Commit ef4356bf authored Jan 06, 2015 by Dan Carpenter Committed by Greg Kroah-Hartman Jan 17, 2015

staging: lustre: potential underflow in mdc_iocontrol()



Smatch complains that "data->ioc_plen2" is a user controlled value and,
since we cast to signed int, the limit check can underflow.  It's not
very serious because probably the copy_to_user() would return -EFAULT
on every arch that matters instead of creating an info leak.  Also I
haven't followed it through to see if the value is really user
controlled.

But definitely it would be safer to cast to unsigned so let's do that.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent d372a4cd

drivers/staging/lustre/lustre/mdc/mdc_request.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1908,8 +1908,8 @@ static int mdc_iocontrol(unsigned int cmd, struct obd_export *exp, int len,

		/* copy UUID */
		if (copy_to_user(data->ioc_pbuf2, obd2cli_tgt(obd),
		min((int) data->ioc_plen2,
		(int) sizeof(struct obd_uuid)))) {
		min_t(size_t, data->ioc_plen2,
		sizeof(struct obd_uuid)))) {
		rc = -EFAULT;
		goto out;
		}
		@@ -1921,8 +1921,8 @@ static int mdc_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
		goto out;

		if (copy_to_user(data->ioc_pbuf1, &stat_buf,
		min((int) data->ioc_plen1,
		(int) sizeof(stat_buf)))) {
		min_t(size_t, data->ioc_plen1,
		sizeof(stat_buf)))) {
		rc = -EFAULT;
		goto out;
		}