> From: Dan Carpenter [mailto:dan.carpen...@oracle.com] > Sent: Friday, March 17, 2017 1:53 PM > > 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: 7afc5dbde091 ("bna: Add debugfs interface.") > Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com> > > diff --git a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c > b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c > index 05c1c1dd7751..cebfe3bd086e 100644 > --- a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c > +++ b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c > @@ -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;
You are correct, thanks Dan for adding the check. Acked-by: Rasesh Mody <rasesh.m...@cavium.com>
