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Message-ID: <e1c2d34acb37d85e94af15ca1edd162e1e7f9a2a.camel@linux.ibm.com>
Subject: Re: [PATCH 2/2] fs: extend the trusted_for syscall to call IMA
From:   Mimi Zohar <zohar@linux.ibm.com>
To:     =?ISO-8859-1?Q?Micka=EBl_Sala=FCn?= <mic@digikod.net>
Cc:     Al Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        Casey Schaufler <casey@schaufler-ca.com>
Date:   Wed, 13 Oct 2021 11:45:01 -0400
In-Reply-To: <d4273866-607e-37be-076b-a920bbf08bf9@digikod.net>
References: <20211013110113.13239-1-zohar@linux.ibm.com>
         <20211013110113.13239-2-zohar@linux.ibm.com>
         <d4273866-607e-37be-076b-a920bbf08bf9@digikod.net>
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[CC'ing Casey]

On Wed, 2021-10-13 at 17:26 +0200, Micka?l Sala?n wrote:
> Nice!
> 
> On 13/10/2021 13:01, Mimi Zohar wrote:
> > Extend the trusted_for syscall to call the newly defined
> > ima_trusted_for hook.
> > 
> > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
> > ---
> >  fs/open.c           | 3 +++
> >  include/linux/ima.h | 9 +++++++++
> >  2 files changed, 12 insertions(+)
> > 
> > diff --git a/fs/open.c b/fs/open.c
> > index c79c138a638c..4d54e2a727e1 100644
> > --- a/fs/open.c
> > +++ b/fs/open.c
> > @@ -585,6 +585,9 @@ SYSCALL_DEFINE3(trusted_for, const int, fd, const enum trusted_for_usage, usage,
> >  	err = inode_permission(file_mnt_user_ns(f.file), inode,
> >  			mask | MAY_ACCESS);
> >  
> > +	if (!err)
> > +		err = ima_trusted_for(f.file, usage);
> 
> Could you please implement a new LSM hook instead? Other LSMs may want
> to use this information as well.

Casey normally pushes back on my defining a new LSM hook, when IMA is
the only user.  If any of the LSM maintainers are planning on defining
this hook, please chime in.

thanks,

Mimi