From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Mark Salyzyn <salyzyn@android.com>
Cc: linux-kernel@vger.kernel.org, kernel-team@android.com,
linux-security-module@vger.kernel.org, stable@vger.kernel.org,
Miklos Szeredi <miklos@szeredi.hu>,
linux-unionfs@vger.kernel.org
Subject: Re: [PATCH] ovl: filter of trusted xattr results in audit
Date: Mon, 7 Oct 2019 18:16:16 +0200 [thread overview]
Message-ID: <20191007161616.GA988623@kroah.com> (raw)
In-Reply-To: <20191007160918.29504-1-salyzyn@android.com>
On Mon, Oct 07, 2019 at 09:09:16AM -0700, Mark Salyzyn wrote:
> When filtering xattr list for reading, presence of trusted xattr
> results in a security audit log. However, if there is other content
> no errno will be set, and if there isn't, the errno will be -ENODATA
> and not -EPERM as is usually associated with a lack of capability.
> The check does not block the request to list the xattrs present.
>
> Switch to has_capability_noaudit to reflect a more appropriate check.
>
> Signed-off-by: Mark Salyzyn <salyzyn@android.com>
> Cc: linux-security-module@vger.kernel.org
> Cc: kernel-team@android.com
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: stable@vger.kernel.org # v3.18
> Fixes: upstream a082c6f680da ("ovl: filter trusted xattr for non-admin")
> Fixes: 3.18 4bcc9b4b3a0a ("ovl: filter trusted xattr for non-admin")
> ---
> Replaced ns_capable_noaudit with 3.18.y tree specific
> has_capability_noaudit present in original submission to kernel.org
> commit 5c2e9f346b815841f9bed6029ebcb06415caf640
> ("ovl: filter of trusted xattr results in audit")
>
> fs/overlayfs/inode.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index a01ec1836a72..1175efa5e956 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -265,7 +265,8 @@ static bool ovl_can_list(const char *s)
> return true;
>
> /* Never list trusted.overlay, list other trusted for superuser only */
> - return !ovl_is_private_xattr(s) && capable(CAP_SYS_ADMIN);
> + return !ovl_is_private_xattr(s) &&
> + has_capability_noaudit(current, CAP_SYS_ADMIN);
> }
>
> ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
> --
> 2.23.0.581.g78d2f28ef7-goog
>
Thanks for the backport, this one worked!
greg k-h
next prev parent reply other threads:[~2019-10-07 16:16 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-07 16:09 [PATCH] ovl: filter of trusted xattr results in audit Mark Salyzyn
2019-10-07 16:16 ` Greg Kroah-Hartman [this message]
2019-10-07 16:17 ` Greg Kroah-Hartman
2019-10-07 16:40 ` Greg Kroah-Hartman
2019-10-07 16:43 ` Mark Salyzyn
2019-10-07 16:42 ` Mark Salyzyn
2019-10-07 16:48 ` Greg Kroah-Hartman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191007161616.GA988623@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=kernel-team@android.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=linux-unionfs@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=salyzyn@android.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).