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 22B0925DAFD; Tue, 11 Mar 2025 15:13:19 +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=1741705999; cv=none; b=UUFMWgaCI5UccYIBEB6hQyRAJQsFnPcL1Q7K5pTW5m8FRh9400p7FkfanA0SUoGAPGNeoklNsOS5T8k/tZvemkkvgx+AGAJ/SNgx7o/IcvgZG6ktHSB1vaPwxKKWmjnud5iLmez4qU73Ry+rGiw9PZNxodRMTzWtTMO8pGwq7hM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741705999; c=relaxed/simple; bh=RB5J4l+O0y24ZibzdnkVsUmjF1ktD5NUAELtT6EPvyY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UQHB8bcR2hsRFpaTuMK4vZIDP/55qvrl/1ld+wYzHXibS4X371WObvcZvg9s47Ca029LbGTJ4N2p4ALDySvZ8VezsZe0HZ/xXM3hmFUGRcE2cqTc9gjIWjXpMO8Rj5HMftr4ObRXBl4Rq7wCtmxam6E8JEEubXBhjAz4vp2cSIk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=B35lcx63; 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="B35lcx63" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A067EC4CEE9; Tue, 11 Mar 2025 15:13:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741705999; bh=RB5J4l+O0y24ZibzdnkVsUmjF1ktD5NUAELtT6EPvyY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B35lcx63Djwwm9+EwESk2pNs3fdDtOHo08SM4TrCQ2kBXRCTKzpbpOYtlJFHi67Hf GKNlyZ2raeZHmDa/PXSIRIDXj8n/ZtH/0t6tkNhceoKBsoVeutdOgxzGEE2Wzceukm kOsAYWO4KDd29bd7lsVFpBp3CJIzfrjCVZ9Tq8ic= 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 5.4 209/328] arp: use RCU protection in arp_xmit() Date: Tue, 11 Mar 2025 15:59:39 +0100 Message-ID: <20250311145723.210793579@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 a42b69f692165ec39db42d595f4f65a4c8f42e44 ] arp_xmit() can be called without RTNL or RCU protection. Use RCU protection to avoid potential UAF. Fixes: 29a26a568038 ("netfilter: Pass struct net into the netfilter hooks") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250207135841.1948589-5-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/arp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index b8fe943ae89d0..9455b96449e5a 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -637,10 +637,12 @@ static int arp_xmit_finish(struct net *net, struct sock *sk, struct sk_buff *skb */ void arp_xmit(struct sk_buff *skb) { + rcu_read_lock(); /* Send it off, maybe filter it using firewalling first. */ NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, - dev_net(skb->dev), NULL, skb, NULL, skb->dev, + dev_net_rcu(skb->dev), NULL, skb, NULL, skb->dev, arp_xmit_finish); + rcu_read_unlock(); } EXPORT_SYMBOL(arp_xmit); -- 2.39.5