From: Xi Wang <xi.wang@gmail.com>
To: Ian Abbott <abbotti@mev.co.uk>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"devel@driverdev.osuosl.org" <devel@driverdev.osuosl.org>,
Mori Hess <fmhess@users.sourceforge.net>,
"security@kernel.org" <security@kernel.org>,
Lucas De Marchi <lucas.demarchi@profusion.mobi>,
Greg Kroah-Hartman <gregkh@suse.de>,
Ian Abbott <ian.abbott@mev.co.uk>,
Franky Lin <frankyl@broadcom.com>,
Greg Dietsche <Gregory.Dietsche@cuw.edu>,
Mark Pearson <markpearson_de@yahoo.de>
Subject: [PATCH v2] comedi: integer overflow in do_insnlist_ioctl()
Date: Wed, 23 Nov 2011 11:53:01 -0500 [thread overview]
Message-ID: <6414679A-65C7-46EA-A4D7-3CFC02780D28@gmail.com> (raw)
In-Reply-To: <4ECD1A01.3060503@mev.co.uk>
There is a potential integer overflow in do_insnlist_ioctl() if
userspace passes in a large insnlist.n_insns. The call to kmalloc()
would allocate a small buffer, leading to a memory corruption.
Reported-by: Haogang Chen <haogangchen@gmail.com>
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
---
drivers/staging/comedi/comedi_fops.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 21d8c1c..df86a9e 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -670,8 +670,9 @@ static int do_insnlist_ioctl(struct comedi_device *dev,
goto error;
}
- insns =
- kmalloc(sizeof(struct comedi_insn) * insnlist.n_insns, GFP_KERNEL);
+ if (insnlist.n_insns <= ULONG_MAX / sizeof(struct comedi_insn))
+ insns = kmalloc(sizeof(struct comedi_insn) * insnlist.n_insns,
+ GFP_KERNEL);
if (!insns) {
DPRINTK("kmalloc failed\n");
ret = -ENOMEM;
--
1.7.5.4
next prev parent reply other threads:[~2011-11-23 16:53 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-23 0:49 [PATCH] " Xi Wang
2011-11-23 6:13 ` Dan Carpenter
2011-11-23 13:59 ` Xi Wang
2011-11-23 14:50 ` Dan Carpenter
2011-11-23 16:06 ` Ian Abbott
2011-11-23 16:53 ` Xi Wang [this message]
2011-11-23 21:41 ` Lars-Peter Clausen
2011-11-23 21:51 ` Dan Carpenter
2011-11-24 19:07 ` Xi Wang
2011-11-25 7:25 ` Dan Carpenter
2011-11-25 21:46 ` [PATCH v3] " Xi Wang
2011-11-27 2:52 ` Greg KH
2011-11-27 11:25 ` Dan Carpenter
2011-11-27 21:24 ` Greg KH
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