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 C519C23C4F4 for ; Tue, 30 Dec 2025 13:42:09 +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=1767102130; cv=none; b=MhYXuc6E503TvRII5v+ai2gVsOfGyShW8T9+mVR5QclQDZzRDg6dLI+1RvKPsjAKrNlNN+IYVaiIzuQz7nxpHkVuBmXlETKK5VeZw1/RNDnAwG84UKyQ4j5mPl9DpN3FNkfSBa492XUFqasHWrqv/AukYgGZQhUX4j4+7F2AuAA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767102130; c=relaxed/simple; bh=PGbcrtxVEFaTUEg/sG4CZwz6iF2e/8hwjetHIw+qMh4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RbDfJxdxpwFtrqEmf5bXHh+drBsy1W5WsXGyspnkrBSL80jIC/ayuls721rTkPqC4TgB0nR8JH4/V0RwlTLIWFTc7mXwjDOxivasM/+4DbOXPUPKBvlY9h33aSWuQ/+nK8TZCkj31lpfJcZEv0vyLyj8+sWCOLgNw+XNYg1tzhI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aU1Sri4P; 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="aU1Sri4P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83381C116C6; Tue, 30 Dec 2025 13:42:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767102129; bh=PGbcrtxVEFaTUEg/sG4CZwz6iF2e/8hwjetHIw+qMh4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aU1Sri4Pm8JdSEfSZhCEpPBZV3XIwBgjubiqoZUSkwdltHJ95FmHnL1xkyk5RnIPN Rb+UPXnc1VTBtfyhW+e359MhzgN766NLYAPXCPaqVe2yN4fTTLLS2cpvrzN9e24gIp JnLE8IgiAdN5bWg7VXopGXIPM8wUB6CcCUP+9sp+S6tl+ZoDjYGt87NuTbGBCp9QAb TJIHG6QQuh9lsEm3yMfFTKZPrMENo795K6SRkMWLVJb1SyX047KiFFcu5GD41aVwmQ uy+07nI0HqTUTztgGLQCNGr36Gpn4cNeWpAjwwCvYIaLePPWFVo0KvFyKBRIrKTutR jS8yIX9/fr5Ig== From: Sasha Levin To: stable@vger.kernel.org Cc: "Matthieu Baerts (NGI0)" , Mat Martineau , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6.y] mptcp: pm: ignore unknown endpoint flags Date: Tue, 30 Dec 2025 08:42:06 -0500 Message-ID: <20251230134206.2207988-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025122922-cedar-reapply-f9d1@gregkh> References: <2025122922-cedar-reapply-f9d1@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 00d622121673..926d5de5fd21 100644 --- 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, diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 8dbe826555d2..9f25cfd96f98 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1435,7 +1435,8 @@ 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