Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933838Ab1FWRrO (ORCPT ); Thu, 23 Jun 2011 13:47:14 -0400 Received: from mail.windriver.com ([147.11.1.11]:35516 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933787Ab1FWRi3 (ORCPT ); Thu, 23 Jun 2011 13:38:29 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Dan Rosenberg , James Bottomley , Paul Gortmaker Subject: [34-longterm 223/247] mpt2sas: prevent heap overflows and unchecked reads Date: Thu, 23 Jun 2011 13:34:51 -0400 Message-Id: <1308850515-15242-164-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1308850515-15242-1-git-send-email-paul.gortmaker@windriver.com> References: <1308849690-14530-1-git-send-email-paul.gortmaker@windriver.com> <1308850515-15242-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3666 Lines: 95 From: Dan Rosenberg ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. ------------------- commit a1f74ae82d133ebb2aabb19d181944b4e83e9960 upstream. 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 Acked-by: Eric Moore Signed-off-by: James Bottomley Signed-off-by: Paul Gortmaker --- drivers/scsi/mpt2sas/mpt2sas_ctl.c | 23 +++++++++++++++++++++-- 1 files changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c b/drivers/scsi/mpt2sas/mpt2sas_ctl.c index fa9bf83..3742ac9 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c +++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c @@ -636,6 +636,13 @@ _ctl_do_mpt_command(struct MPT2SAS_ADAPTER *ioc, 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__, @@ -1877,7 +1884,7 @@ _ctl_diag_read_buffer(void __user *arg, enum block_state state) 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; @@ -1913,6 +1920,8 @@ _ctl_diag_read_buffer(void __user *arg, enum block_state state) 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, @@ -1920,13 +1929,23 @@ _ctl_diag_read_buffer(void __user *arg, enum block_state state) 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); -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/