From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4EC4C001DE for ; Sun, 13 Aug 2023 16:06:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232586AbjHMQGC (ORCPT ); Sun, 13 Aug 2023 12:06:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232518AbjHMQFa (ORCPT ); Sun, 13 Aug 2023 12:05:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0980130D7; Sun, 13 Aug 2023 09:05:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9D89A6365B; Sun, 13 Aug 2023 16:03:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F3EABC433C7; Sun, 13 Aug 2023 16:03:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691942626; bh=2JfTtALhUSctEjgaHs5ZxvO1oFaWNCjL6JQjYKJ8GEM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Slib/q5jOqXxWIlQ0zL+q0qkhJ3U0yIQM32WvgZ16yPfSIkwPVulEdLETRdp26735 zTAY0oj01IFCPXlP9+6sLQHv61vX42gDlnqT+aA7uDqOhSPVDkHA+R2aJXDpmwWrZQ YKv8g3k0FBpRdktZw9XJs9Au64xrvYD9OPgp1cgNQEvCOclbf+mUcJKwqMZEJBnTLR kAPnSOXJgkrgz6tV1jfUMZIIE+8v8adiORvAFtIs3CApnWkQ8r17fc8ejnvPybkuEv wNDGzr3bfp0UpgbA8aGj3cO4whufTjWR3A3jG+BtkiQlG201hSrbTi8k+6gVZ31/9l xqG4ZHvRgYuQA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Snowberg , Mimi Zohar , Linus Torvalds , Sasha Levin , miklos@szeredi.hu, amir73il@gmail.com, linux-unionfs@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 40/47] ovl: Always reevaluate the file signature for IMA Date: Sun, 13 Aug 2023 11:59:35 -0400 Message-Id: <20230813160006.1073695-40-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230813160006.1073695-1-sashal@kernel.org> References: <20230813160006.1073695-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.45 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Snowberg [ Upstream commit 18b44bc5a67275641fb26f2c54ba7eef80ac5950 ] Commit db1d1e8b9867 ("IMA: use vfs_getattr_nosec to get the i_version") partially closed an IMA integrity issue when directly modifying a file on the lower filesystem. If the overlay file is first opened by a user and later the lower backing file is modified by root, but the extended attribute is NOT updated, the signature validation succeeds with the old original signature. Update the super_block s_iflags to SB_I_IMA_UNVERIFIABLE_SIGNATURE to force signature reevaluation on every file access until a fine grained solution can be found. Signed-off-by: Eric Snowberg Signed-off-by: Mimi Zohar Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/overlayfs/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 51eec4a8e82b2..08d3a1f34ac6c 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -2155,7 +2155,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) ovl_trusted_xattr_handlers; sb->s_fs_info = ofs; sb->s_flags |= SB_POSIXACL; - sb->s_iflags |= SB_I_SKIP_SYNC; + sb->s_iflags |= SB_I_SKIP_SYNC | SB_I_IMA_UNVERIFIABLE_SIGNATURE; err = -ENOMEM; root_dentry = ovl_get_root(sb, upperpath.dentry, oe); -- 2.40.1