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 0BF18374EA; Mon, 10 Mar 2025 18:18:43 +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=1741630723; cv=none; b=W79dORC1cB7RsE8iE8aH0a6PQEk7F3mSqx0skMLEPNoL5sLvfuGfedhaZ0VUSgNH/3wjM/8r5k/uvdAybmz0S1wXW3YShTtIgEemvFPMu9LNiFRln2J9VkFjv79hAF+PtbQLwayB6qt3q2K4J2W0C0J4GumAtUJUAV0IjrVjjEo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741630723; c=relaxed/simple; bh=qKZDy3R4q4b5KdIGbfznYc6HOFzZORk+K/Qm8NmwgZ4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Hys+4RkiNERIBbYkCEQwVPztoW0dbgr0bef/BiEWfX+BYpa/h3G+8v5UsEXKsWCNwSphbYkIisf1uJx0bKXid/N07n5KTTSk1uY2DpGW+v82dbFr0uuhl8qWiLvHMZ3bHxVOoainWejlxRmpQ0LpjKMKAxCvuy2IE4rb7RD0ZAg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Xk5OohmG; 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="Xk5OohmG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7ED26C4CEE5; Mon, 10 Mar 2025 18:18:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741630722; bh=qKZDy3R4q4b5KdIGbfznYc6HOFzZORk+K/Qm8NmwgZ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xk5OohmGzAkmWT5MHp9e+0rO5VK0M9TEWUPyB1YPPtA1sawUaHT5DUH++uUXVeoPx L14a44ZCHB2xthrKqbsYUz4WH7zhUy+wY48mxJa3s6864XRDQbwK7aNY5IiZvdPRKN R613uDreGFKGrNeqKS4IpeOco24qQnn+HY5jF4P4= 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 5.15 512/620] net: ipv6: fix dst ref loop on input in rpl lwt Date: Mon, 10 Mar 2025 18:05:58 +0100 Message-ID: <20250310170605.766496375@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170545.553361750@linuxfoundation.org> References: <20250310170545.553361750@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 5.15-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