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 C1A3D471268; Thu, 17 Sep 2026 07:40:00 +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=1789630802; cv=none; b=H1qvYcmd1Ixj6Q3OSo2GMGp/MxQHln4rbY+lzahgTgJDdK1qd+OJ+WmiBYCz/Q+Btp+NG35sqG9V4x/R81AizQPl/f/MW9Tjydd83m8Hin+nE01vL59SZgDlHJDvTfCe8b9Rp3mCtX2mQEXdh/fIGmypC8dj8B5kAfNp/GzR3P0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789630802; c=relaxed/simple; bh=l09qwOE5YR2ATkzO5c6FnO90asYtEnnucV6slikfzEI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=EiDAVVaeRtxwU/PmyFouaYIKpo3W07HXJFafDla7BX8emrXkPr2ZGxbyObsujuQUBnjMUvUi4hx7TnVIbrmEp0sa7tNEG3XyHOO9nrQAMIoHog7F7fbJnm0pdfEJx9GvvDORKh6ZUIWB864Et2ep+juybU1CDXFAGpDOerLRua8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lofsNwQi; 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="lofsNwQi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E76081F0089A; Thu, 17 Sep 2026 07:39:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789630800; bh=YU42TL81YFZm7tgZvg285pKw+JqqFh9iFlBlrADUa8Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lofsNwQiOMWe1eLLVriQBDKgKKWiX7s0Tab312adN0v5Z5uc6RewzgnBFwhLy1Ikd HVYwjtJXajHSpA99G2n6KwQwR9V8uw+TewbkbBN+/RaxEVj+oMg+D5sy/WMVqFgzoZ /2phl1UGv7W5Jp4BO6TYro/YkzAS/BoRa1kTI0pRG2/z8TvOQ/g2TBWbg4Wa+dNaHi J9zA1QsjTkjJSigKkDuJwjVC/g+pnbtKiB3eLHd/6d0IbZasx8iMNUL5ZtTVTy/xlc VDjFkMFpiOPLHkv0p9jchToggdKHsIIXfuBrQXPuoTzb9bk/2UfMlGMMZw+1dY5LBR ejir5VIXUx1Vw== From: Allison Henderson To: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, pabeni@redhat.com, edumazet@google.com, kuba@kernel.org, horms@kernel.org Cc: achender@kernel.org, nicoyip.dev@gmail.com Subject: [PATCH net-next v4 02/12] net/rds: free every path's transport data on the passive create paths Date: Thu, 17 Sep 2026 00:39:48 -0700 Message-Id: <20260917073958.174056-3-achender@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260917073958.174056-1-achender@kernel.org> References: <20260917073958.174056-1-achender@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit trans->conn_alloc() may allocate transport data for every path of a multipath connection - rds_tcp_conn_alloc() does - which is why the lost-creation-race exit of __rds_conn_create() loops over all npaths when it frees the connection it just built. The passive-connection exit right above it, taken when a loopback parent already has its c_passive twin, frees only path 0 and leaks the transport data of paths 1..npaths-1. RDS/TCP loopback is exactly a multipath passive connection, so this is reachable. Move the loop into a helper and use it on both exits. Fixes: 1c5113cf796b ("RDS: Initialize all RDS_MPATH_WORKERS in __rds_conn_create") Assisted-by: Claude-Code:claude-fable-5 Signed-off-by: Allison Henderson --- net/rds/connection.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/net/rds/connection.c b/net/rds/connection.c index b6c4beb50eaf..a96569a3ee9a 100644 --- a/net/rds/connection.c +++ b/net/rds/connection.c @@ -161,6 +161,22 @@ static void __rds_conn_path_init(struct rds_connection *conn, cp->cp_flags = 0; } +/* Undo trans->conn_alloc(): it may have allocated transport data for + * every path of a multipath connection, not just for path 0. + */ +static void rds_conn_free_transport_data(struct rds_connection *conn, + int npaths) +{ + struct rds_conn_path *cp; + int i; + + for (i = 0; i < npaths; i++) { + cp = &conn->c_path[i]; + if (cp->cp_transport_data) + conn->c_trans->conn_free(cp->cp_transport_data); + } +} + /* * There is only every one 'conn' for a given pair of addresses in the * system at a time. They contain messages to be retransmitted and so @@ -316,7 +332,7 @@ static struct rds_connection *__rds_conn_create(struct net *net, if (parent) { /* Creating passive conn */ if (parent->c_passive) { - trans->conn_free(conn->c_path[0].cp_transport_data); + rds_conn_free_transport_data(conn, npaths); free_cp = conn->c_path; kmem_cache_free(rds_conn_slab, conn); conn = parent->c_passive; @@ -332,18 +348,7 @@ static struct rds_connection *__rds_conn_create(struct net *net, found = rds_conn_lookup(net, head, laddr, faddr, trans, tos, dev_if); if (found) { - struct rds_conn_path *cp; - int i; - - for (i = 0; i < npaths; i++) { - cp = &conn->c_path[i]; - /* The ->conn_alloc invocation may have - * allocated resource for all paths, so all - * of them may have to be freed here. - */ - if (cp->cp_transport_data) - trans->conn_free(cp->cp_transport_data); - } + rds_conn_free_transport_data(conn, npaths); free_cp = conn->c_path; kmem_cache_free(rds_conn_slab, conn); conn = found; -- 2.25.1