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 1B608250C0E; Wed, 5 Mar 2025 17:58:11 +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=1741197491; cv=none; b=lClLmu4uEObk/JaSt0SQcozc7nTdXNxof5TqwbkQYa/65chyAByKWf7AwOtO8PM0GbdRT6Y3D3t5KwwzhKod51pOFTx4/d+h7fVcVoI9T9XswaCRXiZFZ00PNDjzOlFgjubvCxQL157jVh9iXG9MWF8nfYYGBnnzzim5LM93DKY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741197491; c=relaxed/simple; bh=9plkugohKT+0zz0bFVE0K3fz3WojNrODcU2QuFTq8Fk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gCKLy7QN+xb//aJgr04/WP6CTjf7SoY38KH7ilLbhVyiBMRLBCDO+qirXzc11AeJsnJ8D6sNPb3fiiVX7qWWvX7+lH0jS0mLp9/dGx1nQ38lkQpNndsDKHYsO3w+AcNeDBGZ6I5MeOLaDQx+bIiLTZf8V336k7H38TYrBGyfuws= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JN9S8z/t; 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="JN9S8z/t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97B88C4CED1; Wed, 5 Mar 2025 17:58:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741197491; bh=9plkugohKT+0zz0bFVE0K3fz3WojNrODcU2QuFTq8Fk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JN9S8z/tY2x3hYMczRVz4zdhAKsJP520TDWJYGMgwoB4AMAUa7yAuO092frdsQ+VW EmPpF7Wm6L9T7zhxvm8rhSLb5jui91LfY2hYwvPh0gNgeSa+25fWlPuwFf4D+DnNbC Sh0ZIcFMVvaUoctC+APDnUHxBbB4B8Wutpt6nnmA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexander Aring , Ido Schimmel , Justin Iurman , Paolo Abeni , Sasha Levin Subject: [PATCH 6.1 142/176] net: ipv6: fix dst ref loop on input in rpl lwt Date: Wed, 5 Mar 2025 18:48:31 +0100 Message-ID: <20250305174511.146964479@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250305174505.437358097@linuxfoundation.org> References: <20250305174505.437358097@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Justin Iurman [ Upstream commit 13e55fbaec176119cff68a7e1693b251c8883c5f ] Prevent a dst ref loop on input in rpl_iptunnel. Fixes: a7a29f9c361f ("net: ipv6: add rpl sr tunnel") Cc: Alexander Aring Cc: Ido Schimmel Reviewed-by: Ido Schimmel Signed-off-by: Justin Iurman Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/ipv6/rpl_iptunnel.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c index 69b9bd90140dd..862ac1e2e191c 100644 --- a/net/ipv6/rpl_iptunnel.c +++ b/net/ipv6/rpl_iptunnel.c @@ -259,10 +259,18 @@ static int rpl_input(struct sk_buff *skb) { struct dst_entry *orig_dst = skb_dst(skb); struct dst_entry *dst = NULL; + struct lwtunnel_state *lwtst; struct rpl_lwt *rlwt; int err; - rlwt = rpl_lwt_lwtunnel(orig_dst->lwtstate); + /* We cannot dereference "orig_dst" once ip6_route_input() or + * skb_dst_drop() is called. However, in order to detect a dst loop, we + * need the address of its lwtstate. So, save the address of lwtstate + * now and use it later as a comparison. + */ + lwtst = orig_dst->lwtstate; + + rlwt = rpl_lwt_lwtunnel(lwtst); local_bh_disable(); dst = dst_cache_get(&rlwt->cache); @@ -277,7 +285,9 @@ static int rpl_input(struct sk_buff *skb) if (!dst) { ip6_route_input(skb); dst = skb_dst(skb); - if (!dst->error) { + + /* cache only if we don't create a dst reference loop */ + if (!dst->error && lwtst != dst->lwtstate) { local_bh_disable(); dst_cache_set_ip6(&rlwt->cache, dst, &ipv6_hdr(skb)->saddr); -- 2.39.5