Paul Moore <paul@xxxxxxxxxxxxxx> writes: > On July 22, 2022 2:12:03 AM Martin KaFai Lau <kafai@xxxxxx> wrote: > >> On Thu, Jul 21, 2022 at 12:28:04PM -0500, Frederick Lawler wrote: >>> While creating a LSM BPF MAC policy to block user namespace creation, we >>> used the LSM cred_prepare hook because that is the closest hook to prevent >>> a call to create_user_ns(). >>> >>> The calls look something like this: >>> >>> cred = prepare_creds() >>> security_prepare_creds() >>> call_int_hook(cred_prepare, ... >>> if (cred) >>> create_user_ns(cred) >>> >>> We noticed that error codes were not propagated from this hook and >>> introduced a patch [1] to propagate those errors. >>> >>> The discussion notes that security_prepare_creds() >>> is not appropriate for MAC policies, and instead the hook is >>> meant for LSM authors to prepare credentials for mutation. [2] >>> >>> Ultimately, we concluded that a better course of action is to introduce >>> a new security hook for LSM authors. [3] >>> >>> This patch set first introduces a new security_create_user_ns() function >>> and userns_create LSM hook, then marks the hook as sleepable in BPF. >> Patch 1 and 4 still need review from the lsm/security side. > > > This patchset is in my review queue and assuming everything checks > out, I expect to merge it after the upcoming merge window closes. It doesn't even address my issues with the last patchset. So it has my NACK. Eric
