Re: [PATCH] capabilities: Ambient capability set V2

On Sat, 28 Feb 2015, Serge E. Hallyn wrote:

Your example program is not filling in pI though?

The setcap sets the inheritance bit. When the binary runs the i bits
should be set.

Ah, i see why.  In get_file_caps() you are still assigning

	fP = pA

if the file has no file capabilities.  so then you are actually
doing

	 pP' = (X & (fP | pA)) | (pI & (fI | pA))
rather than
	 pP' = (X & fP) | (pI & (fI | pA))

I thought that fP, fI and pI = {} since the file has no caps
so this comes  out as

pP' = pA

Other than that, the patch is looking good to me.  We should
consider emitting an audit record when a task fills in its

How do I do that?

pA, and I do still wonder whether we should be requiring
CAP_SETFCAP (unsure how best to think of it).  But assuming the
fP = pA was not intended, I think this largely does the right
thing.