Hi Dan,
thanks for reporting this netiucv-problem. There is an implication:
Without fix, buffer values between 2**31 and 2**32 are not detected as
invalid values. Your fix would help, but since we have to touch the
code, I suggest to modernize it, moving from simple_strtoul() to
kstrtouint(). This would be the patch I have in mind:
--- a/drivers/s390/net/netiucv.c
+++ b/drivers/s390/net/netiucv.c
@@ -1564,21 +1564,21 @@ static ssize_t buffer_write (struct devi
{
struct netiucv_priv *priv = dev_get_drvdata(dev);
struct net_device *ndev = priv->conn->netdev;
- char *e;
- int bs1;
+ unsigned int bs1;
+ int rc;
IUCV_DBF_TEXT(trace, 3, __func__);
if (count >= 39)
return -EINVAL;
- bs1 = simple_strtoul(buf, &e, 0);
+ rc = kstrtouint(buf, 0, &bs1);
- if (e && (!isspace(*e))) {
- IUCV_DBF_TEXT_(setup, 2, "buffer_write: invalid char %02x\n",
- *e);
+ if (rc == -EINVAL) {
+ IUCV_DBF_TEXT_(setup, 2, "buffer_write: invalid char %s\n",
+ buf);
return -EINVAL;
}
- if (bs1 > NETIUCV_BUFSIZE_MAX) {
+ if ((rc == -ERANGE) || (bs1 > NETIUCV_BUFSIZE_MAX)) {
IUCV_DBF_TEXT_(setup, 2,
"buffer_write: buffer size %d too large\n",
bs1);
And a question about your static checker detecting this problem: Is it a
private checker, or something we could use as well?
Does your checker like my patch version?
Thanks, Ursula
On 07/14/2016 01:30 PM, Dan Carpenter wrote:
I haven't looked at the implications but we accidentally allow bs1 to
be negative. It makes my static checker complain.
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
diff --git a/drivers/s390/net/netiucv.c b/drivers/s390/net/netiucv.c
index b0e8ffd..85a5744 100644
--- a/drivers/s390/net/netiucv.c
+++ b/drivers/s390/net/netiucv.c
@@ -1578,7 +1578,7 @@ static ssize_t buffer_write (struct device *dev, struct device_attribute *attr,
*e);
return -EINVAL;
}
- if (bs1 > NETIUCV_BUFSIZE_MAX) {
+ if (bs1 < 0 || bs1 > NETIUCV_BUFSIZE_MAX) {
IUCV_DBF_TEXT_(setup, 2,
"buffer_write: buffer size %d too large\n",
bs1);
--
To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
