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 9DBBD3B2D1A; Wed, 30 Sep 2026 19:28:50 +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=1790796531; cv=none; b=uLnqH3DQ0dxoUrSUMchIrdZ65sALoBjYiNAv/Anbxp4hdlWM8Sorsj0Nu/X10uZHljaqK1gBC2Gt6yKWKv7qlABcNGzce3bvnCnhZAD6Ey0tbZfSa/3Pz2QvxL+gfJvKiU7QKAxsVl7LZAF4PaIXj8L4fyWJwGrIbuW05G47ogc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796531; c=relaxed/simple; bh=qrNCTtHkxDNiu7Yybw3IgiyA22FxA2e7cYbqOmqOzDQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f5Ryq4NC54H2aPpeye4RxY1207wqCZUPjKg8ChOTgb+gGPlQVZM09lC44tXpktF6bd0K1ehWtFtUQgzESTHaCCCUDOb3xln0BCgHZ1ISP9vbHiT5zSuiyPXme8nRZ53brHBsFVQE8hs1F9txujPhQf/eFXNCDIdP1c9yhh6P7/A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kIZ9tnZ9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kIZ9tnZ9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 044471F000FF; Wed, 30 Sep 2026 19:28:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790796530; bh=50Va8pIpMstt9XWLwafTheH5F2XmHea2vjCzefLfRkw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kIZ9tnZ9I+EoKCJS6fjge7ZqQzJUQjqXy6w8Uf27Oh80zYMt8PK1B8pSCbrrjLfxm KOoNGQsHjjzn2NTxN7jij5LqBVBkivmYkpSy5U6vilB5w0Rx+gY5bVdwGFp3uwG/nO yFQp3CZp8qg0YcAquiSROt9owwGiLVLqYIauAIkU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kuniyuki Iwashima , Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 0944/1193] ipv6: mcast: Dont hold RTNL for IPV6_DROP_MEMBERSHIP and MCAST_LEAVE_GROUP. Date: Wed, 30 Sep 2026 17:27:08 +0200 Message-ID: <20260930152455.212103284@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kuniyuki Iwashima [ Upstream commit 2ceb71ce7d34e751f91bbca9da3513a2bc29089c ] In __ipv6_sock_mc_drop(), per-socket mld data is protected by lock_sock(), and only __dev_get_by_index() and __in6_dev_get() require RTNL. Let's use dev_get_by_index() and in6_dev_get() and drop RTNL for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP. Note that __ipv6_sock_mc_drop() is factorised to reuse in the next patch. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250702230210.3115355-8-kuni1840@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/ipv6_sockglue.c | 2 -- net/ipv6/mcast.c | 47 +++++++++++++++++++++++----------------- 2 files changed, 27 insertions(+), 22 deletions(-) diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 59965a0decc44..39835f22f3458 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -121,10 +121,8 @@ static bool setsockopt_needs_rtnl(int optname) { switch (optname) { case IPV6_ADDRFORM: - case IPV6_DROP_MEMBERSHIP: case IPV6_JOIN_ANYCAST: case IPV6_LEAVE_ANYCAST: - case MCAST_LEAVE_GROUP: case MCAST_JOIN_SOURCE_GROUP: case MCAST_LEAVE_SOURCE_GROUP: case MCAST_BLOCK_SOURCE: diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index a5d3deef4bb1b..cc0a07f8770d3 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -250,14 +250,36 @@ int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex, /* * socket leave on multicast group */ +static void __ipv6_sock_mc_drop(struct sock *sk, struct ipv6_mc_socklist *mc_lst) +{ + struct net *net = sock_net(sk); + struct net_device *dev; + + dev = dev_get_by_index(net, mc_lst->ifindex); + if (dev) { + struct inet6_dev *idev = in6_dev_get(dev); + + ip6_mc_leave_src(sk, mc_lst, idev); + + if (idev) { + __ipv6_dev_mc_dec(idev, &mc_lst->addr); + in6_dev_put(idev); + } + + dev_put(dev); + } else { + ip6_mc_leave_src(sk, mc_lst, NULL); + } + + atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc); + kfree_rcu(mc_lst, rcu); +} + int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr) { struct ipv6_pinfo *np = inet6_sk(sk); - struct ipv6_mc_socklist *mc_lst; struct ipv6_mc_socklist __rcu **lnk; - struct net *net = sock_net(sk); - - ASSERT_RTNL(); + struct ipv6_mc_socklist *mc_lst; if (!ipv6_addr_is_multicast(addr)) return -EINVAL; @@ -267,23 +289,8 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr) lnk = &mc_lst->next) { if ((ifindex == 0 || mc_lst->ifindex == ifindex) && ipv6_addr_equal(&mc_lst->addr, addr)) { - struct net_device *dev; - *lnk = mc_lst->next; - - dev = __dev_get_by_index(net, mc_lst->ifindex); - if (dev) { - struct inet6_dev *idev = __in6_dev_get(dev); - - ip6_mc_leave_src(sk, mc_lst, idev); - if (idev) - __ipv6_dev_mc_dec(idev, &mc_lst->addr); - } else { - ip6_mc_leave_src(sk, mc_lst, NULL); - } - - atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc); - kfree_rcu(mc_lst, rcu); + __ipv6_sock_mc_drop(sk, mc_lst); return 0; } } -- 2.53.0