genetlink: reject use of nlmsg_flags for new commands

Commit 9c5d03d36251 ("genetlink: start to validate reserved header bytes")
introduced extra validation for genetlink headers. We had to gate it
to only apply to new commands, to maintain bug-wards compatibility.
Use this opportunity (before the new checks make it to Linus's tree)
to add more conditions.

Validate that Generic Netlink families do not use nlmsg_flags outside
of the well-understood set.

Link: https://lore.kernel.org/all/[email protected]/
Reviewed-by: Johannes Berg <[email protected]>
Acked-by: Nikolay Aleksandrov <[email protected]>
Reviewed-by: Nicolas Dichtel <[email protected]>
Reviewed-by: Guillaume Nault <[email protected]>
Reviewed-by: Jacob Keller <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

0 files changed, 0 insertions, 0 deletions