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From:   Jann Horn <jannh@google.com>
Date:   Thu, 29 Oct 2020 02:06:21 +0100
Message-ID: <CAG48ez0venF9OnBG82yc8U+px1LUfUU498f1kJxYMu0hcU0+-A@mail.gmail.com>
Subject: Re: [PATCH v22 06/12] fs,security: Add sb_delete hook
To:     =?UTF-8?B?TWlja2HDq2wgU2FsYcO8bg==?= <mic@digikod.net>
Cc:     James Morris <jmorris@namei.org>,
        "Serge E . Hallyn" <serge@hallyn.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Andy Lutomirski <luto@amacapital.net>,
        Anton Ivanov <anton.ivanov@cambridgegreys.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Casey Schaufler <casey@schaufler-ca.com>,
        Jeff Dike <jdike@addtoit.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Kees Cook <keescook@chromium.org>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        Richard Weinberger <richard@nod.at>,
        Shuah Khan <shuah@kernel.org>,
        Vincent Dagonneau <vincent.dagonneau@ssi.gouv.fr>,
        Kernel Hardening <kernel-hardening@lists.openwall.com>,
        Linux API <linux-api@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        kernel list <linux-kernel@vger.kernel.org>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        linux-security-module <linux-security-module@vger.kernel.org>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        =?UTF-8?B?TWlja2HDq2wgU2FsYcO8bg==?= <mic@linux.microsoft.com>
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On Tue, Oct 27, 2020 at 9:04 PM Micka=C3=ABl Sala=C3=BCn <mic@digikod.net> =
wrote:
> The sb_delete security hook is called when shutting down a superblock,
> which may be useful to release kernel objects tied to the superblock's
> lifetime (e.g. inodes).
>
> This new hook is needed by Landlock to release (ephemerally) tagged
> struct inodes.  This comes from the unprivileged nature of Landlock
> described in the next commit.
>
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Cc: James Morris <jmorris@namei.org>
> Cc: Jann Horn <jannh@google.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Serge E. Hallyn <serge@hallyn.com>
> Signed-off-by: Micka=C3=ABl Sala=C3=BCn <mic@linux.microsoft.com>

Reviewed-by: Jann Horn <jannh@google.com>