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Message-ID: <909a681238012328b0ab5499a5b66bef95247a89.camel@huaweicloud.com>
Subject: Re: [PATCH v3 5/5] ramfs: Initialize security of in-memory inodes
From: Roberto Sassu <roberto.sassu@huaweicloud.com>
To: Hugh Dickins <hughd@google.com>, Andrew Morton
 <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, 
 Roberto Sassu <roberto.sassu@huawei.com>, casey@schaufler-ca.com,
 paul@paul-moore.com, jmorris@namei.org,  serge@hallyn.com
Date: Tue, 16 Jan 2024 09:39:16 +0100
In-Reply-To: <c1ab0a9160d9220fac6e9c8c2bfa9ea493a08699.camel@huaweicloud.com>
References: <20231116090125.187209-1-roberto.sassu@huaweicloud.com>
	 <20231116090125.187209-6-roberto.sassu@huaweicloud.com>
	 <c1ab0a9160d9220fac6e9c8c2bfa9ea493a08699.camel@huaweicloud.com>
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On Fri, 2024-01-12 at 09:17 +0100, Roberto Sassu wrote:
> On Thu, 2023-11-16 at 10:01 +0100, Roberto Sassu wrote:
> > From: Roberto Sassu <roberto.sassu@huawei.com>
> >=20
> > Add a call security_inode_init_security() after ramfs_get_inode(), to l=
et
> > LSMs initialize the inode security field. Skip ramfs_fill_super(), as t=
he
> > initialization is done through the sb_set_mnt_opts hook.
> >=20
> > Calling security_inode_init_security() call inside ramfs_get_inode() is
> > not possible since, for CONFIG_SHMEM=3Dn, tmpfs also calls the former a=
fter
> > the latter.
> >=20
> > Pass NULL as initxattrs() callback to security_inode_init_security(), s=
ince
> > the purpose of the call is only to initialize the in-memory inodes.
>=20
> Hugh, Andrew, is the patch fine for you? Casey would make a PR for the
> patch set.

(I guess putting the people of interest in To instead of CC could
help...)

Friendly ping... it would be awesome if you could Ack this patch so
that Casey can still ask Linus to pull.

Thanks

Roberto

> Thanks
>=20
> Roberto
>=20
> > Cc: Hugh Dickins <hughd@google.com>
> > Cc: Andrew Morton <akpm@linux-foundation.org>
> > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> > ---
> >  fs/ramfs/inode.c | 32 +++++++++++++++++++++++++++++++-
> >  1 file changed, 31 insertions(+), 1 deletion(-)
> >=20
> > diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
> > index 4ac05a9e25bc..8006faaaf0ec 100644
> > --- a/fs/ramfs/inode.c
> > +++ b/fs/ramfs/inode.c
> > @@ -102,11 +102,20 @@ ramfs_mknod(struct mnt_idmap *idmap, struct inode=
 *dir,
> >  	int error =3D -ENOSPC;
> > =20
> >  	if (inode) {
> > +		error =3D security_inode_init_security(inode, dir,
> > +						     &dentry->d_name, NULL,
> > +						     NULL);
> > +		if (error) {
> > +			iput(inode);
> > +			goto out;
> > +		}
> > +
> >  		d_instantiate(dentry, inode);
> >  		dget(dentry);	/* Extra count - pin the dentry in core */
> >  		error =3D 0;
> >  		inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
> >  	}
> > +out:
> >  	return error;
> >  }
> > =20
> > @@ -134,6 +143,15 @@ static int ramfs_symlink(struct mnt_idmap *idmap, =
struct inode *dir,
> >  	inode =3D ramfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
> >  	if (inode) {
> >  		int l =3D strlen(symname)+1;
> > +
> > +		error =3D security_inode_init_security(inode, dir,
> > +						     &dentry->d_name, NULL,
> > +						     NULL);
> > +		if (error) {
> > +			iput(inode);
> > +			goto out;
> > +		}
> > +
> >  		error =3D page_symlink(inode, symname, l);
> >  		if (!error) {
> >  			d_instantiate(dentry, inode);
> > @@ -143,6 +161,7 @@ static int ramfs_symlink(struct mnt_idmap *idmap, s=
truct inode *dir,
> >  		} else
> >  			iput(inode);
> >  	}
> > +out:
> >  	return error;
> >  }
> > =20
> > @@ -150,12 +169,23 @@ static int ramfs_tmpfile(struct mnt_idmap *idmap,
> >  			 struct inode *dir, struct file *file, umode_t mode)
> >  {
> >  	struct inode *inode;
> > +	int error;
> > =20
> >  	inode =3D ramfs_get_inode(dir->i_sb, dir, mode, 0);
> >  	if (!inode)
> >  		return -ENOSPC;
> > +
> > +	error =3D security_inode_init_security(inode, dir,
> > +					     &file_dentry(file)->d_name, NULL,
> > +					     NULL);
> > +	if (error) {
> > +		iput(inode);
> > +		goto out;
> > +	}
> > +
> >  	d_tmpfile(file, inode);
> > -	return finish_open_simple(file, 0);
> > +out:
> > +	return finish_open_simple(file, error);
> >  }
> > =20
> >  static const struct inode_operations ramfs_dir_inode_operations =3D {
>=20