From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (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 0438F263F4A for ; Thu, 4 Jun 2026 22:47:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780613243; cv=none; b=H9wFbEOmiI4qzVObqHjL6Gx/k0qpefch136c2lxjPSHth6SJy0jXAkHg/y/+9bAwdnjSujBn6w6umV1DSMeHOQkYZkdk9kmk7qkORq1B3hGXMLLnn07taEdtwGvFtX68rDvwxVIjcA+sYM1DS6yrcgZg1wwKJAhJxsGA8nf6NNM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780613243; c=relaxed/simple; bh=CrhcH43a/gYR+2K6n4AM8+cnEshLKKK2gvXOmlI2APA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=RqvSpKU3yx0m/49X8mGVN229tFKzCka5+9DZpcrmw3P0iG05/E4lUu62D1sz/J1WaIOKMduWqVrHavHFk9LK5N+uZ3pKYM264o1sm9v4Hre0OhwMpevfSqv2kEB9avjhy+d/bk0trMM66Uw9ZlWrVPh/f1xDjrAPnvQmISYp/VA= 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=GCLzkc7J; arc=none smtp.client-ip=209.85.210.202 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="GCLzkc7J" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-842b0dd8107so117939b3a.0 for ; Thu, 04 Jun 2026 15:47:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1780613241; x=1781218041; 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=LljQoMsrT+rI6NbScCYdrsaU31SJSEc6KDPiyq+eTCY=; b=GCLzkc7J6EXnBkPbxugp/PPFxoRKoyrk4sa+dQGHXLBETALukd/b2otGqr/+zcu9xg z7wdhLIvbqjkmFybKifB2r84ffFbezKYi2+wcCZWjwQUaCNLnmpI5+qy6RFCJJRnxxOi 5C+Gx1jbSZjJtvkVygFCBbeuZeKfkYTta2e/u9f+NuLfPAWrtploG97JUBZ3TCbZAPDT mXjHoqjIUDoJ/p4jSyhOeUprk3hlNb1R8Brig5AiBBVy+u3YNYnEDWX0WsYdZ47GYru8 ih7wyuNJ7Xk8Bd7ypQTVvc4MtCFgVwDCLmI/v6hr48MeMpKnL+XZXC9BHENGmfFuDSlb P2NQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780613241; x=1781218041; 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=LljQoMsrT+rI6NbScCYdrsaU31SJSEc6KDPiyq+eTCY=; b=A1ImI3l8ut51dwabA8cEOb+sTuWp83yW5wjQCVCQYYMZY5dL0pP4P64105hTAblOn/ fSDJDFW8hKpmt73GiY2y3BX9KlgNu3Cp60U6d+9mjDbxCGllSbL2vwb+zg0o6qL3YrC4 S7GA/UOLEcDVMDx752UJ+3IfdYkoza8vFbibg0Jq6kwK16IH3Pcy3LpliGbTYgqCeli/ cWImoSJu7I+4GMIzy+/Bnc80VBJ8JVc7s50rz/8T3O9NIR9R86xZpfjwEGyH6bDxY+Fs wVAQ8Lppfv8MHX3ZGNujH/gqY5aQ4tWb/L5KBWt6nxMtCOC39RrpVv5JUv9BbfmNrNNc +ayg== X-Forwarded-Encrypted: i=1; AFNElJ/A7n+N4i9LVfZR1FUggL/twjRjbFjeKydYsPnpzGGfevys4Qk6VyfLe9I+DkFvdeLi7PpPkI4=@vger.kernel.org X-Gm-Message-State: AOJu0YxOaCzb+jq1q9gR//xbKtYgt2+fZ/OT8mzqh/frd6WSp4x6kbOU vpnCF3EkLToCfnuhYw3tE40IlKc9YicaskXi9ul/4S4/o0uqRoTnxitqVSW9tI+i93YGKcXrNRy Rv4BtyA== X-Received: from pfbiv2.prod.google.com ([2002:a05:6a00:66c2:b0:842:6be9:dfb1]) (user=kuniyu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:bb0f:b0:842:79f5:8325 with SMTP id d2e1a72fcca58-842b0ffc873mr640503b3a.44.1780613241015; Thu, 04 Jun 2026 15:47:21 -0700 (PDT) Date: Thu, 4 Jun 2026 22:46:23 +0000 In-Reply-To: <20260604224712.3209821-1-kuniyu@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260604224712.3209821-1-kuniyu@google.com> X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog Message-ID: <20260604224712.3209821-6-kuniyu@google.com> Subject: [PATCH v3 net-next 05/15] ip6mr: Convert ip6mr_rtm_getroute() to RCU. From: Kuniyuki Iwashima To: "David S . Miller" , David Ahern , Eric Dumazet , Ido Schimmel , 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 018985593b03..51ba22f59506 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -1386,7 +1386,8 @@ 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) @@ -2710,6 +2711,8 @@ 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"); @@ -2717,10 +2720,7 @@ 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; @@ -2732,9 +2732,12 @@ 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; } -- 2.54.0.1032.g2f8565e1d1-goog