From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754243Ab1G0Ak6 (ORCPT ); Tue, 26 Jul 2011 20:40:58 -0400 Received: from mga03.intel.com ([143.182.124.21]:51164 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753091Ab1G0AfF (ORCPT ); Tue, 26 Jul 2011 20:35:05 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,272,1309762800"; d="scan'208";a="31838618" From: Andi Kleen References: <20110726534.972201586@firstfloor.org> In-Reply-To: <20110726534.972201586@firstfloor.org> To: drosenberg@vsecurity.com, stable@kernel.org, eric.moore@lsi.com, James.Bottomley@suse.de, ak@linux.intel.com, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH] [11/98] mpt2sas: prevent heap overflows and unchecked reads Message-Id: <20110727003503.2CC022403FF@tassilo.jf.intel.com> Date: Tue, 26 Jul 2011 17:35:03 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Dan Rosenberg [ upstream commit a1f74ae82d133ebb2aabb19d181944b4e83e9960 ] At two points in handling device ioctls via /dev/mpt2ctl, user-supplied length values are used to copy data from userspace into heap buffers without bounds checking, allowing controllable heap corruption and subsequently privilege escalation. Additionally, user-supplied values are used to determine the size of a copy_to_user() as well as the offset into the buffer to be read, with no bounds checking, allowing users to read arbitrary kernel memory. Signed-off-by: Dan Rosenberg Cc: stable@kernel.org Acked-by: Eric Moore Signed-off-by: James Bottomley Signed-off-by: Andi Kleen Index: linux-2.6.35.y/drivers/scsi/mpt2sas/mpt2sas_ctl.c =================================================================== --- linux-2.6.35.y.orig/drivers/scsi/mpt2sas/mpt2sas_ctl.c +++ linux-2.6.35.y/drivers/scsi/mpt2sas/mpt2sas_ctl.c @@ -637,6 +637,13 @@ _ctl_do_mpt_command(struct MPT2SAS_ADAPT data_out_sz = karg.data_out_size; data_in_sz = karg.data_in_size; + /* Check for overflow and wraparound */ + if (karg.data_sge_offset * 4 > ioc->request_sz || + karg.data_sge_offset > (UINT_MAX / 4)) { + ret = -EINVAL; + goto out; + } + /* copy in request message frame from user */ if (copy_from_user(mpi_request, mf, karg.data_sge_offset*4)) { printk(KERN_ERR "failure at %s:%d/%s()!\n", __FILE__, __LINE__, @@ -1883,7 +1890,7 @@ _ctl_diag_read_buffer(void __user *arg, Mpi2DiagBufferPostReply_t *mpi_reply; int rc, i; u8 buffer_type; - unsigned long timeleft; + unsigned long timeleft, request_size, copy_size; u16 smid; u16 ioc_status; u8 issue_reset = 0; @@ -1919,6 +1926,8 @@ _ctl_diag_read_buffer(void __user *arg, return -ENOMEM; } + request_size = ioc->diag_buffer_sz[buffer_type]; + if ((karg.starting_offset % 4) || (karg.bytes_to_read % 4)) { printk(MPT2SAS_ERR_FMT "%s: either the starting_offset " "or bytes_to_read are not 4 byte aligned\n", ioc->name, @@ -1926,13 +1935,23 @@ _ctl_diag_read_buffer(void __user *arg, return -EINVAL; } + if (karg.starting_offset > request_size) + return -EINVAL; + diag_data = (void *)(request_data + karg.starting_offset); dctlprintk(ioc, printk(MPT2SAS_DEBUG_FMT "%s: diag_buffer(%p), " "offset(%d), sz(%d)\n", ioc->name, __func__, diag_data, karg.starting_offset, karg.bytes_to_read)); + /* Truncate data on requests that are too large */ + if ((diag_data + karg.bytes_to_read < diag_data) || + (diag_data + karg.bytes_to_read > request_data + request_size)) + copy_size = request_size - karg.starting_offset; + else + copy_size = karg.bytes_to_read; + if (copy_to_user((void __user *)uarg->diagnostic_data, - diag_data, karg.bytes_to_read)) { + diag_data, copy_size)) { printk(MPT2SAS_ERR_FMT "%s: Unable to write " "mpt_diag_read_buffer_t data @ %p\n", ioc->name, __func__, diag_data);