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 431311A681D for ; Sun, 12 Apr 2026 22:52:09 +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=1776034329; cv=none; b=gW9KWsVwJGbAJKmqcJgQIu5w2SiNnrrWnEXSc2ze4HOxod7wb8BQqqKj8tn2tG1g++4O2lE8NfxeVHM5M3EP/NFyG5H9srOfwPJPXs/y8rQWbrkfTwWjKOVrCWFtPMc2M5kxGqqAz750x1Ff/a5q/oPuIOHyo6vDy3H3B3ni+9c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776034329; c=relaxed/simple; bh=IksqlCf1NyFFB1DJyYdI09+di7LRU35CFfLW5RUBtAw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FzPiQWy9QkH3QK6J8AObBMter/7WnvwbE63QeM85vthRmwVz9fdW4PdWPBKzZFB7tIDGsxbwv/FvdAeioDvT51KRHGLuyMVOqd4Sv8js83QAZj89TSN/7fMl9WU+lgDup3BdmWQodOizJ6XLW+Ojb/OKFsamZRsoulu+Aw5Xy7g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=s36sQ8BO; 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="s36sQ8BO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 510A1C19424; Sun, 12 Apr 2026 22:52:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776034328; bh=IksqlCf1NyFFB1DJyYdI09+di7LRU35CFfLW5RUBtAw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=s36sQ8BOXLxJ2z5cWjDe0gesjWCG6/24LHaLm6zzNPOUwISw5LzyphSIqwveb680M ZRJ9whgtI8hQsNccl43MDHH2vi6kEzfOSvYLDg0Zu3GF6qD5Mv6f/NlW1gV0NZNI2P 7ZNrXhxc9mPUOsOsxyTMeUnG4pzDU/jDbmpNKEHG3Go/5EcnuuI/uuSxxDGbSSdb03 lEhuUKrU1z/gC/T9PRiUl37LLro5SC31ga/GbQ4TilLaAfO8Kc34sVIc9+pXAlKIYh lPvF2G39IjybptHdIHc8zkhDVU/EmoU2wRjtcMeReUW9z8+So+TZvyGgZ+amBCLuIF T5yfEIj2LQdAQ== From: Sasha Levin To: stable@vger.kernel.org Cc: "Matthieu Baerts (NGI0)" , Geliang Tang , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15.y] Revert "mptcp: add needs_id for netlink appending addr" Date: Sun, 12 Apr 2026 18:52:06 -0400 Message-ID: <20260412225206.2462132-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026041226-animating-improve-ed02@gregkh> References: <2026041226-animating-improve-ed02@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 [ adapted changes from pm_kernel.c to pm_netlink.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 1c8aabce33a6a..8190efa19a595 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -937,8 +937,7 @@ static bool address_use_port(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) + struct mptcp_pm_addr_entry *entry) { struct mptcp_pm_addr_entry *cur; unsigned int addr_max; @@ -965,7 +964,7 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, goto out; } - if (!entry->addr.id && needs_id) { + if (!entry->addr.id) { find_next: entry->addr.id = find_next_zero_bit(pernet->id_bitmap, MAX_ADDR_ID + 1, @@ -976,7 +975,7 @@ 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); @@ -1117,7 +1116,7 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) entry->ifindex = 0; entry->flags = 0; entry->lsk = NULL; - ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true); + ret = mptcp_pm_nl_append_new_local_addr(pernet, entry); if (ret < 0) kfree(entry); @@ -1339,18 +1338,6 @@ 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]; @@ -1377,8 +1364,7 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) return ret; } } - ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, - !mptcp_pm_has_addr_attr_id(attr, info)); + ret = mptcp_pm_nl_append_new_local_addr(pernet, entry); if (ret < 0) { GENL_SET_ERR_MSG(info, "too many addresses or duplicate one"); if (entry->lsk) -- 2.53.0