From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 8544137F30C for ; Sat, 17 Oct 2026 03:29:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792207777; cv=none; b=hqDOAXHKAhh+UM7TcDstUNGb/DisBamxYhfiKmwkdmSKSAkZfaJUWQPxf8QGRakW8zZ01e0hTXvyvZlwV6KD4UHTOELhzsNFBc5+gNuUGQ/y27Q/qWHWQN1U4YfE+cJDESnLzZuiF4MacxfTCZf8uJ3lmASF9PkCdYBb0CSirkk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792207777; c=relaxed/simple; bh=2b3wYtFJFTdTUIt1iB9cnF6Bc6fgtRjiwkSSKc++JFQ=; h=Message-ID:From:Subject:To:In-Reply-To:References:Content-Type: Date; b=XcYe70WobTzYEFt7Dmq89rL8Zc7bkv5QjOxYibp1S6NjHdrvEaONz6k4WMnV1yTnY+JQw44ir9uE/MEM7lXS4LzzJTEfJ4Xt5PykTWUWLLb11F2o9ghFgfbdFxX3UWkd7CdHJa0o2WI5BXgqQ6JSxgUPiB9Hn6h3mw6jAkJIUG0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C3zS2s/M; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="C3zS2s/M" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52DEE1F000C6; Sat, 17 Oct 2026 03:29:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792207776; bh=yx2OSCuuo1Q9X+a7AT4p4Udagsc1c7FJLNPSABOredo=; h=From:Subject:Reply-To:To:In-Reply-To:References:Date; b=C3zS2s/MK/sAn2tqkbaT+dDCsvyMFX1R3DK2kVKJuOwxuVNtMt1PkK44mjr6LRnXi G4zKQELjKToAT14y8qGEU97G0AIl0i9xGxrSXDVbRglGZzuHFijWPzrZAJBRXO/K7t pbrsleJopUcWrFi48Sn0+4O++X4667R3KvT98LpFvDA4RifOaY8gihPqJ64s9tt82N DAEDdcVFNnc065iKjFZeNLOcuzVXBl7HggkiOA4itUsGjbvSSfEX9eFqTt5RhqdG+6 gvA56NgcqRPMD6x3NyMkB/Hind9apJBwfBux5UKi/LCdY/6pHkFGsNvlgKsIzL340g U0bGfrjjh4Ymg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH net-next v5 2/2] net/rds: include the scope id in the sendmsg connection cache check Reply-To: sashiko-reviews@lists.linux.dev To: "Allison Henderson" , linux-rdma@vger.kernel.org In-Reply-To: <20261017032358.2563121-3-achender@kernel.org> References: <20261017032358.2563121-1-achender@kernel.org> <20261017032358.2563121-3-achender@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 17 Oct 2026 03:29:36 +0000 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > rds_sendmsg() reuses the connection cached in rs->rs_conn when its > peer address and ToS match the request. The interface index is part > of a connection's identity as well: rds_conn_create_outgoing() passes > the request's scope_id down as dev_if, and rds_conn_lookup() compares > c_dev_if, so sends to the same link-local address through two > interfaces are two different connections. The cache-hit test never > looked at it. >=20 > A socket bound to a non-link-local address has rs_bound_scope_id 0, > and the scope check at the top of rds_sendmsg() accepts any non-zero > destination scope for such a socket. So after a send to fe80::x%ifA, > a send to fe80::x%ifB hits the cached ifA connection and the datagram > leaves through ifA, to whichever peer answers to that address there. >=20 > Compare c_dev_if with the request's scope_id in the cache test, so > that such a send takes the lookup path and finds, or creates, the ifB > connection - the same key the lookup uses. With the previous patch a > send without a destination carries the connected peer's scope, or the > bound scope for a non-link-local peer, which is what an explicit send > to that peer computes, so the comparison is exact for it too. >=20 > Found by inspection while reworking this cache for the connection > lifetime series on net-next; not observed in the field. >=20 > Fixes: 1e2b44e78eea ("rds: Enable RDS IPv6 support") > Assisted-by: Claude-Code:claude-fable-5 > Signed-off-by: Allison Henderson Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261017032358.2563= 121-1-achender@kernel.org?part=3D2