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 B253B1EEA5F for ; Tue, 30 Dec 2025 13:21:13 +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=1767100874; cv=none; b=GuYj/Alb6HsuO7eW+XRMclnxTxEtRyTN702XxTgx1AREHbuRyzn9a0CKvyim9u3wGku3/WlPpiBiYlOJ9QNKPsPj6JF7Jbn3Sv2oze0NG0+oBmwXoQ/ZhALhR2fgG8M/nVtG6cd7/uvFKwJv2VHv+qxxDHyRCzDjFsYquytLkSo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767100874; c=relaxed/simple; bh=zTlD67a2zRRvZej4XaDiVkkCr6Vjmnx5MzZD0QnpXEI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ue/LLgONCLll8YibqDe5Fl/2KAK6dkCPnI90VwK4CIwL6uohmGldC03YG7zunV2/ORDnrN8kIc2xyR//72xOCSSy7fm8JRDJnWVQx4wX/W3opx1C6mb+1izgrpUWRsIdHY2+LUzteDb8k0aDy/w/JIvVSV/AffhSPeHukFYdALw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O8jV/50j; 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="O8jV/50j" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AD47C4CEFB; Tue, 30 Dec 2025 13:21:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767100873; bh=zTlD67a2zRRvZej4XaDiVkkCr6Vjmnx5MzZD0QnpXEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O8jV/50jmcRxIm1JPSKookdBNsBV+QuucMzEz+oALSrps2AYVpDCwtdbWcU7M5H2C iw7gE4tyTJSGzx0D6VxSAYaou6mz5Mbopo8p9lVrbzytPX2ilbJQJsdoJcAvTWIpfh F84G0P8+Vl7OV36U+GJqkzexy7jbg/Kn3YGvQ3IGb+xwjK44A7t5cjfZ9/JFGdWsOk ZRpfviWsp9EwCQxjGwmAtjq9jyL3uxNJvClXZu+3Jlx/iWk81cRkCyzLqlzhuhXVVz cI95uFB9sSRv94r3mewa8VUeEG3LREmi4LnZJPgA8ELI30hPTRpMW9n3edqFOYtDhy BABkmFeYJil7Q== From: Sasha Levin To: stable@vger.kernel.org Cc: "Matthieu Baerts (NGI0)" , Mat Martineau , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12.y] mptcp: pm: ignore unknown endpoint flags Date: Tue, 30 Dec 2025 08:21:11 -0500 Message-ID: <20251230132111.2180152-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025122921-regress-overhand-2900@gregkh> References: <2025122921-regress-overhand-2900@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 0ace3297a7301911e52d8195cb1006414897c859 ] Before this patch, the kernel was saving any flags set by the userspace, even unknown ones. This doesn't cause critical issues because the kernel is only looking at specific ones. But on the other hand, endpoints dumps could tell the userspace some recent flags seem to be supported on older kernel versions. Instead, ignore all unknown flags when parsing them. By doing that, the userspace can continue to set unsupported flags, but it has a way to verify what is supported by the kernel. Note that it sounds better to continue accepting unsupported flags not to change the behaviour, but also that eases things on the userspace side by adding "optional" endpoint types only supported by newer kernel versions without having to deal with the different kernel versions. A note for the backports: there will be conflicts in mptcp.h on older versions not having the mentioned flags, the new line should still be added last, and the '5' needs to be adapted to have the same value as the last entry. Fixes: 01cacb00b35c ("mptcp: add netlink-based PM") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-1-9e4781a6c1b8@kernel.org Signed-off-by: Jakub Kicinski [ GENMASK(5, 0) => GENMASK(4, 0) + context ] Signed-off-by: Sasha Levin --- include/uapi/linux/mptcp.h | 1 + net/mptcp/pm_netlink.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h index 5fd5b4cf75ca..e0fe5160d8bf 100644 --- a/include/uapi/linux/mptcp.h +++ b/include/uapi/linux/mptcp.h @@ -38,6 +38,7 @@ #define MPTCP_PM_ADDR_FLAG_BACKUP (1 << 2) #define MPTCP_PM_ADDR_FLAG_FULLMESH (1 << 3) #define MPTCP_PM_ADDR_FLAG_IMPLICIT (1 << 4) +#define MPTCP_PM_ADDR_FLAGS_MASK GENMASK(4, 0) struct mptcp_info { __u8 mptcpi_subflows; diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 42329ae21c46..0b4ab3c816da 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1409,7 +1409,8 @@ int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info, } if (tb[MPTCP_PM_ADDR_ATTR_FLAGS]) - entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]); + entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]) & + MPTCP_PM_ADDR_FLAGS_MASK; if (tb[MPTCP_PM_ADDR_ATTR_PORT]) entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT])); -- 2.51.0