From nobody Thu Sep 18 05:56:41 2025 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 31156C4332F for ; Fri, 9 Dec 2022 11:28:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229717AbiLIL2M (ORCPT ); Fri, 9 Dec 2022 06:28:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229964AbiLIL15 (ORCPT ); Fri, 9 Dec 2022 06:27:57 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD86D396C4; Fri, 9 Dec 2022 03:27:56 -0800 (PST) Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2B99U7YO012471; Fri, 9 Dec 2022 11:27:54 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=pz6m1Fl1hTAMA9HWy+BsrRjV4oX0XBMq5Eof4xY6s8A=; b=JXlFAsEJTVnZ/VystQt6zpuw0KRfSMCB3gSKNrxSnAq1M7Meyjp+O6xzxN2oR9aDMkjA rLuRnFge5aNiYDLGt4nEaLEBdjwvNwuWvrVDR4eQs664lVBmMSk3J/I+Uqo8kDxfgjM0 +MT21xBaEhCPlaNeNVeDY05FOC64L8vmMDCqhx4WdF07nQGtE1V1VT6g32upB7GEDGW5 /Etv0GKm58p/PTpwL264FodCdD6dS1rG9EGIkzPl3fcK49CkS7/Y71+dKGqjzgiyZKZw KpDdUGq+p8FzFcCzIPVk9fIWm1dHkE0sgbOw5kw3d8FJf2YRFBs7vq2DrB/56/E7Pbqz WQ== Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3mbrjkf04w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 09 Dec 2022 11:27:53 +0000 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 2B8Lb9uh027356; Fri, 9 Dec 2022 11:27:51 GMT Received: from smtprelay02.fra02v.mail.ibm.com ([9.218.2.226]) by ppma04ams.nl.ibm.com (PPS) with ESMTPS id 3m9ks45w92-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 09 Dec 2022 11:27:51 +0000 Received: from smtpav01.fra02v.mail.ibm.com (smtpav01.fra02v.mail.ibm.com [10.20.54.100]) by smtprelay02.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 2B9BRlVO40436098 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 9 Dec 2022 11:27:47 GMT Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3F78B20049; Fri, 9 Dec 2022 11:27:47 +0000 (GMT) Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2E77420040; Fri, 9 Dec 2022 11:27:47 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by smtpav01.fra02v.mail.ibm.com (Postfix) with ESMTPS; Fri, 9 Dec 2022 11:27:47 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 55390) id E6DC6E027E; Fri, 9 Dec 2022 12:27:46 +0100 (CET) From: Sven Schnelle To: Greg Kroah-Hartman , Jiri Slaby Cc: Christian Borntraeger , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH v2 1/2] tty: fix out-of-bounds access in tty_driver_lookup_tty() Date: Fri, 9 Dec 2022 12:27:36 +0100 Message-Id: <20221209112737.3222509-2-svens@linux.ibm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221209112737.3222509-1-svens@linux.ibm.com> References: <20221209112737.3222509-1-svens@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: SUuO4uooI-8Oa7dRGxZ8g73z6p6RLqLY X-Proofpoint-ORIG-GUID: SUuO4uooI-8Oa7dRGxZ8g73z6p6RLqLY X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-12-09_04,2022-12-08_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 spamscore=0 mlxscore=0 priorityscore=1501 bulkscore=0 lowpriorityscore=0 impostorscore=0 adultscore=0 clxscore=1015 malwarescore=0 mlxlogscore=948 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2212090066 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When specifying an invalid console=3D device like console=3Dtty3270, tty_driver_lookup_tty() returns the tty struct without checking whether index is a valid number. To reproduce: qemu-system-x86_64 -enable-kvm -nographic -serial mon:stdio \ -kernel ../linux-build-x86/arch/x86/boot/bzImage \ -append "console=3DttyS0 console=3Dtty3270" This crashes with: [ 0.770599] BUG: kernel NULL pointer dereference, address: 0000000000000= 0ef [ 0.771265] #PF: supervisor read access in kernel mode [ 