bna: integer overflow bug in debugfs

We could allocate less memory than intended because we do:

	bnad->regdata = kzalloc(len << 2, GFP_KERNEL);

The shift can overflow leading to a crash.  This is debugfs code so the
impact is very small.

Fixes: 7afc5dbde0 ("bna: Add debugfs interface.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Rasesh Mody <rasesh.mody@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Carpenter 2017-03-17 23:52:35 +03:00 committed by David S. Miller
parent 6bd845d1cf
commit 13e2d5187f

View File

@ -325,7 +325,7 @@ bnad_debugfs_write_regrd(struct file *file, const char __user *buf,
return PTR_ERR(kern_buf);
rc = sscanf(kern_buf, "%x:%x", &addr, &len);
if (rc < 2) {
if (rc < 2 || len > UINT_MAX >> 2) {
netdev_warn(bnad->netdev, "failed to read user buffer\n");
kfree(kern_buf);
return -EINVAL;