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 9A09237AA8E for ; Thu, 26 Feb 2026 02:37:05 +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=1772073426; cv=none; b=ogpNq/l+omtI2S1VXADmeNcPljtvCaVvw9O/jxil+WLswQg22yg+A+Isp1hHfSIWDYQUGTvz79/UONLvaWW8ZxVmkgrrQAjbf8pHLppDiWNjkCk6Wk74adVml7FkWOqguguBRYp0Udv9d+EER7eB5SS9qmFimAYfJhPtvPfqcJU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772073426; c=relaxed/simple; bh=hlpSktstOeW41xrgEbK+uL9ER9JUynqqfZZrg4uMin0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GiE0OCovWNXZP5N5Tovv6Lmp88+EXTFN7vxcckdI5S8Pl9+iOrLNZmMivaWENnTahMTrRt7MXromNfJutoPuIT66aPPwiOx3v6yHQyMCmHFeqpxTWfhMQ2A7VFd2jMIfbgIIbKZ1NHW9SqJD5L6OBINaNPNH+RV/ckJwwemnclk= 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=TGAIdQWA; 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="TGAIdQWA" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-8273f4ed107so32512b3a.2 for ; Wed, 25 Feb 2026 18:37:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772073425; x=1772678225; 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=lAwQolxfnVAZq2X52qB2srTMe0f7C7puDkbiJ3SzKVI=; b=TGAIdQWAoO8kwd8/7ZKwp/7LoN+m/ggn16CDrtMSy9CWFVu6EiIDW3uyClqCivnW5v 23rUPi8s40JO7P/odGIzs03+fHXkraZYm8WfIcgn9orut3UnPKh4UgA5IjuV/hWJA8xY vu8D8GkrBrWJjWI/ny8wyiu61vsuMoZ/GdAl41ng9TEuq85630IO9J14wR2t+bD1Ecqz IOaAPky8a6WqDxDCoajW3gUAd4yhDOgJ3xn3vBHSsueQsPYUW2Dvz+ADHnyR5M+twBIR NFAMcuFDgN7LyE8GNmhz6bfpSCH9vB/2UEhCJO9WPFd3ZKcVNwzh5zq0fi2dnaM7IXcI TN5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772073425; x=1772678225; 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=lAwQolxfnVAZq2X52qB2srTMe0f7C7puDkbiJ3SzKVI=; b=UO/WX7WEJGnAMsEYIXoQ0eQMOU8t1gEQEsWmW1sCFCd7R+yQC8H780nG6ccb0UD5M3 Q0gPwRWiKAZ0Ta/iW2r8x+rZPX2RuO/HPvaBvY+tthRB46ZiGuKRXZQhBPXj8Pjoxu2S q9QMW6Qtkrt4EPfi3NCA9pN+hLMaaVm3FZrt1lNLKFeUt5pJKvZw0/F7lEMBrusV69OT fjNF5cJEI23ryAYYy3RrqgFjaYvjx3uDeNNP7vigSJKL5JcOuML/1JC6NUn16G5xXmKO Awz5OPX2S3ElUZF6V5fiQR8LvGdd++oINQ7u7cH0NmUkj2BUzU7AVC/WnhMJ6TpBH/UJ uwfA== X-Forwarded-Encrypted: i=1; AJvYcCXm6Ps6JDC4a+G3BTmirIGRK/tQj4qoqfIClrT6kO1a3EoMYNWTw2MduMZyo3fJvwsRu1qYESc=@vger.kernel.org X-Gm-Message-State: AOJu0YygIocLNAWWSA5Wu0VAaodLTU2mUScd8I+Xk0vBZ5VX5hwuwuw1 hqKc1t64Q9ENWhvXLRZu9UagaOpTEW23ZZ8hpTNWO7//d7VgK8nNBSsLHP2WnZlfGfiANxkht/9 nOuD7fw== X-Received: from pgag24.prod.google.com ([2002:a05:6a02:2f18:b0:c70:e705:e5cd]) (user=kuniyu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:bd93:b0:824:15ff:d35c with SMTP id d2e1a72fcca58-827338c21damr2209928b3a.63.1772073424558; Wed, 25 Feb 2026 18:37:04 -0800 (PST) Date: Thu, 26 Feb 2026 02:35:27 +0000 In-Reply-To: <20260226023637.1335854-1-kuniyu@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260226023637.1335854-1-kuniyu@google.com> X-Mailer: git-send-email 2.53.0.414.gf7e9f6c205-goog Message-ID: <20260226023637.1335854-16-kuniyu@google.com> Subject: [PATCH v1 net-next 15/15] ipmr: Don't hold RTNL for ipmr_rtm_route(). 