599972131-31770-1-git-send-email-jrdr.linux@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 13, 2020 at 10:12:11AM +0530, Souptick Joarder wrote: > When shm->num_pages <= 0, we should avoid calling > release_registered_pages() in error handling path. What are we fixing? > > Signed-off-by: Souptick Joarder > Cc: John Hubbard > --- > drivers/tee/tee_shm.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c > index 00472f5..e517d9f 100644 > --- a/drivers/tee/tee_shm.c > +++ b/drivers/tee/tee_shm.c > @@ -260,8 +260,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, > rc = get_kernel_pages(kiov, num_pages, 0, shm->pages); > kfree(kiov); > } > - if (rc > 0) > - shm->num_pages = rc; > + shm->num_pages = rc; Why not avoiding assigning invalid values to shm->num_pages? By the way, shm->num_pages is a size_t. > if (rc != num_pages) { > if (rc >= 0) > rc = -ENOMEM; > @@ -309,7 +308,9 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, > idr_remove(&teedev->idr, shm->id); > mutex_unlock(&teedev->mutex); > } > - release_registered_pages(shm); > + if (shm->pages && (shm->num_pages > 0)) > + release_registered_pages(shm); > + With this we'll leak if shm->pages has been assigned something. > } > kfree(shm); > teedev_ctx_put(ctx); > -- > 1.9.1 > Thanks, Jens