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 2B3BB30C371; Mon, 13 Apr 2026 16:42:10 +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=1776098531; cv=none; b=l6hoZ+k4pbeR1MGK0aaYdCCGKHONEumtjdflRHsKjb6oH+wFR/xx4IgPZkqea/EZ9E9TmXGgAxHWpbcEXYOzr4BWTqmweY89Ggn0gTwRqeBozCUWlCa2aSH4avbbFjPKtF7TDd+2uSaLEvdNdTqhAH4g/eldapFRDIdmkpc7jDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776098531; c=relaxed/simple; bh=pSpHiebUu3bUEaY72l/GWi0P7sXe4IbT9Z30oJ8oiPU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uO55z0EspnDY7sJ2DBBG3Qkdh686sG6aNSp6sc6cAULdt37h/V7HLuq4nwr5OBGnmG1XVzwXx3umlfWzSJpiSWVslBcIGF3UjHU4ul+SXZZblAigvb3LEiWGgn73eRXFVUA8Yt8ccLBHA2BMB3+0/+mCcqN2ma2ZR4l5RByGSBA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xb6bTPqt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xb6bTPqt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32651C2BCAF; Mon, 13 Apr 2026 16:42:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776098530; bh=pSpHiebUu3bUEaY72l/GWi0P7sXe4IbT9Z30oJ8oiPU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xb6bTPqtULWIpqz+Wxt2ICOM6kzRpcLI3HEd0sVH8rfEuctKZX026goiMR6O+eAYE vu7F3HPI9yDwj+KZ8HctRsX7VCYsDKN+KEVBkL7OnqeY0lmKcnjNfOoEAMfdXCn5Gk Q966te7H4L8/9yL6B1EhNWY7DkDiJFbC8GVq8Tg0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Geliang Tang , "Matthieu Baerts (NGI0)" , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 543/570] Revert "mptcp: add needs_id for netlink appending addr" Date: Mon, 13 Apr 2026 18:01:14 +0200 Message-ID: <20260413155850.786692199@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155830.386096114@linuxfoundation.org> References: <20260413155830.386096114@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: "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 Signed-off-by: Greg Kroah-Hartman --- net/mptcp/pm_netlink.c | 24 +++++------------------- 1 file changed, 5 insertions(+), 19 deletions(-) --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -972,8 +972,7 @@ static bool address_use_port(struct mptc } 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; @@ -1000,7 +999,7 @@ static int mptcp_pm_nl_append_new_local_ 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, @@ -1011,7 +1010,7 @@ find_next: } } - if (!entry->addr.id && needs_id) + if (!entry->addr.id) goto out; __set_bit(entry->addr.id, pernet->id_bitmap); @@ -1152,7 +1151,7 @@ int mptcp_pm_nl_get_local_id(struct mptc 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); @@ -1374,18 +1373,6 @@ next: 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]; @@ -1412,8 +1399,7 @@ static int mptcp_nl_cmd_add_addr(struct 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)