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 036DD3D994 for ; Sun, 12 Apr 2026 20:02:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776024174; cv=none; b=hqLIFfdOUteaJzYy7qSeZETz7cmUFnx4zbZjnpExbve34yfySkHRGEfTMu2aEZX/9bSXbeyuJvslffqTMnzZi+VlGeSfgs+rPPXojL/wyQlHLvSXUGS+JzHLXP5355OMJkL/mGiYgYHpjXtpUtX5O9Ep0ixkIBr3aELNhIfdmc8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776024174; c=relaxed/simple; bh=xaR01DCqfuhnTtupYzR6lcnuU3QeZUVkGVSnkD8ZQbA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=D1fJc9DUdgM4yro+wGEkSYcmDU5yWa0IlHPxP1pevKw2HpjyvHAgp/pLZVkkBKN1rtsN+G+t4vr00vpD2OaHcYN4xnl/lUl/p7QErWLglXcJEJasOZqiKMueHIaLVezcU1h8xJq2gVGDO4hNqR8dUD20AvSV8Dj0TOBKpLwcyyM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DmJGIahU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DmJGIahU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C2BDC19424; Sun, 12 Apr 2026 20:02:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776024173; bh=xaR01DCqfuhnTtupYzR6lcnuU3QeZUVkGVSnkD8ZQbA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DmJGIahUpLWPk5tw1QW2opKpYr0lF3ZrpyhP40mAnPl4k2vryGTvaW4MNLckidcFA MitZkasBW2/rLQdxgKEOhA5qxudE+fp2A53AwBmLgunwz1KIiW6xHUkAmbrTmCG19p cHr3SXMYoQLxSu+eHhqxC2HynUfBH1sxldxWJUexga+Dp083XGw56RtSnTugwX0oGt PEe+2k4vtsoh5nfz9WsZmW06EwnpmPs7cJY1sWNY/R7qHENVPT8MaIl9X9mcS2GG2D yho5whplFxsMN/+dcBguzlnu2B0mGeg/yPPNErcz6H+yoq869bd42g+EqAcNr3wtkD LB/FJN8PHnWyA== From: Sasha Levin To: stable@vger.kernel.org Cc: "Matthieu Baerts (NGI0)" , Geliang Tang , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1.y] Revert "mptcp: add needs_id for netlink appending addr" Date: Sun, 12 Apr 2026 16:02:51 -0400 Message-ID: <20260412200251.2405108-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026041225-carry-wolf-ae7e@gregkh> References: <2026041225-carry-wolf-ae7e@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Matthieu Baerts (NGI0)" [ Upstream commit 8e2760eaab778494fc1fa257031e0e1799647f46 ] This commit was originally adding the ability to add MPTCP endpoints with ID 0 by accident. The in-kernel PM, handling MPTCP endpoints at the net namespace level, is not supposed to handle endpoints with such ID, because this ID 0 is reserved to the initial subflow, as mentioned in the MPTCPv1 protocol [1], a per-connection setting. Note that 'ip mptcp endpoint add id 0' stops early with an error, but other tools might still request the in-kernel PM to create MPTCP endpoints with this restricted ID 0. In other words, it was wrong to call the mptcp_pm_has_addr_attr_id helper to check whether the address ID attribute is set: if it was set to 0, a new MPTCP endpoint would be created with ID 0, which is not expected, and might cause various issues later. Fixes: 584f38942626 ("mptcp: add needs_id for netlink appending addr") Cc: stable@vger.kernel.org Link: https://datatracker.ietf.org/doc/html/rfc8684#section-3.2-9 [1] Reviewed-by: Geliang Tang Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260407-net-mptcp-revert-pm-needs-id-v2-1-7a25cbc324f8@kernel.org Signed-off-by: Jakub Kicinski [ applied changes to net/mptcp/pm_netlink.c instead of renamed net/mptcp/pm_kernel.c ] Signed-off-by: Sasha Levin --- net/mptcp/pm_netlink.c | 24 +++++------------------- 1 file changed, 5 insertions(+), 19 deletions(-) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 92ca81a5df675..a16a7a538c425 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1080,7 +1080,7 @@ static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry) static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, struct mptcp_pm_addr_entry *entry, - bool needs_id, bool replace) + bool replace) { struct mptcp_pm_addr_entry *cur, *del_entry = NULL; unsigned int addr_max; @@ -1133,7 +1133,7 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, } } - if (!entry->addr.id && needs_id) { + if (!entry->addr.id) { find_next: entry->addr.id = find_next_zero_bit(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1, @@ -1144,7 +1144,7 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, } } - if (!entry->addr.id && needs_id) + if (!entry->addr.id) goto out; __set_bit(entry->addr.id, pernet->id_bitmap); @@ -1271,7 +1271,7 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc entry->ifindex = 0; entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT; entry->lsk = NULL; - ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true, false); + ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, false); if (ret < 0) kfree(entry); @@ -1513,18 +1513,6 @@ static int mptcp_nl_add_subflow_or_signal_addr(struct net *net, return 0; } -static bool mptcp_pm_has_addr_attr_id(const struct nlattr *attr, - struct genl_info *info) -{ - struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1]; - - if (!nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr, - mptcp_pm_addr_policy, info->extack) && - tb[MPTCP_PM_ADDR_ATTR_ID]) - return true; - return false; -} - static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) { struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; @@ -1566,9 +1554,7 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) goto out_free; } } - ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, - !mptcp_pm_has_addr_attr_id(attr, info), - true); + ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true); if (ret < 0) { GENL_SET_ERR_MSG(info, "too many addresses or duplicate one"); goto out_free; -- 2.53.0