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 E166D36494B for ; Sun, 12 Apr 2026 12:54:53 +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=1775998494; cv=none; b=BF/Uti9XKiiFE4D2Yy+GwWeCEkBLe4+pFOCareDLF9c4f2avVQQPb4OGpk0ami6onUSe1SfKIPJGNjX3mmobtxHOrgAh9PpVarjc8ySA8w5UiLmeenWLrVknYZXKdw2iijsbrHhva+mJNOGKAx1wCNzZ8IXRP+anqld6L3vI4Wo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775998494; c=relaxed/simple; bh=orY2Y2pMo9fEFOHWcMYw2aGtcGDN0MueBeDwf36Kzns=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f/x/w2fEkVl6rqoRT2XuvGR3P2VbJNtBuHezc+D0gt/UYFPYSyICJdG2NR3EppDfpcFgtpknlKAPCsWJaFX37J4E/2ilecHu0pwSxAR/HBow5EhlK13jK/8cedzSHlNBFYBFfcaktPsvxnn411cef6jQlyKcM5EeRaljquajZ78= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PyFP2Qa5; 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="PyFP2Qa5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5B0BC19424; Sun, 12 Apr 2026 12:54:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775998493; bh=orY2Y2pMo9fEFOHWcMYw2aGtcGDN0MueBeDwf36Kzns=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PyFP2Qa5MD+fmk/KT2I7jJ0oBgKy+Fd6cicBe129dR4K7BL5Y3KU9520/d9obH+iA bPpZjSARKbA73FL4IN3TDHlUezWU6apyIM00UzVQhFQDY62e53ls7EsJWXgIed2z/E TxNb40K7RIbKum/0o8dUE0phhLu/I/Nb9B8ILbF20zX1dyq5i1WXjyeRi993/+0dJr bkAjc+EzWeow4SagRq4XCGXk8bBit89DOITLA0gKqVP4CgRY9f05f6QKOlFgh9JvGh efJ0ZCdVCTQ1/ybtvRMc6picpMwnsNvZ2SI+5BeaYUZ1Lr2uKs1VExuvkL233aYLCg 8n6ZmzwOYLV7Q== From: Sasha Levin To: stable@vger.kernel.org Cc: "Matthieu Baerts (NGI0)" , Geliang Tang , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12.y] Revert "mptcp: add needs_id for netlink appending addr" Date: Sun, 12 Apr 2026 08:54:51 -0400 Message-ID: <20260412125451.2218427-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026041224-maggot-dallying-8241@gregkh> References: <2026041224-maggot-dallying-8241@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 38e17f2f15d0f..3ac09bfe6e4b2 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1076,7 +1076,7 @@ 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; @@ -1135,7 +1135,7 @@ 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, @@ -1146,7 +1146,7 @@ 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); @@ -1279,7 +1279,7 @@ 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); @@ -1498,18 +1498,6 @@ 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_address_nl_policy, info->extack) && - tb[MPTCP_PM_ADDR_ATTR_ID]) - return true; - return false; -} - int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info) { struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR]; @@ -1551,9 +1539,7 @@ int mptcp_pm_nl_add_addr_doit(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_FMT(info, "too many addresses or duplicate one: %d", ret); goto out_free; -- 2.53.0