From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 74D563B0AC2 for ; Fri, 10 Apr 2026 21:17:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775855862; cv=none; b=Oe8LBr4rJatJm3vlaS+isM/CTAhMOYeBz7VntdmJMiKyFYPfO5ECVm6jDMtnjEqdf4mcpJbtBrsXbBD9MMc0qLrv0ZM1UrUAvUbxlqR0zetjzSqH318geBU3MLpVt8Bt9jgbw9VBqk7m5O8n8zVx7K/mXnb/G2KCKpOfto2uH9w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775855862; c=relaxed/simple; bh=WuWdR6IInU3e6QvkbIiIbPtAjPON4DLLr7yA/g7NPwA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=H7QgMVfbNQwHqqS+AnxqNTWB8oQPrX/FZr36GuDAP1rKEhvyFXslhg/il2Wc+DWLA736rZYAoZwb5V1c/URrs0rilx3YxRRxrwb18HUe8SmT8+pOsoxdIBfFm2S46AMN1/L83hm4DwF5bGMsmawSTgTcF30M7G/K/wl+Sfzi1As= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=vKzpK4PW; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vKzpK4PW" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2b24a00d12cso24580715ad.1 for ; Fri, 10 Apr 2026 14:17:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1775855861; x=1776460661; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=BnG5Bw5JDOJWW1r1TsrbKJx/9qkZ/mmYpnYxcLRvs3I=; b=vKzpK4PWElrqRd30DomCgUoGAKCh4Ln42EmpFQbtydynT9KC2bL5JgI8j9REjJY8++ 5iHWN9mhMBEoT6xGh36RtkxcleqTEmLOR3OGMhNXGrTcmXOvL6jH65fdcwWGOtf7Wqr3 BIQPTqXd+iPWZokfPXXv5QxmAt0lgKxJnNR/h0gfUjgRQJnxDW2Z8oUJVCbU6jx/JWMW 7x/ezIP+zoKfGEzAM60vD+eWYHOsKkxuX/O0ofd/MA+ixJc8wG7lub5+IwFOlMdaGTLG H0fcn6RVB82zH8pMjRMUNS7dX33YC61YpBwS5/S7zFvJTDxgCJb4vH2oRgN3yuWW6SIz D9Dg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775855861; x=1776460661; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=BnG5Bw5JDOJWW1r1TsrbKJx/9qkZ/mmYpnYxcLRvs3I=; b=c3pFY+vX2zeCwlzvv4AMVaG3iAa2rWtKVGYIAk8ww14HBNNZU847fwrN3HUSqxshRi UbJDvr7bQ7AeidIUBCgOJ9KE1Lvss//oNSSr+BEseEbqB2ZV+Tx7Y/5bnIK66hqHtjWb TfDlVsbZ/eNnyQTLtv6AtI8wxK2HjlwDP08NKBbz4hXexCAya7JihwRgn1ggXcPeuXhm Y/4zdKGbKsuCHHp0Y12+TiXLxpKjip/tHjnWoXrCKGWkUgsGfmm7tX4ZwVTlxTGB11iF cjAzvJOqMRBIrkasjlrbvVl9gdmeQ4mACykGaMYjycclSWIwFgrTejPnhcmnDyoRcx6t fFFg== X-Forwarded-Encrypted: i=1; AJvYcCUjsD4c9qgFwrnIWzJWx1JGXIIUJHbfv9KCblOLLBF2hw4tCiQlNIz+2f0ssAydUqztnxBRbMo=@vger.kernel.org X-Gm-Message-State: AOJu0YyAv1+WTOFszsp0nJQlnTToL6NQBK2wa9ecNQEBPLw3EQhokZwl dy0XuC2UwHnU96pdCALPdL2iC15mg82L8NL9gnIc0RjYgC2tDKnKzsRMuzxjWiSgArPh8s6ziit s94cSVw== X-Received: from pgbcp10.prod.google.com ([2002:a05:6a02:400a:b0:c79:165b:33b]) (user=kuniyu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:9153:b0:39f:21a8:1e1d with SMTP id adf61e73a8af0-39fe3c65d84mr5754126637.10.1775855860665; Fri, 10 Apr 2026 14:17:40 -0700 (PDT) Date: Fri, 10 Apr 2026 21:17:01 +0000 In-Reply-To: <20260410211726.1668756-1-kuniyu@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260410211726.1668756-1-kuniyu@google.com> X-Mailer: git-send-email 2.53.0.1213.gd9a14994de-goog Message-ID: <20260410211726.1668756-6-kuniyu@google.com> Subject: [PATCH v2 net-next 05/15] ip6mr: Convert ip6mr_rtm_getroute() to RCU. From: Kuniyuki Iwashima To: "David S . Miller" , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Kuniyuki Iwashima , Kuniyuki Iwashima , netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" ip6mr_rtm_getroute() calls __ip6mr_get_table(), ip6mr_cache_find(), and ip6mr_fill_mroute(). Once created, struct mr_table is not freed until netns dismantle, so it's safe under RCU. ip6mr_cache_find() iterates mrt->mfc_hash with rhl_for_each_entry_rcu(). struct mr_mfc is freed with call_rcu(), so this is also safe under RCU. ip6mr_fill_mroute() calls mr_fill_mroute(), which properly uses RCU helpers. Let's call them under RCU and register ip6mr_rtm_getroute() with RTNL_FLAG_DOIT_UNLOCKED. Signed-off-by: Kuniyuki Iwashima --- net/ipv6/ip6mr.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 5356957bfe94..0054db00fadf 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -1388,7 +1388,8 @@ static struct pernet_operations ip6mr_net_ops = { static const struct rtnl_msg_handler ip6mr_rtnl_msg_handlers[] __initconst_or_module = { {.owner = THIS_MODULE, .protocol = RTNL_FAMILY_IP6MR, .msgtype = RTM_GETROUTE, - .doit = ip6mr_rtm_getroute, .dumpit = ip6mr_rtm_dumproute}, + .doit = ip6mr_rtm_getroute, .dumpit = ip6mr_rtm_dumproute, + .flags = RTNL_FLAG_DOIT_UNLOCKED}, }; int __init ip6_mr_init(void) @@ -2712,6 +2713,8 @@ static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, grp = nla_get_in6_addr(tb[RTA_DST]); tableid = nla_get_u32_default(tb[RTA_TABLE], 0); + rcu_read_lock(); + mrt = __ip6mr_get_table(net, tableid ?: RT_TABLE_DEFAULT); if (!mrt) { NL_SET_ERR_MSG_MOD(extack, "MR table does not exist"); @@ -2719,10 +2722,7 @@ static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, goto err; } - /* entries are added/deleted only under RTNL */ - rcu_read_lock(); cache = ip6mr_cache_find(mrt, &src, &grp); - rcu_read_unlock(); if (!cache) { NL_SET_ERR_MSG_MOD(extack, "MR cache entry not found"); err = -ENOENT; @@ -2734,9 +2734,12 @@ static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, if (err < 0) goto err; + rcu_read_unlock(); + return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); err: + rcu_read_unlock(); kfree_skb(skb); return err; } -- 2.53.0.1213.gd9a14994de-goog