Messages in this thread | | | Date | Thu, 27 Jan 2022 12:02:25 -0500 | Subject | Re: [PATCH v9 10/23] ima: Move IMA securityfs files into ima_namespace or onto stack | From | Stefan Berger <> |
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On 1/26/22 04:40, Christian Brauner wrote: > On Tue, Jan 25, 2022 at 05:46:32PM -0500, Stefan Berger wrote: >> From: Stefan Berger <stefanb@linux.ibm.com> >> >> Only the securityfs IMA policy file is ever removed based on Kconfig >> options. For this reason, move the IMA securityfs policy file variable >> 'ima_policy' into the ima_namespace. >> >> Move the other IMA securityfs files onto the stack since they are not >> needed outside the function where they are created in. Also, their cleanup >> is automatically handled by the filesystem upon umount of a virtualized >> securityfs instance, so they don't need to be explicitly freed. > I'd reverse the explantion in the commit and mention the securityfs > change that makes this move possible which is patch 3 in this version of > the series ("securityfs: rework dentry creation"); something like: > > Earlier we simplified how dentry creation and deletion is manged in > securityfs. This allows us to move IMA securityfs files from global > variables directly into ima_fs_ns_init() itself. We can now rely on > those dentries to be cleaned up when the securityfs instance is cleaned > when the last reference to it is dropped. > > Things are slightly different for the initial ima namespace. In contrast > to non-initial ima namespaces it has pinning logic binding the lifetime > of the securityfs superblock to created dentries. We need to keep this > behavior to not regress userspace. Since ima never removes most of the > securityfs files the initial securityfs instance stays pinned. This also > means even for the initial ima namespace we don't need to keep > references to these dentries anywhere. > > The ima_policy file is the exception since ima can end up removing it if > a non-default policy is written at some point. > > Last sentence should be checked for sensibility by ima folks.
I remove the if clause and took the other text as-is...
Thanks.
Stefan
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