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" ipmr_mfc_add() and ipmr_mfc_delete() are already protected by a dedicated mutex. rtm_to_ipmr_mfcc() calls __ipmr_get_table(), __dev_get_by_index(), amd ipmr_find_vif(). Once __dev_get_by_index() is converted to dev_get_by_index_rcu(), we can move the other two functions under that same RCU section and drop RTNL for ipmr_rtm_route(). Let's do that conversion and drop ASSERT_RTNL() in mr_call_mfc_notifiers(). Signed-off-by: Kuniyuki Iwashima --- include/linux/mroute_base.h | 1 - net/ipv4/ipmr.c | 34 +++++++++++++++++++++------------- 2 files changed, 21 insertions(+), 14 deletions(-) diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h index 0baa6f994da9..cf3374580f74 100644 --- a/include/linux/mroute_base.h +++ b/include/linux/mroute_base.h @@ -208,7 +208,6 @@ static inline int mr_call_mfc_notifiers(struct net *net, .tb_id = tb_id }; - ASSERT_RTNL(); atomic_inc(ipmr_seq); return call_fib_notifiers(net, event_type, &info.info); } diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 0dd7d088de50..4e645a87dc6c 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1209,7 +1209,6 @@ static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent) struct net *net = read_pnet(&mrt->net); struct mfc_cache *c; - /* The entries are added/deleted only under RTNL */ rcu_read_lock(); c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr, mfc->mfcc_mcastgrp.s_addr, parent); @@ -1236,7 +1235,6 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt, if (mfc->mfcc_parent >= MAXVIFS) return -ENFILE; - /* The entries are added/deleted only under RTNL */ rcu_read_lock(); c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr, mfc->mfcc_mcastgrp.s_addr, parent); @@ -2851,10 +2849,10 @@ static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh, { struct net_device *dev = NULL; u32 tblid = RT_TABLE_DEFAULT; + int ret, rem, iif = 0; struct mr_table *mrt; struct nlattr *attr; struct rtmsg *rtm; - int ret, rem; ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, rtm_ipmr_policy, extack); @@ -2881,11 +2879,7 @@ static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh, mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr); break; case RTA_IIF: - dev = __dev_get_by_index(net, nla_get_u32(attr)); - if (!dev) { - ret = -ENODEV; - goto out; - } + iif = nla_get_u32(attr); break; case RTA_MULTIPATH: if (ipmr_nla_get_ttls(attr, mfcc) < 0) { @@ -2901,16 +2895,30 @@ static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh, break; } } + + rcu_read_lock(); + mrt = __ipmr_get_table(net, tblid); if (!mrt) { ret = -ENOENT; - goto out; + goto unlock; } + + if (iif) { + dev = dev_get_by_index_rcu(net, iif); + if (!dev) { + ret = -ENODEV; + goto unlock; + } + + mfcc->mfcc_parent = ipmr_find_vif(mrt, dev); + } + *mrtret = mrt; *mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0; - if (dev) - mfcc->mfcc_parent = ipmr_find_vif(mrt, dev); +unlock: + rcu_read_unlock(); out: return ret; } @@ -3341,9 +3349,9 @@ static const struct rtnl_msg_handler ipmr_rtnl_msg_handlers[] __initconst = { {.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_GETLINK, .dumpit = ipmr_rtm_dumplink, .flags = RTNL_FLAG_DUMP_UNLOCKED}, {.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_NEWROUTE, - .doit = ipmr_rtm_route}, + .doit = ipmr_rtm_route, .flags = RTNL_FLAG_DOIT_UNLOCKED}, {.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_DELROUTE, - .doit = ipmr_rtm_route}, + .doit = ipmr_rtm_route, .flags = RTNL_FLAG_DOIT_UNLOCKED}, {.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_GETROUTE, .doit = ipmr_rtm_getroute, .dumpit = ipmr_rtm_dumproute, .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED}, -- 2.53.0.414.gf7e9f6c205-goog