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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 ECF26C4320A for ; Thu, 2 Sep 2021 06:06:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD4A760FDC for ; Thu, 2 Sep 2021 06:06:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236762AbhIBGHU (ORCPT ); Thu, 2 Sep 2021 02:07:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230215AbhIBGHS (ORCPT ); Thu, 2 Sep 2021 02:07:18 -0400 Received: from mail-ej1-x62d.google.com (mail-ej1-x62d.google.com [IPv6:2a00:1450:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA649C061575; Wed, 1 Sep 2021 23:06:20 -0700 (PDT) Received: by mail-ej1-x62d.google.com with SMTP id i21so1688076ejd.2; Wed, 01 Sep 2021 23:06:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=whTkJ6zC7O+D+IeTOzd/hrZqqXkNOkHj9zN0Rud1rlU=; b=QByrQJYeYenX851WILof2vh1HOu3BNn5jOF+A5FaXZn2QGhg1jbvFqDtWm5q9AsFak NuQbh/nlGXh+Kn7gg7ZGGfLr32tXSyQQXxvRItHQ/FTWSBRhJZNJJv2oW4/I8xvQ14up 1nmzO8yayF9rNNCSa3MvNqnIUuSjIDiOXvvy9MyNEAN6sg2RW8e3w8pwmdL7Q38QjByg 2xa5wQ/wYwkADgZZ242Xx6ZlqfIwhpTpTkr/gwihWaHkV6NaHomH6zJNVHccy3FWxzcb w+SytK3PE5kK+3dba9ILNoEVaIUS/pZDQUWh+fsXrMC9fnjpEZUTx0lxUJGyK0s/yPC+ GyuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=whTkJ6zC7O+D+IeTOzd/hrZqqXkNOkHj9zN0Rud1rlU=; b=cSbYkXzHfvhI63kZVbI2XDGmUdhANbiHv4mUSjZIywJc3TTDzNwUsJ5CgL2QcopBfX qrnR5ZwPyoDdDBEkVV06vAzX1nJ1CUzc0Jz0ucqkfEfDxD7ieqqEK/IBf/IL373RVA0S Y4HxLsJHIDsF9pvVN1ZleSXpCbiUtmyIE/0yeB9rlNfX1w2D8u+CXu+jSxDd/Dzt0Uky 37IVxuc9MLfvfLJppTyIjuqoFKwPMWCoehT/VQeOy1gi+LQ0jKhvFkuNAt3yR5q/Smnp 27+L84SBVoqGGWzidJM9sU4m6ea1uIwODKCTwpVNAtNHiy0EtTIE08lFZX2VopOzXe6+ 2DCw== X-Gm-Message-State: AOAM5313IzoWG0t+u4W8iVsrYcwqPw7NtcqPMCEh8wg43JmHGh2dnIsR 5c2tH7XNP8tPbbWP/zeVyiNY670b7scnIrhIamLsUEkR7rn7FHQC X-Google-Smtp-Source: ABdhPJwEHZRxfRsnNHsnFH8N+CevlheXR4BPBxMjgPoc8wp1dSZlIGfBjTim029/qcTHMYtX+/UNLC6istu70rdugns= X-Received: by 2002:a17:906:31ca:: with SMTP id f10mr2027189ejf.73.1630562779255; Wed, 01 Sep 2021 23:06:19 -0700 (PDT) MIME-Version: 1.0 References: <20210902060213.1702544-1-mudongliangabcd@gmail.com> In-Reply-To: <20210902060213.1702544-1-mudongliangabcd@gmail.com> From: Dongliang Mu Date: Thu, 2 Sep 2021 14:05:52 +0800 Message-ID: Subject: Re: [PATCH 4.19] fbmem: add margin check to fb_check_caps() To: Bartlomiej Zolnierkiewicz Cc: George Kennedy , syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com, Dan Carpenter , Dhaval Giani , Sasha Levin , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 2, 2021 at 2:02 PM Dongliang Mu wrote: > > [ Upstream commit a49145acfb975d921464b84fe00279f99827d816 ] > > A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting > or yres setting in struct fb_var_screeninfo will result in a > KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as > the margins are being cleared. The margins are cleared in > chunks and if the xres setting or yres setting is a value of > zero upto the chunk size, the failure will occur. > > Add a margin check to validate xres and yres settings. > > Note that, this patch needs special handling to backport it to linux > kernel 4.19, 4.14, 4.9, 4.4. I have tested that, this patch can be applied to the branches: linux-4.19.y/linux-4.14.y/linux-4.9.y/linux-4.4.y. > > Signed-off-by: George Kennedy > Reported-by: syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com > Reviewed-by: Dan Carpenter > Cc: Dhaval Giani > Signed-off-by: Bartlomiej Zolnierkiewicz > Link: https://patchwork.freedesktop.org/patch/msgid/1594149963-13801-1-git-send-email-george.kennedy@oracle.com > Signed-off-by: Sasha Levin > --- > drivers/video/fbdev/core/fbmem.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c > index 84845275dbef..de04c097d67c 100644 > --- a/drivers/video/fbdev/core/fbmem.c > +++ b/drivers/video/fbdev/core/fbmem.c > @@ -991,6 +991,10 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var) > goto done; > } > > + /* bitfill_aligned() assumes that it's at least 8x8 */ > + if (var->xres < 8 || var->yres < 8) > + return -EINVAL; > + > ret = info->fbops->fb_check_var(var, info); > > if (ret) > -- > 2.25.1 >