linux-kernel - [PATCH v2] staging/comedi: Fix undefined array subscript

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1360765694-3748-1-git-send-email-peterhuewe@gmx.de>
Date:	Wed, 13 Feb 2013 15:28:14 +0100
From:	Peter Huewe <peterhuewe@....de>
To:	Ian Abbott <abbotti@....co.uk>
Cc:	Mori Hess <fmhess@...rs.sourceforge.net>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	H Hartley Sweeten <hsweeten@...ionengravers.com>,
	devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org,
	Peter Huewe <peterhuewe@....de>
Subject: [PATCH v2] staging/comedi: Fix undefined array subscript

In vmk80xx_do_insn_bits the local variable reg, which is used as an
index to the tx_buf array, can be used uninitialized if
- data[0] == 0
and
- devpriv->model != VMK8061_MODEL
-> we get into the else branch without having reg initialized.

Since the driver usually differentiates between VMK8061_MODEL and
VMK8055_MODEL it's safe to assume that VMK8055_DO_REG was meant as an
initial value.

And to avoid duplication we can move the assignments to the top.

Acked-by: Ian Abbott <abbotti@....co.uk>
Signed-off-by: Peter Huewe <peterhuewe@....de>
---
 drivers/staging/comedi/drivers/vmk80xx.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/comedi/drivers/vmk80xx.c b/drivers/staging/comedi/drivers/vmk80xx.c
index ebf2d48..eed46ee 100644
--- a/drivers/staging/comedi/drivers/vmk80xx.c
+++ b/drivers/staging/comedi/drivers/vmk80xx.c
@@ -675,8 +675,14 @@ static int vmk80xx_do_insn_bits(struct comedi_device *dev,
 	if (data[0])
 		dir |= DIR_OUT;
 
-	if (devpriv->model == VMK8061_MODEL)
+	if (devpriv->model == VMK8061_MODEL) {
 		dir |= DIR_IN;
+		reg = VMK8061_DO_REG;
+		cmd = VMK8061_CMD_DO;
+	} else { /* VMK8055_MODEL */
+		reg = VMK8055_DO_REG;
+		cmd = VMK8055_CMD_WRT_AD;
+	}
 
 	retval = rudimentary_check(devpriv, dir);
 	if (retval)
@@ -688,14 +694,6 @@ static int vmk80xx_do_insn_bits(struct comedi_device *dev,
 	tx_buf = devpriv->usb_tx_buf;
 
 	if (data[0]) {
-		if (devpriv->model == VMK8055_MODEL) {
-			reg = VMK8055_DO_REG;
-			cmd = VMK8055_CMD_WRT_AD;
-		} else { /* VMK8061_MODEL */
-			reg = VMK8061_DO_REG;
-			cmd = VMK8061_CMD_DO;
-		}
-
 		tx_buf[reg] &= ~data[0];
 		tx_buf[reg] |= (data[0] & data[1]);
 
@@ -706,7 +704,6 @@ static int vmk80xx_do_insn_bits(struct comedi_device *dev,
 	}
 
 	if (devpriv->model == VMK8061_MODEL) {
-		reg = VMK8061_DO_REG;
 		tx_buf[0] = VMK8061_CMD_RD_DO;
 
 		retval = vmk80xx_read_packet(devpriv);
-- 
1.7.8.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/