From patchwork Sat Jul 30 18:50:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Helge Deller X-Patchwork-Id: 12933035 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 CE148C19F2A for ; Sat, 30 Jul 2022 18:50:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230266AbiG3Sud (ORCPT ); Sat, 30 Jul 2022 14:50:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235571AbiG3Suc (ORCPT ); Sat, 30 Jul 2022 14:50:32 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6426A442; Sat, 30 Jul 2022 11:50:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1659207020; bh=lb1Lf8t4xaY9Y+QKg74YnMmqnO8vj3n92i+vvXEUpGA=; h=X-UI-Sender-Class:Date:From:To:Subject:References:In-Reply-To; b=OqCn9F5VJ0ZzU4RrAfP9GQO5F0OrM8Tr8bjpKCvVtP4itsId9U2SMQTbAmFlDCSv4 uAr6BOqixGqUSFPLDv2CuOERLaIas5fIpEkntGPTE1xhbdvZj76ECEb3UHT9MGE46I apaqNGOPUz59Wbcxkkb6AAwzGUOK0dmgGB9//wMw= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from p100 ([92.116.141.10]) by mail.gmx.net (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MWics-1nxw0K0OL2-00X1Ln; Sat, 30 Jul 2022 20:50:20 +0200 Date: Sat, 30 Jul 2022 20:50:18 +0200 From: Helge Deller To: Khalid Masum , syzbot , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Greg Kroah-Hartman , Jiri Slaby Subject: [PATCH] vt: Clear selection before changing the font Message-ID: References: <000000000000bbdd0405d120c155@google.com> <20220729065139.6529-1-khalid.masum.92@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Provags-ID: V03:K1:aOJ76y6sEpgwGrwvfAja8bpGQzr5GQjvWnu3S4B6ULoT14KB9IS 1kW0r3aNgXnf0ZQAjCzdN524HpXX3bNj2x5ReEp6m58tt6DPYuZvv4Mp4cBAdqNzbOs2q0Y 4sFI7UcoIuDhGgXx46OTbL1STGIB/oqgyMpvnc2y9xNP/swxVQGZC9k0l9ByEZ7RDiDO1o3 BDKWJaS7E2t4JTbcihZHw== X-UI-Out-Filterresults: notjunk:1;V03:K0:9vIoM7sHZEo=:mhN90fgXNBTJz11SQ1Z03B z9UUnW1mIkP+eG+jQmGYjaUMTW+e5dZIhqh/PcpFoLYPlzvIRxzA7+Pc75i3B1LmzH9VtspTI L2GBlFOqO1W9/nMxSAWx7FGKK3SYhi5MVcl0H126RzTS9CV1B53DdTrnTAEbBioJbBU2bnsBb 97R6CYHmoJ7Dz9hBSAJOXOTqmokl7mjlWkGKycnh5IHOH+hVOsgzMFCOuwKIMVt/iWLn7nQi1 m7GA9K8Kw9syj3giA0mpUUj+ic7+SwiAjuTkpWlUtnxp1J4lF2IZio6sEN1lgwXOXDeTHz0Zl idOGLyQqUAHvulM+OZxQMFxJtZ7CDGkAeb/SQZvUMWo1PAEv978gVgg8eMYdSHj/ZCAYZdNnL DToKoVs8FyB09ef4fjor7QaQpzyr238k375dJ6rv1+baBpxfcN3UoDjUxj7ArRVPRErozqRet Q3wJKaWMOdqLGbNdWkIVqLSQ8H4uRPgwq4+bndJk0llcC1Ien7t2YQJIcm4yDtI4d1S4+2fQt GXkWdAr2UcFQjGXuaYGrAyuGlxyi1oN2lDHapPqaZgMw8OEVeDZ19f9O//284hgFEvr3cOiMQ Xj+sx9MGaQuRQcW51nsh1aiadcdaKM/vHQ/PTaUGJREcHQFXpd4Ntp8P7vtPDpYamTsKPaHxW Zk8c7yC+EW6vV/YVhSjc3kUf3MOoiEnKBufYdQRLIxT7F7MLeY/c8BNHg5XU3vHsf6FmlJvry /gFK5wS87pIUbZu4ghDU1QNGCgo5CtqKpZ1z80RET5PalQ9qdNUEGOtasDqiERCqFXGl/Pbbi iS8+6E7SjdpmJ03oSorBn/xKLRflAiECYR5RJvyy8AAtHdpr8wKIWj03xk+LIkJrLShMil9QZ cGSJO27M/Lij8ESuFLDvKKt2pGJbGgVhIKDJoshGQeMayZPYgHVzemRLveevxGEHJKXbE2ouU AnGcOF2pywFkLCBOV5aP0WcnL7va4j7J/sBBzX9l4OPMgSoKvqPnTSjkComoTYGiCu8gj66MA xU5IOAWEmMLaOZcjleaAcy3nT7qHLYov3PD3UC3SPUQnAeaoVeSo8lnrySfI437iIODjGWX+l TkWWSghXt223mfkkGMZEQRnnYPZexGk0RZnhcQSHEXqjPAp8BSffj5e9Q== Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org When changing the console font with ioctl(KDFONTOP) the new font size can be bigger than the previous font. A previous selection may thus now be outside of the new screen size and thus trigger out-of-bounds accesses to graphics memory if the selection is removed in vc_do_resize(). Prevent such out-of-memory accesses by dropping the selection before the various con_font_set() console handlers are called. Signed-off-by: Helge Deller Reported-by: syzbot+14b0e8f3fd1612e35350@syzkaller.appspotmail.com Tested-by: Khalid Masum diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index dfc1f4b445f3..3f09205185a4 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -4662,9 +4662,11 @@ static int con_font_set(struct vc_data *vc, struct console_font_op *op) console_lock(); if (vc->vc_mode != KD_TEXT) rc = -EINVAL; - else if (vc->vc_sw->con_font_set) + else if (vc->vc_sw->con_font_set) { + if (vc_is_sel(vc)) + clear_selection(); rc = vc->vc_sw->con_font_set(vc, &font, op->flags); - else + } else rc = -ENOSYS; console_unlock(); kfree(font.data); @@ -4691,9 +4693,11 @@ static int con_font_default(struct vc_data *vc, struct console_font_op *op) console_unlock(); return -EINVAL; } - if (vc->vc_sw->con_font_default) + if (vc->vc_sw->con_font_default) { + if (vc_is_sel(vc)) + clear_selection(); rc = vc->vc_sw->con_font_default(vc, &font, s); - else + } else rc = -ENOSYS; console_unlock(); if (!rc) {