nlmsg_len in audit netlink messages going to userspace

[Richard Guy Briggs]

Hi (primarily Eric and Steve),

In audit_log_end(), nlh->nlmsg_len is incorrectly set:
	nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN;

Since this is a known bug and anticipated by userspace, we can't change
it without disrupting userspace or somehow synchronizing a fix between
the two.

The function audit_make_reply() also generates netlink messges for
userspace, indirectly called by audit_receive_msg() cases:
	AUDIT_GET
	AUDIT_SIGNAL_INFO
	AUDIT_TTY_GET
	AUDIT_LIST_RULES
	AUDIT_GET_FEATURE

It doesn't make the same nlmsg_len change above.

Should it, to be consistent, or does userspace already know about those
being correct?


The userspace->kernel direction has recently been updated to fix all the
cases, I think.


- RGB

--
Richard Guy Briggs <rbriggs at redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545