From: "Jarkko Sakkinen" <jarkko@kernel.org>
To: "Jann Horn" <jannh@google.com>,
"Paul Moore" <paul@paul-moore.com>,
"James Morris" <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
"John Johansen" <john.johansen@canonical.com>,
"David Howells" <dhowells@redhat.com>,
"Mickaël Salaün" <mic@digikod.net>,
"Günther Noack" <gnoack@google.com>,
"Stephen Smalley" <stephen.smalley.work@gmail.com>,
"Ondrej Mosnacek" <omosnace@redhat.com>,
"Casey Schaufler" <casey@schaufler-ca.com>
Cc: <linux-kernel@vger.kernel.org>,
<linux-security-module@vger.kernel.org>,
<apparmor@lists.ubuntu.com>, <keyrings@vger.kernel.org>,
<selinux@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] KEYS: use synchronous task work for changing parent credentials
Date: Thu, 15 Aug 2024 21:10:22 +0300 [thread overview]
Message-ID: <D3GOR6ZR0MPL.2O29DCFWQ77RA@kernel.org> (raw)
In-Reply-To: <20240805-remove-cred-transfer-v2-1-a2aa1d45e6b8@google.com>
On Mon Aug 5, 2024 at 2:54 PM EEST, Jann Horn wrote:
> keyctl_session_to_parent() involves posting task work to the parent task,
> with work function key_change_session_keyring.
> Because the task work in the parent runs asynchronously, no errors can be
> returned back to the caller of keyctl_session_to_parent(), and therefore
> the work function key_change_session_keyring() can't be allowed to fail due
> to things like memory allocation failure or permission checks - all
> allocations and checks have to happen in the child.
>
> This is annoying for two reasons:
>
> - It is the only reason why cred_alloc_blank() and
> security_transfer_creds() are necessary.
> - It means we can't do synchronous permission checks.
I agree with this premise. Also I think the code change is reasonable.
I'd like to see a comment from David tho.
BR, Jarkko
next prev parent reply other threads:[~2024-08-15 18:10 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-05 11:54 [PATCH v2 0/2] get rid of cred_transfer Jann Horn
2024-08-05 11:54 ` [PATCH v2 1/2] KEYS: use synchronous task work for changing parent credentials Jann Horn
2024-08-15 18:10 ` Jarkko Sakkinen [this message]
2024-09-10 21:07 ` Paul Moore
2024-09-10 23:05 ` Jann Horn
2024-08-05 11:54 ` [PATCH v2 2/2] security: remove unused cred_alloc_blank/cred_transfer helpers Jann Horn
2024-08-15 18:12 ` Jarkko Sakkinen
2024-08-15 19:46 ` Can KEYCTL_SESSION_TO_PARENT be dropped entirely? -- was Re: [PATCH v2 1/2] KEYS: use synchronous task work for changing parent credentials David Howells
2024-08-15 19:59 ` Jann Horn
2024-08-16 10:52 ` Jarkko Sakkinen
2024-09-10 20:49 ` Paul Moore
2024-09-16 10:46 ` Paul Moore
2024-09-16 21:14 ` Jann Horn
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