Re: [PATCH 60/60] staging: lustre: libcfs: fix minimum size check for libcfs ioctl

From: James Simmons
Date: Mon Jan 30 2017 - 21:25:48 EST

> It looks like what happened is there were two patches applied out of
> sync. Let's add a fixes tag and CC the original author.

So the only problem here is the commit message. I will update it then.

> Fixes: ed2f549dc0f6 ("staging: lustre: libcfs: test if userland data is to small")
> This patch was probably correct when it was written but commit
> 1290932728e5 ("staging: lustre: Dynamic LNet Configuration (DLC) IOCTL
> changes") ended up getting applied first so the size was wrong.
> The lstcon_ioctl_entry() function doesn't have enough size checking.

This sounds like a separate patch. I will open a ticket about this and
your comments below.

> Also I'm uncomfortable with:
> data = container_of(hdr, struct libcfs_ioctl_data, ioc_hdr);
> If hdr isn't the first member of the struct then the code is broken but
> container_of() implies that that isn't a hard requirement. It should
> just be:
> data = (struct libcfs_ioctl_data *)hdr;

Don't know if hdr being first is a hard requirment. Doug, Amir do you know
if it is an requirement?