From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mimi Zohar Date: Mon, 14 Jan 2019 16:10:51 +0000 Subject: Re: [RFC PATCH 2/2] kexec, KEYS: Make use of platform keyring for signature verify Message-Id: <1547482251.4156.127.camel@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit List-Id: References: <20190109164824.19708-1-kasong@redhat.com> <20190109164824.19708-3-kasong@redhat.com> <20190111134303.GA12760@dhcp-128-65.nay.redhat.com> <1547223220.19931.471.camel@linux.ibm.com> <20190113013958.GA14019@dhcp-128-65.nay.redhat.com> In-Reply-To: <20190113013958.GA14019@dhcp-128-65.nay.redhat.com> To: Dave Young Cc: Kairui Song , linux-kernel@vger.kernel.org, dhowells@redhat.com, dwmw2@infradead.org, jwboyer@fedoraproject.org, keyrings@vger.kernel.org, jmorris@namei.org, serge@hallyn.com, bauerman@linux.ibm.com, ebiggers@google.com, nayna@linux.ibm.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org On Sun, 2019-01-13 at 09:39 +0800, Dave Young wrote: > Hi, > > On 01/11/19 at 11:13am, Mimi Zohar wrote: > > On Fri, 2019-01-11 at 21:43 +0800, Dave Young wrote: > > [snip] > > > > > Personally I would like to see platform key separated from integrity. > > > But for the kexec_file part I think it is good at least it works with > > > this fix. > > > > > > Acked-by: Dave Young > > > > The original "platform" keyring patches that Nayna posted multiple > > times were in the certs directory, but nobody commented/responded.  So > > she reworked the patches, moving them to the integrity directory and > > posted them (cc'ing the kexec mailing list).  It's a bit late to be > > asking to move it, isn't it? > > Hmm, apologize for being late, I did not get chance to have a look the > old series. Since we have the needs now, it should be still fine > > Maybe Kairui can check Nayna's old series, see if he can do something > again? Whether the platform keyring is defined in certs/ or in integrity/ the keyring id needs to be accessible to the other, without making the keyring id global.  Moving where the platform keyring is defined is not the problem. Commit a210fd32a46b ("kexec: add call to LSM hook in original kexec_load syscall") introduced a new LSM hook.  Assuming CONFIG_KEXEC_VERIFY_SIG is enabled, with commit b5ca117365d9 ("ima: prevent kexec_load syscall based on runtime secureboot flag") we can now block the kexec_load syscall.  Without being able to block the kexec_load syscall, verifying the kexec image signature via the kexec_file_load syscall is kind of pointless. Unless you're planning on writing an LSM to prevent the kexec_load syscall, I assume you'll want to enable integrity anyway. Mimi