From patchwork Fri Nov 5 01:49:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Safonov X-Patchwork-Id: 12603945 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20356C43217 for ; Fri, 5 Nov 2021 01:50:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0264D61268 for ; Fri, 5 Nov 2021 01:50:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231848AbhKEBwn (ORCPT ); Thu, 4 Nov 2021 21:52:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231683AbhKEBwk (ORCPT ); Thu, 4 Nov 2021 21:52:40 -0400 Received: from mail-wr1-x42b.google.com (mail-wr1-x42b.google.com [IPv6:2a00:1450:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2ACE9C06120B for ; Thu, 4 Nov 2021 18:50:00 -0700 (PDT) Received: by mail-wr1-x42b.google.com with SMTP id d24so11421602wra.0 for ; Thu, 04 Nov 2021 18:50:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=+ZX3pYJ1I/7ebtQwANMInsRgOc/yS6aTn3F+Fk+PiwA=; b=GsPk6IXOjNs0SPvXxuznhJg1YhpoxbWiSH6pSRXi8P/R0//AeMACHltL4qoPIRMz8P IrFp99b1IUUs5OTWeGsqg4lbJU6kkaOwjhbdS7M42pbe7et5jbVcyfJjSRJEOrwH1AeY yqfRuU3xh5UbfkIRxG3+1JCXO4+6VYi7pu+EE92plfdxuV37Eh9vRsu/AvhaUmyM9R27 Vq1tmG6Vedja2BG0lsHyvSdEoOUZaaiXg2G02JHIWrQaeaW9zL10dRKuD4/SM5moGXGn maJY1f/+RHr5ekxuV7mYJq1dC4Yd5sS6HriL/BBrMrbBWP4y+i0MmG6sgBgINbT0iw9O q4SQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+ZX3pYJ1I/7ebtQwANMInsRgOc/yS6aTn3F+Fk+PiwA=; b=fXCRLSyzLRyQuwlAJ4lD422kIwuUc+fFC3wBF8uzhzwD1EmRrBogj3ULribw5a3YgO zop1gAq7n8aEmVJ7rlauyFbHaDR+tXCBOgNwG0BFileVsjq3uCMDWePMIIPl4JWaqBX8 46Yr/qg2V4gjMkvx9Qw9FFPewUFIAe2wl9JTPX5oEjMcc/i7ckE2kfAqc3ff1xkM+tb1 7SxwvPPpk24oh9SaPlBIi7ahLCQUmL3teVrTkRoiQdIKn9OmZvm+xO4Yt94uepzpheAq Dax5qjgbS75cmwIT03RMURf+Iz+4cZzgHlIYjLRGK8kJlng0jWbrVGKTfxG5Szk+OcJJ VtVQ== X-Gm-Message-State: AOAM5337Q5CgEf1NHTiSLW1ZyeW8bPIZkcmVksz87JOI+FucWP1InILR XMX9P11WdYSN4/2MdZ7BTST9vw== X-Google-Smtp-Source: ABdhPJyTYh3Ig4SsaG9/lmxp6FpLNLdjOI6iWi6OA7zO5KbzwlTFLcjrRe7t+hJwW6ea2dbTESgj3g== X-Received: by 2002:a5d:4107:: with SMTP id l7mr51155903wrp.209.1636076998744; Thu, 04 Nov 2021 18:49:58 -0700 (PDT) Received: from localhost.localdomain ([2a02:8084:e84:2480:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id c6sm7202421wmq.46.2021.11.04.18.49.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Nov 2021 18:49:58 -0700 (PDT) From: Dmitry Safonov To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Dmitry Safonov , Andy Lutomirski , David Ahern , "David S. Miller" , Eric Dumazet , Francesco Ruggeri , Jakub Kicinski , Herbert Xu , Hideaki YOSHIFUJI , Leonard Crestez , linux-crypto@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 3/5] tcp/md5: Alloc tcp_md5sig_pool only in setsockopt() Date: Fri, 5 Nov 2021 01:49:51 +0000 Message-Id: <20211105014953.972946-4-dima@arista.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211105014953.972946-1-dima@arista.com> References: <20211105014953.972946-1-dima@arista.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Besides setsockopt() tcp_md5_do_add() can be called from tcp_v4_syn_recv_sock()/tcp_v6_syn_recv_sock(). If it is called from there, tcp_md5_do_lookup() has succeeded, which means that md5 static key is enabled. Which makes this tcp_alloc_md5sig_pool() call to be nop for any caller, but tcp_v4_parse_md5_keys()/tcp_v6_parse_md5_keys(). tcp_alloc_md5sig_pool() can sleep if tcp_md5sig_pool hasn't been populated, so if anything changes tcp_md5_do_add() may start sleeping in atomic context. Let's leave the check for tcp_md5sig_pool in tcp_md5_do_add(), but intentionally call tcp_alloc_md5sig_pool() only from sleepable setsockopt() syscall context. Signed-off-by: Dmitry Safonov --- net/ipv4/tcp_ipv4.c | 5 ++++- net/ipv6/tcp_ipv6.c | 3 +++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 13d868c43284..6a8ff9ab1cbc 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1190,7 +1190,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO); if (!key) return -ENOMEM; - if (!tcp_alloc_md5sig_pool()) { + if (WARN_ON_ONCE(!tcp_md5sig_pool_ready())) { sock_kfree_s(sk, key, sizeof(*key)); return -ENOMEM; } @@ -1294,6 +1294,9 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname, if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) return -EINVAL; + if (!tcp_alloc_md5sig_pool()) + return -ENOMEM; + return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 2cc9b0e53ad1..3af13bd6fed0 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -654,6 +654,9 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) return -EINVAL; + if (!tcp_alloc_md5sig_pool()) + return -ENOMEM; + if (ipv6_addr_v4mapped(&sin6->sin6_addr)) return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], AF_INET, prefixlen, l3index, flags,