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 D791933032C; Fri, 9 Jan 2026 12:49:20 +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=1767962960; cv=none; b=MbBvK+koQajR/ekS29aJ7RLcqlW1nqtnIXOYNDPywhJOTaytv5iUm/o/KcJ78sGcG7FN14pw+M3vJ/uH6oi3Mb6d0MAgDuuQa9ZP7pYjauBoX6Ptjrk/pSh8yrlqDUwNgDLk4Tl/D+9WOuVjBnu4LA9PMyw5+iiCw0qiQSFmYgA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767962960; c=relaxed/simple; bh=x6qQIB93cZgq9ZcqImbPIuN5JCFirZeAb4lazCO2Gdg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UCUI69UQHTcOLslqK7XDEDn1zFtdIsku5TeVGo8GTDHRxM/VLv/8Zsx3govpY8VMXU7frDR18UoryE2LF1qL+y0GVh7dGpohQ6NluUUFuQv9/jAVfd6G19PkAJkD6KjMpL/qzreQOebz4O67KCyAsTYGZFuL1VHOSNzaBKjnuqk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rANM5kRY; 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="rANM5kRY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63A06C16AAE; Fri, 9 Jan 2026 12:49:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767962960; bh=x6qQIB93cZgq9ZcqImbPIuN5JCFirZeAb4lazCO2Gdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rANM5kRYkKpn6hFKWfo+3b8r1fHbTpHjaG86Df3jiP0cMd81DXfP8xz7UawDMlrXP LoUJVj2w9LsJz9kRdI/OYM++RZUYo4OqRkY+viwKEUqnCGYHPApWqTFbth8N5SPRHr nsfuVCSQEyDA7IAXbJV/iiTk+ClONVmNSVXtY6W0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mat Martineau , "Matthieu Baerts (NGI0)" , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 548/634] mptcp: pm: ignore unknown endpoint flags Date: Fri, 9 Jan 2026 12:43:46 +0100 Message-ID: <20260109112138.211676374@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260109112117.407257400@linuxfoundation.org> References: <20260109112117.407257400@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/mptcp.h | 1 + net/mptcp/pm_netlink.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) --- a/include/uapi/linux/mptcp.h +++ b/include/uapi/linux/mptcp.h @@ -88,6 +88,7 @@ enum { #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) enum { MPTCP_PM_CMD_UNSPEC, --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1424,7 +1424,8 @@ int mptcp_pm_parse_entry(struct nlattr * } 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]));