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 4011625D8E8; Tue, 11 Mar 2025 15:13:16 +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=1741705996; cv=none; b=JXeyixa6TVArCqoUCjR9AWgXmj3vliMYEzzczIbovekmHf9BkVEZUlD9fDepEiT0LOTurHF5B1jeR8WpUqivvNN+DQLvojLTXP2OrRoohOlk+3anNuyEALtpuGazPFmSIJTkDr4tXYodH8Cv++TW47PHNITqZOLrueq8TBZAVpw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741705996; c=relaxed/simple; bh=g5Jjznzo9kUU2KCAi7/I9qNO+HicE7BPV8dxZBc2Mks=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fXh6SOrgnE8ZPziGrmH3Vh6/kdeJA24W57Q1rzudnefExHhPyAaH+SGNkZARJCionIKtoDg+Vse1TIa6LgfC8HTFHuodK9XaxE9WZFHJHV0RFzdSPgk31becEVi6KPmeTKOp35e0I54Jgjuyj9iFyDNPUupxMDjMKBJ4tkALxHk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0Y5SQZdQ; 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="0Y5SQZdQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA60BC4CEE9; Tue, 11 Mar 2025 15:13:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741705996; bh=g5Jjznzo9kUU2KCAi7/I9qNO+HicE7BPV8dxZBc2Mks=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0Y5SQZdQmAaIYBjLGlBE0qtJsGeztqa27Ds08UUx/EJM86zy137ZQDwvdY1tne+kf vnYUoymQ2QzjuUwaasenmgnID60ZkufNrj6MYSHHalcSaWIydZcTApwwgb7Y1fUDmV fkBmJtxJVAbeVVV2UBJ1v7nLu8kTj73X84A1B/eY= 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 5.4 208/328] neighbour: use RCU protection in __neigh_notify() Date: Tue, 11 Mar 2025 15:59:38 +0100 Message-ID: <20250311145723.172293580@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 becbd5850c03ed33b232083dd66c6e38c0c0e569 ] __neigh_notify() can be called without RTNL or RCU protection. Use RCU protection to avoid potential UAF. Fixes: 426b5303eb43 ("[NETNS]: Modify the neighbour table code so it handles multiple network namespaces") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250207135841.1948589-4-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/neighbour.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 3e007cbadb707..7ef3630ea20d7 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -3364,10 +3364,12 @@ static const struct seq_operations neigh_stat_seq_ops = { static void __neigh_notify(struct neighbour *n, int type, int flags, u32 pid) { - struct net *net = dev_net(n->dev); struct sk_buff *skb; int err = -ENOBUFS; + struct net *net; + rcu_read_lock(); + net = dev_net_rcu(n->dev); skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC); if (skb == NULL) goto errout; @@ -3380,9 +3382,11 @@ static void __neigh_notify(struct neighbour *n, int type, int flags, goto errout; } rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC); - return; + goto out; errout: rtnl_set_sk_err(net, RTNLGRP_NEIGH, err); +out: + rcu_read_unlock(); } void neigh_app_ns(struct neighbour *n) -- 2.39.5