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=-15.8 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,USER_AGENT_GIT 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 23747C07E9A for ; Wed, 14 Jul 2021 04:09:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02C0D60698 for ; Wed, 14 Jul 2021 04:09:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230161AbhGNEMY (ORCPT ); Wed, 14 Jul 2021 00:12:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbhGNEMY (ORCPT ); Wed, 14 Jul 2021 00:12:24 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F3AAC0613DD; Tue, 13 Jul 2021 21:09:33 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id j3so858829plx.7; Tue, 13 Jul 2021 21:09:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=dNtQuwwmGDuffyzJJxrC7J0rgzq3v1ZDzE0BZBmT5ME=; b=sxOlB05EOu4kn6zBdjcf/8lnqNeshmDp+JV2COQqQu3eiCOXAlCW2olxWyiux6I+cR m1fQCMhPWt1EJf3XgyTYjmTyqbItav6hVhx49OHEZ/1tiuLt+nG2C1YfW+X/dFO+2y1w kWxr5DUB8320YFJTUu/6OTMiDjYcGoxW/0xsOyX2GPbvaopJhuLL0Wau/Po7AITJgeuy ajetYOHwZWIofp8OCYSqVtWcIWIwJ/yFAMvylIkaFesFCjTCeLuAUkvXckFOx99zitMk 9kh0djrXPHWJSLcJAIae59fRH8vXJ+ZiOtfWy566QkZZG7leZeWM+CUb02iH2qDQ3jTj 0gaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=dNtQuwwmGDuffyzJJxrC7J0rgzq3v1ZDzE0BZBmT5ME=; b=Pv4P7L5Ro2kTZafsR76Q6ANhePMhGH1IHHxKjgQa3rUlxnWvSSHCFGu+DXAv8jY5rg FZub3WF7RiJ2Qo6sMmh2IK5aCzbAzoDWXs865/sR1ICSaMd2b9y/VHMIbFZ7woLtWaV7 C7guc5RdQEsRkrsiGtGJgk883HmsGxaO76G307G1+rw3K6+wANqaR9v3aAhgzk+KIv+h rsDeKsu638b9sXoqEqoQX18BWLHDqnbLpbsza04Xdoa9QNDzwDzuoo4mn6Qjgskw6LRL fPMt6ET+iZ8skEdwuKEgXYkVRqZ5cKxkowgjviEasV2lGj0qU8EE1MHa7CmerfSi1uCN w4TA== X-Gm-Message-State: AOAM532wMCBORvJ2wGTRG4MfNbKAS5Ls2wVZBKvoAKRY+pbDHWeg+XwI AgH8Cp6/eXTSV/BN8PyK7aLU/frvPT+5RaY= X-Google-Smtp-Source: ABdhPJxaKwld9avLXJiiCQB2C3ZpjTPxhGiFfOKosko60ULcCDLejOTZxvqG/4n0ipsTr8oB8dEiTA== X-Received: by 2002:a17:90a:db53:: with SMTP id u19mr7808849pjx.4.1626235772271; Tue, 13 Jul 2021 21:09:32 -0700 (PDT) Received: from vultr.guest ([107.191.53.97]) by smtp.gmail.com with ESMTPSA id v23sm3675964pje.33.2021.07.13.21.09.30 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 13 Jul 2021 21:09:31 -0700 (PDT) From: Zheyu Ma To: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, sam@ravnborg.org, Zheyu Ma Subject: [PATCH v2] video: fbdev: kyro: fix a DoS bug by restricting user input Date: Wed, 14 Jul 2021 04:09:22 +0000 Message-Id: <1626235762-2590-1-git-send-email-zheyuma97@gmail.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org The user can pass in any value to the driver through the 'ioctl' interface. The driver dost not check, which may cause DoS bugs. The following log reveals it: divide error: 0000 [#1] PREEMPT SMP KASAN PTI RIP: 0010:SetOverlayViewPort+0x133/0x5f0 drivers/video/fbdev/kyro/STG4000OverlayDevice.c:476 Call Trace: kyro_dev_overlay_viewport_set drivers/video/fbdev/kyro/fbdev.c:378 [inline] kyrofb_ioctl+0x2eb/0x330 drivers/video/fbdev/kyro/fbdev.c:603 do_fb_ioctl+0x1f3/0x700 drivers/video/fbdev/core/fbmem.c:1171 fb_ioctl+0xeb/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19b/0x220 fs/ioctl.c:739 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Signed-off-by: Zheyu Ma --- Changes in v2: - Validate the inputs on a higher level --- drivers/video/fbdev/kyro/fbdev.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c index 8fbde92ae8b9..eb0cbd1d12d5 100644 --- a/drivers/video/fbdev/kyro/fbdev.c +++ b/drivers/video/fbdev/kyro/fbdev.c @@ -372,6 +372,11 @@ static int kyro_dev_overlay_viewport_set(u32 x, u32 y, u32 ulWidth, u32 ulHeight /* probably haven't called CreateOverlay yet */ return -EINVAL; + if (ulWidth == 0 || ulWidth == 0xffffffff || + ulHeight == 0 || ulHeight == 0xffffffff || + (x < 2 && ulWidth + 2 == 0)) + return -EINVAL; + /* Stop Ramdac Output */ DisableRamdacOutput(deviceInfo.pSTGReg); -- 2.17.6