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 74DCAC77B75 for ; Mon, 8 May 2023 10:05:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234014AbjEHKFG (ORCPT ); Mon, 8 May 2023 06:05:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234015AbjEHKFE (ORCPT ); Mon, 8 May 2023 06:05:04 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F236A30165 for ; Mon, 8 May 2023 03:05:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 88A9E62327 for ; Mon, 8 May 2023 10:05:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F4C2C433D2; Mon, 8 May 2023 10:05:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683540303; bh=5Xz6DNewh+6cg6nd7xwBDceSdpGCKhYyujgZh2gky+s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bu6nk9WsAlUeFV1WfFWNLz0eFa3knvEMql0WFQdaaRvP/n8gTHNLGOxQpOQQibjXV 1OspH7h5HIdUGMYbtnAKfXL3lRAKoxbQ/9hGRdSNHGoSURkWya7Y3S/zRf04/4vMmv Rgqz7afHrk9IL54cnLqnzsLs2JSYWHVXk4lRE8c0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Leon Romanovsky , Alexander Mikhalitsyn , Paul Moore , Sasha Levin Subject: [PATCH 6.1 280/611] scm: fix MSG_CTRUNC setting condition for SO_PASSSEC Date: Mon, 8 May 2023 11:42:02 +0200 Message-Id: <20230508094431.478923956@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094421.513073170@linuxfoundation.org> References: <20230508094421.513073170@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexander Mikhalitsyn [ Upstream commit a02d83f9947d8f71904eda4de046630c3eb6802c ] Currently, kernel would set MSG_CTRUNC flag if msg_control buffer wasn't provided and SO_PASSCRED was set or if there was pending SCM_RIGHTS. For some reason we have no corresponding check for SO_PASSSEC. In the recvmsg(2) doc we have: MSG_CTRUNC indicates that some control data was discarded due to lack of space in the buffer for ancillary data. So, we need to set MSG_CTRUNC flag for all types of SCM. This change can break applications those don't check MSG_CTRUNC flag. Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Leon Romanovsky Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Alexander Mikhalitsyn v2: - commit message was rewritten according to Eric's suggestion Acked-by: Paul Moore Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/scm.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/include/net/scm.h b/include/net/scm.h index 1ce365f4c2560..585adc1346bd0 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -105,16 +105,27 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc } } } + +static inline bool scm_has_secdata(struct socket *sock) +{ + return test_bit(SOCK_PASSSEC, &sock->flags); +} #else static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) { } + +static inline bool scm_has_secdata(struct socket *sock) +{ + return false; +} #endif /* CONFIG_SECURITY_NETWORK */ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm, int flags) { if (!msg->msg_control) { - if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp) + if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp || + scm_has_secdata(sock)) msg->msg_flags |= MSG_CTRUNC; scm_destroy(scm); return; -- 2.39.2