On Wed, Jan 20, 2021 at 12:15:10PM +0100, Mickaël Salaün wrote: > > On 20/01/2021 04:55, Jarkko Sakkinen wrote: > > On Thu, Jan 14, 2021 at 04:19:03PM +0100, Mickaël Salaün wrote: > >> From: David Howells <dhowells@xxxxxxxxxx> > >> > >> KEY_FLAG_KEEP is not meant to be passed to keyring_alloc() or key_alloc(), > >> as these only take KEY_ALLOC_* flags. KEY_FLAG_KEEP has the same value as > >> KEY_ALLOC_BYPASS_RESTRICTION, but fortunately only key_create_or_update() > >> uses it. LSMs using the key_alloc hook don't check that flag. > >> > >> KEY_FLAG_KEEP is then ignored but fortunately (again) the root user cannot > >> write to the blacklist keyring, so it is not possible to remove a key/hash > >> from it. > >> > >> Fix this by adding a KEY_ALLOC_SET_KEEP flag that tells key_alloc() to set > >> KEY_FLAG_KEEP on the new key. blacklist_init() can then, correctly, pass > >> this to keyring_alloc(). > > > > OK, so thing work by luck now, but given the new patches which allow > > to append new keys they would break, right? > > Without this fix, patch 9/10 would allow to remove and modify keys from > the blacklist keyring. > > > > >> We can also use this in ima_mok_init() rather than setting the flag > >> manually. > > > > What does ima_mok_init() do? > > This was initially an addition from David Howells, I only fixed the > argument bit-ORing. ima_mok_init() allocates a blacklist keyring (with > different properties) dedicated to IMA. Please add this to the commit message. /Jarkko
