| Message ID | 20170317205234.GA2888@mwanda |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
> From: Dan Carpenter [mailto:dan.carpenter@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.carpenter@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.mody@cavium.com>
From: Dan Carpenter <dan.carpenter@oracle.com> Date: Fri, 17 Mar 2017 23:52:35 +0300 > 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.carpenter@oracle.com> Applied.
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;
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.carpenter@oracle.com>