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From: Miklos Szeredi <miklos@szeredi.hu>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>,
	pmoore@redhat.com, Casey Schaufler <casey@schaufler-ca.com>,
	linux-kernel@vger.kernel.org,
	"linux-unionfs@vger.kernel.org" <linux-unionfs@vger.kernel.org>,
	LSM <linux-security-module@vger.kernel.org>,
	Daniel J Walsh <dwalsh@redhat.com>,
	David Howells <dhowells@redhat.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 8/9] overlayfs: Dilute permission checks on lower only if not special file
Date: Thu, 14 Jul 2016 08:51:48 +0200	[thread overview]
Message-ID: <CAJfpegsTUcDOwE6Y_2A+erSWrK+6prFe8ztj8zm0X=Nyro+Y=g@mail.gmail.com> (raw)
In-Reply-To: <1468421095-22322-9-git-send-email-vgoyal@redhat.com>

On Wed, Jul 13, 2016 at 4:44 PM, Vivek Goyal <vgoyal@redhat.com> wrote:
> Right now if file is on lower/, we remove MAY_WRITE/MAY_APPEND bits from
> mask as lower/ will never be written and file will be copied up. But this
> is not true for special files. These files are not copied up and are
> opened in place. So don't dilute the checks for these types of files.

Pushed this one as well.

Miklos

>
> Reported-by: Dan Walsh <dwalsh@redhat.com>
> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
> ---
>  fs/overlayfs/inode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index 66f42f5..6d9d86e 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -140,7 +140,7 @@ int ovl_permission(struct inode *inode, int mask)
>                 return err;
>
>         old_cred = ovl_override_creds(inode->i_sb);
> -       if (!is_upper)
> +       if (!is_upper && !special_file(realinode->i_mode))
>                 mask &= ~(MAY_WRITE | MAY_APPEND);
>         err = inode_permission(realinode, mask);
>         revert_creds(old_cred);
> --
> 2.7.4
>

  reply	other threads:[~2016-07-14  6:52 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-13 14:44 [RFC PATCH 0/9][V3] Overlayfs SELinux Support Vivek Goyal
2016-07-13 14:44 ` [PATCH 1/9] security, overlayfs: provide copy up security hook for unioned files Vivek Goyal
2016-07-13 14:52   ` Stephen Smalley
2016-07-13 14:56     ` Vivek Goyal
2016-07-13 15:13   ` Vivek Goyal
2016-07-14 14:32     ` Stephen Smalley
2016-07-13 14:44 ` [PATCH 2/9] selinux: Implementation for inode_copy_up() hook Vivek Goyal
2016-07-13 14:53   ` Stephen Smalley
2016-07-13 14:44 ` [PATCH 3/9] security,overlayfs: Provide security hook for copy up of xattrs for overlay file Vivek Goyal
2016-07-14 14:20   ` Stephen Smalley
2016-07-13 14:44 ` [PATCH 4/9] selinux: Implementation for inode_copy_up_xattr() hook Vivek Goyal
2016-07-13 14:54   ` Stephen Smalley
2016-07-13 14:44 ` [PATCH 5/9] selinux: Pass security pointer to determine_inode_label() Vivek Goyal
2016-07-13 14:56   ` Stephen Smalley
2016-07-13 14:44 ` [PATCH 6/9] security, overlayfs: Provide hook to correctly label newly created files Vivek Goyal
2016-07-13 14:57   ` Stephen Smalley
2016-07-13 14:59     ` Stephen Smalley
2016-07-14 14:29   ` Stephen Smalley
2016-07-13 14:44 ` [PATCH 7/9] selinux: Implement dentry_create_files_as() hook Vivek Goyal
2016-07-13 14:59   ` Stephen Smalley
2016-07-13 14:44 ` [PATCH 8/9] overlayfs: Dilute permission checks on lower only if not special file Vivek Goyal
2016-07-14  6:51   ` Miklos Szeredi [this message]
2016-07-13 14:44 ` [PATCH 9/9] overlayfs: Append MAY_READ when diluting write checks Vivek Goyal
2016-07-14  6:49   ` Miklos Szeredi
2016-07-21 21:16 ` [RFC PATCH 0/9][V3] Overlayfs SELinux Support Paul Moore
2016-07-21 23:09   ` James Morris
2016-07-22  7:05   ` Miklos Szeredi
2016-07-22 15:33     ` Paul Moore
2016-08-08 12:46       ` Miklos Szeredi
2016-08-08 13:18         ` Paul Moore
2016-08-09  1:19   ` Paul Moore
2016-08-10  9:11     ` Miklos Szeredi
2016-08-10 12:32       ` Paul Moore
2016-08-10 12:52         ` Daniel J Walsh
2016-08-11 12:36           ` Paul Moore
2016-08-11 12:39             ` Daniel J Walsh
2016-08-11 14:06             ` Daniel J Walsh

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