tree e946b82852f2e72c559a1acaa458e7d6e0173acc
parent ee618b4619b72527aaed765f0f0b74072b281159
author Eric Biggers <ebiggers@google.com> 1496929766 +0100
committer James Morris <james.l.morris@oracle.com> 1496978988 +1000

KEYS: sanitize key structs before freeing

While a 'struct key' itself normally does not contain sensitive
information, Documentation/security/keys.txt actually encourages this:

     "Having a payload is not required; and the payload can, in fact,
     just be a value stored in the struct key itself."

In case someone has taken this advice, or will take this advice in the
future, zero the key structure before freeing it.  We might as well, and
as a bonus this could make it a bit more difficult for an adversary to
determine which keys have recently been in use.

This is safe because the key_jar cache does not use a constructor.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>