x86: PHYSDEVOP_{prepare,release}_msix are privileged

Yet this wasn't being enforced.

This is XSA-87.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 9c7e789a1b60b6114e0b1ef16dff95f03f532fb5
master date: 2014-01-24 13:41:36 +0100
flask: restrict allocations done by hypercall interface

Other than in 4.2 and newer, we're not having an overflow issue here,
but uncontrolled exposure of the operations opens the host to be driven
out of memory by an arbitrary guest. Since all operations other than
FLASK_LOAD simply deal with ASCII strings, limiting the allocations
(and incoming buffer sizes) to a page worth of memory seems like the
best thing we can do.

Consequently, in order to not expose the larger allocation to arbitrary
guests, the permission check for FLASK_LOAD needs to be pulled ahead of
the allocation (and it's perhaps worth noting that - afaict - it was
pointlessly done with the sel_sem spin lock held).

Note that this breaks FLASK_AVC_CACHESTATS on systems with sufficiently
many CPUs (as requiring a buffer bigger than PAGE_SIZE there). No
attempt is made to address this here, as it would needlessly complicate
this fix with rather little gain.

This is XSA-84.

Reported-by: Matthew Daley <mattd@bugfuzz.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>

The index of boolean variables in FLASK_{GET,SET}BOOL was not always
checked against the bounds of the array.

Reported-by: John McDermott <john.mcdermott@nrl.navy.mil>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
libxc: Fix out-of-memory error handling in xc_cpupool_getinfo()

Avoid freeing info then returning it to the caller.

This is XSA-88.

Coverity-ID: 1056192
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit d883c179a74111a6804baf8cb8224235242a88fc)