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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A27FFC54EED for ; Thu, 26 Jan 2023 07:43:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233884AbjAZHnK (ORCPT ); Thu, 26 Jan 2023 02:43:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229630AbjAZHnH (ORCPT ); Thu, 26 Jan 2023 02:43:07 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 599BF1BAEB; Wed, 25 Jan 2023 23:43:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EA91B61755; Thu, 26 Jan 2023 07:43:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 054B8C433EF; Thu, 26 Jan 2023 07:43:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1674718985; bh=qLBAZG/gbjpAF8cRofsMaVMSoAZk99jH0vp77Yjg1EQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CCVJ9OZWp+IbuYSxY4Rhn4YdBs9okdhqwDqtpOVy68+MBd+rq1Ubx7+xi1unGSH32 5g4HSticgDfxZovx6bVoysxu6rzPSUFHNBgRONw3LjBp88gaW7vco2RyJD0AJp5+6T 2urMSXVL/wHFwqqo8juti32pvP4KMRGktnoitvv4= Date: Thu, 26 Jan 2023 08:43:02 +0100 From: Greg KH To: Samuel Thibault Cc: Daniel Vetter , Helge Deller , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sanan Hasanov Subject: Re: [PATCH] fbcon: Check font dimension limits Message-ID: References: <20230126004911.869923511@ens-lyon.org> <20230126004921.616264824@ens-lyon.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230126004921.616264824@ens-lyon.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 26, 2023 at 01:49:12AM +0100, Samuel Thibault wrote: > blit_x and blit_y are uint32_t, so fbcon currently cannot support fonts > larger than 32x32. "u32" you mean, right? > The 32x32 case also needs shifting an unsigned int, to properly set bit > 31, otherwise we get "UBSAN: shift-out-of-bounds in fbcon_set_font", > as reported on > > http://lore.kernel.org/all/IA1PR07MB98308653E259A6F2CE94A4AFABCE9@IA1PR07MB9830.namprd07.prod.outlook.com Odd blank line? > Kernel Branch: 6.2.0-rc5-next-20230124 > Kernel config: https://drive.google.com/file/d/1F-LszDAizEEH0ZX0HcSR06v5q8FPl2Uv/view?usp=sharing > Reproducer: https://drive.google.com/file/d/1mP1jcLBY7vWCNM60OMf-ogw-urQRjNrm/view?usp=sharing What are all of these lines for? > > Reported-by: Sanan Hasanov > Signed-off-by: Samuel Thibault What commit id does this fix? Should it go to stable kernels? > > Index: linux-6.0/drivers/video/fbdev/core/fbcon.c > =================================================================== > --- linux-6.0.orig/drivers/video/fbdev/core/fbcon.c > +++ linux-6.0/drivers/video/fbdev/core/fbcon.c > @@ -2489,9 +2489,12 @@ static int fbcon_set_font(struct vc_data > h > FBCON_SWAP(info->var.rotate, info->var.yres, info->var.xres)) > return -EINVAL; > > + if (font->width > 32 || font->height > 32) > + return -EINVAL; > + > /* Make sure drawing engine can handle the font */ > - if (!(info->pixmap.blit_x & (1 << (font->width - 1))) || > - !(info->pixmap.blit_y & (1 << (font->height - 1)))) > + if (!(info->pixmap.blit_x & (1U << (font->width - 1))) || > + !(info->pixmap.blit_y & (1U << (font->height - 1)))) Are you sure this is still needed with the above check added? If so, why? What is the difference in the compiled code? thanks, greg k-h 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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0B0F3C61D9D for ; Thu, 26 Jan 2023 07:43:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E38D910E10A; Thu, 26 Jan 2023 07:43:10 +0000 (UTC) Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6484D10E10A for ; Thu, 26 Jan 2023 07:43:08 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A9E7BB81D0C; Thu, 26 Jan 2023 07:43:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 054B8C433EF; Thu, 26 Jan 2023 07:43:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1674718985; bh=qLBAZG/gbjpAF8cRofsMaVMSoAZk99jH0vp77Yjg1EQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CCVJ9OZWp+IbuYSxY4Rhn4YdBs9okdhqwDqtpOVy68+MBd+rq1Ubx7+xi1unGSH32 5g4HSticgDfxZovx6bVoysxu6rzPSUFHNBgRONw3LjBp88gaW7vco2RyJD0AJp5+6T 2urMSXVL/wHFwqqo8juti32pvP4KMRGktnoitvv4= Date: Thu, 26 Jan 2023 08:43:02 +0100 From: Greg KH To: Samuel Thibault Subject: Re: [PATCH] fbcon: Check font dimension limits Message-ID: References: <20230126004911.869923511@ens-lyon.org> <20230126004921.616264824@ens-lyon.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230126004921.616264824@ens-lyon.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fbdev@vger.kernel.org, Sanan Hasanov , Helge Deller , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, stable@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Jan 26, 2023 at 01:49:12AM +0100, Samuel Thibault wrote: > blit_x and blit_y are uint32_t, so fbcon currently cannot support fonts > larger than 32x32. "u32" you mean, right? > The 32x32 case also needs shifting an unsigned int, to properly set bit > 31, otherwise we get "UBSAN: shift-out-of-bounds in fbcon_set_font", > as reported on > > http://lore.kernel.org/all/IA1PR07MB98308653E259A6F2CE94A4AFABCE9@IA1PR07MB9830.namprd07.prod.outlook.com Odd blank line? > Kernel Branch: 6.2.0-rc5-next-20230124 > Kernel config: https://drive.google.com/file/d/1F-LszDAizEEH0ZX0HcSR06v5q8FPl2Uv/view?usp=sharing > Reproducer: https://drive.google.com/file/d/1mP1jcLBY7vWCNM60OMf-ogw-urQRjNrm/view?usp=sharing What are all of these lines for? > > Reported-by: Sanan Hasanov > Signed-off-by: Samuel Thibault What commit id does this fix? Should it go to stable kernels? > > Index: linux-6.0/drivers/video/fbdev/core/fbcon.c > =================================================================== > --- linux-6.0.orig/drivers/video/fbdev/core/fbcon.c > +++ linux-6.0/drivers/video/fbdev/core/fbcon.c > @@ -2489,9 +2489,12 @@ static int fbcon_set_font(struct vc_data > h > FBCON_SWAP(info->var.rotate, info->var.yres, info->var.xres)) > return -EINVAL; > > + if (font->width > 32 || font->height > 32) > + return -EINVAL; > + > /* Make sure drawing engine can handle the font */ > - if (!(info->pixmap.blit_x & (1 << (font->width - 1))) || > - !(info->pixmap.blit_y & (1 << (font->height - 1)))) > + if (!(info->pixmap.blit_x & (1U << (font->width - 1))) || > + !(info->pixmap.blit_y & (1U << (font->height - 1)))) Are you sure this is still needed with the above check added? If so, why? What is the difference in the compiled code? thanks, greg k-h