From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E60AA25D8E8; Tue, 11 Mar 2025 15:13:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741706005; cv=none; b=kNZ19Q+fsvDv1XTmzmf/TaUIQL31vaur6pbnei8SI0KdDtRO6ecbx6JmdRgNVv/1prZ+tv04d4TrGJVGCfzdF5rJelKZMrRNW5MyoSK4dlsXzNsFPdy3AAF6BPP1V4Z7Lp9QrRDmrobAn7OPpqeFuAiwyXnY8tH20LaSwXXt0bI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741706005; c=relaxed/simple; bh=QIGNOi28471RkVGiYjmlwldPpkE9sohoTpzAWlU9h1g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BbYS+el9j0+yWrxv/xRwOt6Fe8VlKToNTSUgPqUjDaAANar4zJNpyrDB1kJbjqDIisTk8w3XZ91Z0cDSHwYYdvhtl4tZsXX5fpYNQ0EnwbxmpXMJSBmvUbdfj08jiiyvsAOk8t5IgB/gxCSExMbJwIjxGsq7WDhgEZCuVVqaRAQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FSAGblyx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FSAGblyx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 37EE2C4CEEC; Tue, 11 Mar 2025 15:13:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741706004; bh=QIGNOi28471RkVGiYjmlwldPpkE9sohoTpzAWlU9h1g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FSAGblyxnugtRf/UKDfgHctfiDCMt0KT2TkO4hm+tZ/tsSFFq05kDzgV0ycY/8EsL flyBkBamvYO5VfcPDcRzAhOA5mF6D1nliQcaFHsgMCfTsbMSOvRT2ZiZL2wINZZ1cH 1zKRB4QfIgxgeGZUmh0rsOT82dILiKgLxw8GdZn4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Ahern , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.4 211/328] ndisc: extend RCU protection in ndisc_send_skb() Date: Tue, 11 Mar 2025 15:59:41 +0100 Message-ID: <20250311145723.288825850@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250311145714.865727435@linuxfoundation.org> References: <20250311145714.865727435@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit ed6ae1f325d3c43966ec1b62ac1459e2b8e45640 ] ndisc_send_skb() can be called without RTNL or RCU held. Acquire rcu_read_lock() earlier, so that we can use dev_net_rcu() and avoid a potential UAF. Fixes: 1762f7e88eb3 ("[NETNS][IPV6] ndisc - make socket control per namespace") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250207135841.1948589-8-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/ndisc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 92e35b3096dba..fe10f1ce167be 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -470,16 +470,20 @@ static void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr, const struct in6_addr *saddr) { + struct icmp6hdr *icmp6h = icmp6_hdr(skb); struct dst_entry *dst = skb_dst(skb); - struct net *net = dev_net(skb->dev); - struct sock *sk = net->ipv6.ndisc_sk; struct inet6_dev *idev; + struct net *net; + struct sock *sk; int err; - struct icmp6hdr *icmp6h = icmp6_hdr(skb); u8 type; type = icmp6h->icmp6_type; + rcu_read_lock(); + + net = dev_net_rcu(skb->dev); + sk = net->ipv6.ndisc_sk; if (!dst) { struct flowi6 fl6; int oif = skb->dev->ifindex; @@ -487,6 +491,7 @@ static void ndisc_send_skb(struct sk_buff *skb, icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif); dst = icmp6_dst_alloc(skb->dev, &fl6); if (IS_ERR(dst)) { + rcu_read_unlock(); kfree_skb(skb); return; } @@ -501,7 +506,6 @@ static void ndisc_send_skb(struct sk_buff *skb, ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len); - rcu_read_lock(); idev = __in6_dev_get(dst->dev); IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); -- 2.39.5