[patch] staging: lustre: potential underflow in mdc_iocontrol()
Dan Carpenter
dan.carpenter at oracle.com
Tue Jan 6 09:57:08 UTC 2015
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 at oracle.com>
diff --git a/drivers/staging/lustre/lustre/mdc/mdc_request.c b/drivers/staging/lustre/lustre/mdc/mdc_request.c
index 3b0f245..05d05ce 100644
--- a/drivers/staging/lustre/lustre/mdc/mdc_request.c
+++ b/drivers/staging/lustre/lustre/mdc/mdc_request.c
@@ -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;
}
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