0.771773] #PF: error_code(0x0000) - not-present page [ 0.772609] Oops: 0000 [#1] PREEMPT SMP PTI [ 0.774878] RIP: 0010:tty_open+0x268/0x6f0 [ 0.784013] chrdev_open+0xbd/0x230 [ 0.784444] ? cdev_device_add+0x80/0x80 [ 0.784920] do_dentry_open+0x1e0/0x410 [ 0.785389] path_openat+0xca9/0x1050 [ 0.785813] do_filp_open+0xaa/0x150 [ 0.786240] file_open_name+0x133/0x1b0 [ 0.786746] filp_open+0x27/0x50 [ 0.787244] console_on_rootfs+0x14/0x4d [ 0.787800] kernel_init_freeable+0x1e4/0x20d [ 0.788383] ? rest_init+0xc0/0xc0 [ 0.788881] kernel_init+0x11/0x120 [ 0.789356] ret_from_fork+0x22/0x30 Signed-off-by: Sven Schnelle Reviewed-by: Jiri Slaby --- drivers/tty/tty_io.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index de06c3c2ff70..1ac6784ea1f9 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1224,14 +1224,16 @@ static struct tty_struct *tty_driver_lookup_tty(str= uct tty_driver *driver, { struct tty_struct *tty; =20 - if (driver->ops->lookup) + if (driver->ops->lookup) { if (!file) tty =3D ERR_PTR(-EIO); else tty =3D driver->ops->lookup(driver, file, idx); - else + } else { + if (idx >=3D driver->num) + return ERR_PTR(-EINVAL); tty =3D driver->ttys[idx]; - + } if (!IS_ERR(tty)) tty_kref_get(tty); return tty; --=20 2.34.1 From nobody Thu Sep 18 05:56:41 2025 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 71E4AC4332F for ; Fri, 9 Dec 2022 11:28:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229545AbiLIL2S (ORCPT ); Fri, 9 Dec 2022 06:28:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229968AbiLIL2A (ORCPT ); Fri, 9 Dec 2022 06:28:00 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E72A045A3A; 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Fri, 9 Dec 2022 11:27:47 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 55390) id 8656BE027E; Fri, 9 Dec 2022 12:27:47 +0100 (CET) From: Sven Schnelle To: Greg Kroah-Hartman , Jiri Slaby Cc: Christian Borntraeger , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH v2 2/2] tty/vt: prevent registration of console with invalid number Date: Fri, 9 Dec 2022 12:27:37 +0100 Message-Id: <20221209112737.3222509-3-svens@linux.ibm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221209112737.3222509-1-svens@linux.ibm.com> References: <20221209112737.3222509-1-svens@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 2CbJFMTMhpsNEWfV2R6OLT-wR3N1LIQk X-Proofpoint-ORIG-GUID: 2CbJFMTMhpsNEWfV2R6OLT-wR3N1LIQk X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-12-09_04,2022-12-08_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 clxscore=1015 mlxlogscore=774 impostorscore=0 mlxscore=0 lowpriorityscore=0 phishscore=0 priorityscore=1501 adultscore=0 suspectscore=0 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2212090066 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If a user specifies an invalid console like 'console=3Dtty3000', the vt driver should prevent setting up a vt entry for that. Suggested-by: Jiri Slaby Signed-off-by: Sven Schnelle --- drivers/tty/vt/vt.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 981d2bfcf9a5..62c8a45ad731 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -3156,8 +3156,14 @@ static struct tty_driver *vt_console_device(struct c= onsole *c, int *index) return console_driver; } =20 +static int vt_console_setup(struct console *co, char *options) +{ + return co->index >=3D MAX_NR_CONSOLES ? -EINVAL : 0; +} + static struct console vt_console_driver =3D { .name =3D "tty", + .setup =3D vt_console_setup, .write =3D vt_console_print, .device =3D vt_console_device, .unblank =3D unblank_screen, --=20 2.34.1