From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BFD6C7461 for ; Sun, 17 Sep 2023 20:07:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30BEAC433C7; Sun, 17 Sep 2023 20:07:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694981246; bh=b+V31BBjD3CwwNhml09pQHdTAJzNUr50Y2ienUkZMWU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nEla88/NLm+N7NEbUINd8DInP9DSl24meObPMa6e7FAqTgxrLcseTJ1OqfetVRW0t OjE6YT7agqrutOqHmJziaUsqRbj8mnDcSv8/2U8fIX1zyiXyt875Y3TGHelR94CUuC 4KtfPwNCIMbN9PHDPFDXqmPk5AWYd86EPrIz/M+o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Snowberg , Mimi Zohar , Linus Torvalds , Sasha Levin Subject: [PATCH 5.15 028/511] ovl: Always reevaluate the file signature for IMA Date: Sun, 17 Sep 2023 21:07:35 +0200 Message-ID: <20230917191114.507146954@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191113.831992765@linuxfoundation.org> References: <20230917191113.831992765@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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 5310271cf2e38..e18025b5c8872 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -2140,7 +2140,7 @@ 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