From patchwork Fri Jul 1 20:23:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Helge Deller X-Patchwork-Id: 586379 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 C63F9C43334 for ; Fri, 1 Jul 2022 20:24:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229846AbiGAUYE (ORCPT ); Fri, 1 Jul 2022 16:24:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230294AbiGAUYC (ORCPT ); Fri, 1 Jul 2022 16:24:02 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 062263AA6D for ; Fri, 1 Jul 2022 13:23:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1656707034; bh=dEefPiI9Wq3+N76bPKdFvUHz0EeUTEIRh3WCR7KXkgA=; h=X-UI-Sender-Class:From:To:Subject:Date:In-Reply-To:References; b=HEFt5iZDmNZf66zk+qkPjL3tW/l2Fg/mj39IwVLc9Udj7wk4mo3GOy8hvIzKNSMjZ 1gIakjLvxkq8vz/kDjPdv/khMXrT2wdDiBLpUteax/9On9UcojFbz6WKfb3RJBtpFX zKPl6vMnyG8dRvOH6jql54+NqKx8HkZPl5XNYvoU= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from p100.fritz.box ([92.116.182.192]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MsHnm-1nn6Ad44zK-00ticg; Fri, 01 Jul 2022 22:23:54 +0200 From: Helge Deller To: geert@linux-m68k.org, dri-devel@lists.freedesktop.org, daniel.vetter@ffwll.ch, linux-fbdev@vger.kernel.org Subject: [PATCH v2 3/4] fbmem: Prevent invalid virtual screen sizes in fb_set_var() Date: Fri, 1 Jul 2022 22:23:51 +0200 Message-Id: <20220701202352.559808-4-deller@gmx.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220701202352.559808-1-deller@gmx.de> References: <20220701202352.559808-1-deller@gmx.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:Bf8VXfaa577fpq4acsmdWzYRjRzn9t3d4jS+k3688Br3xPNGmzP p53HnFCs0503W6wMD/41hpxfgpasIAVFfi+0BsK0Vaca5CnYMrAq92Vt4Tv+y1NmmzQs91o sVc5gGs3GeWTC2v0TTBIXaXv/f8fpwtPuDlMwKHBivevR9eRdM3KlUOT4Ma599iz18mKGA0 zulyQJ8I7gZN6XhQyLMUw== X-UI-Out-Filterresults: notjunk:1;V03:K0:Vw9SFYftwds=:rr4MBShpbjEyzFIUlufOTC c/MzOQWgDKdqqI6ErlQQSs7fvS6fRhtrRcuAtfnXFGwMl3llbzURBcbqajh2yuL4CnGqOY/im qxSAxrVThZlQNTnuErbRtOS5D1Ib4TobV9FaN8k2wSqNskvY/JdatfT9PwqyaCQbZ4JQ4y8u8 KNiSxIpYQ0qvVGYzwUG2PtUGoHYc9PAa7tBFoScRv9AuLwykZ2SUwCALRysMGJHo8RAMbojOw HCL6o+uJQd+sHpSCC9SnXktaDTJPklX8cJE67vWppHC40YA84O4GDdrcJUEhmxyTeGsmGJhbk 9OAd2RlR3kvKZSu7mPe+QPIoFj/v8MS2XaohZ+hQiR+GS7MhauN7cCcFRd+pM0baSQnnstYSC TRqfUD/QZ0xh8exiFubK/APbIr7nxJRxfPQxlI5NQctBPP/YJZlQuIeUN4Cozr2+0lnxs4Dsa oP1RdkF5V5RVEP1wpg56ZIpoJvA/LoiV5+HQ7Htn2r+0biNhPWEEyJ/hbhmhZTQcU3GhVPsJL jR+5Iujjv2NYaR17ipV61J7X+4yJPOUVvANCSvtbkcE+MRW/wqlUfYcWkxdBykhumrzqeqbQf YIt+mJS/8l5f6jZ+LzOuZ2gRoLQm2yfqyaFXQN0quCzF2l+OQErY7ZKU6HbfbIHey8vNqG1AX 75EpJwWfycUEiHmRrP9mkETt/kPVECtqnJJjNn32GXg4TRN6fAAfMRAOxJavcluEUuyal7EJz CJbnLMsB1UiwBif7hdyZ4+ttwl+EWWS59Uq0JFduXObZ0VAMthoMccSdRlYiT/vL6bTZjSNHy TEW34N4LBqpeXkMDScqnsQarwjqDFV60vsxC1FNemFWYS4FYHziLU4er5jAt+eyu6/zzbMlNG w8/ukmPmX4bUizk4xvTy7j60pICkSFog6EK5AYmaS51zyWZCU8ccJT6v4txKvxkLhx2z3A2s+ MYpXwZrMRyh+0uZWAbTHWv+wwT8dCmsclOjVRO6Y5aQlT7s14YkMvHsItJGuITDMtdKNvrF8o OMrCmoMZ6LK0Wh4HJUj6EB0qnDehIoyzoJJF4BNJEn64pDQP/A/73hTjkQmTRNcltxtbhPkIU 1M0pF0YtNlgIBkko68snz3nUE5vQLlK1s6jcdZZCFGh99qG760rPGZy/Q== Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Prevent that drivers configure a virtual screen resolution smaller than the physical screen resolution. This is important, because otherwise we may access memory outside of the graphics memory area. Give a kernel WARNing and show the driver name to help locating the buggy driver. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Helge Deller --- drivers/video/fbdev/core/fbmem.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) -- 2.35.3 diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 160389365a36..e8f06d26803c 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1016,6 +1016,18 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var) if (ret) return ret; + /* make sure virtual resolution >= physical resolution */ + if (WARN_ON(var->xres_virtual < var->xres)) { + pr_warn("fbcon: Fix up invalid xres %d for %s\n", + var->xres_virtual, info->fix.id); + var->xres_virtual = var->xres; + } + if (WARN_ON(var->yres_virtual < var->yres)) { + pr_warn("fbcon: Fix up invalid yres %d for %s\n", + var->yres_virtual, info->fix.id); + var->yres_virtual = var->yres; + } + if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW) return 0;