From: Dan Rosenberg <drosenberg@vsecurity.com>
To: eric.moore@lsi.com, james.bottomley@suse.de, kashyap.desai@lsi.com
Cc: security@kernel.org, linux-scsi@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] drivers/scsi/mpt2sas: prevent heap overflows and unchecked reads
Date: Tue, 05 Apr 2011 12:45:59 -0400 [thread overview]
Message-ID: <1302021959.2082.8.camel@dan> (raw)
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.
Compile-tested only. Thanks to Eric Moore for suggestions on how to fix
this.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: stable@kernel.org
---
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 e92b77a..3834c95 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
@@ -688,6 +688,13 @@ _ctl_do_mpt_command(struct MPT2SAS_ADAPTER *ioc,
goto out;
}
+ /* 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__,
@@ -1963,7 +1970,7 @@ _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;
@@ -1999,6 +2006,8 @@ _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,
@@ -2006,13 +2015,23 @@ _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_INFO_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);
next reply other threads:[~2011-04-05 16:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-05 16:45 Dan Rosenberg [this message]
2011-04-14 6:08 ` [PATCH] drivers/scsi/mpt2sas: prevent heap overflows and unchecked reads Desai, Kashyap
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1302021959.2082.8.camel@dan \
--to=drosenberg@vsecurity.com \
--cc=eric.moore@lsi.com \
--cc=james.bottomley@suse.de \
--cc=kashyap.desai@lsi.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=security@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).