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 5C73D1C6FFE; Wed, 5 Mar 2025 17:58:05 +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=1741197485; cv=none; b=A1FJDj46ejxcAyQlqQSh2DPeOzRk+rokKR9Z2m5pjzsjiEwrO4wpzj1gg1rnVvMBWCOqCIgh1DJCK2n5YuRqrYRb6Ip77dQqHGUMPlxmnXrJpheqiMDGbchTKOTwm+F5wdhVo7t4zS0kP3LDJo4T4R1ascTJGf0vvCnRyD6ppjA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741197485; c=relaxed/simple; bh=SwZNfs2lbkfu0beW0HK/SvyJ+bKdicEcuQxFYy+fwwM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HahExV/qnghJ6iuvyK1iR/73MCsVua/Tj7SjB6QcHP4ex7P8cG3mRaI0xZ0JfqT+YMRwfu6MosmEHst11dUd74YOi+BRGWMQEsoAwMhV5O1TtDq1lvbbFN4jb3FQoNF6hrIvSUGivBMUAF4d0nLdllGu2p3lO5R8lucu1Di58b4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VpTihVJ9; 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="VpTihVJ9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D81EAC4CED1; Wed, 5 Mar 2025 17:58:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741197485; bh=SwZNfs2lbkfu0beW0HK/SvyJ+bKdicEcuQxFYy+fwwM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VpTihVJ9SJdnT/z28ebP5ifjP08o8MYNckwtrnxjDLjID2knkLrwRBjjahSmsJIb0 U0W4CnbGTdWlwyBBhe/HB7Ho/ybR/rz/oE/CqkYN8mSg8ZgcvtkMp+Zm1ar0b4plOt /a1tGRE1yD4x8S6tJw+cHLprIbu7yw8KWrNu9qFo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Lebrun , Ido Schimmel , Justin Iurman , Paolo Abeni , Sasha Levin Subject: [PATCH 6.1 140/176] net: ipv6: fix dst ref loop on input in seg6 lwt Date: Wed, 5 Mar 2025 18:48:29 +0100 Message-ID: <20250305174511.067164408@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 c64a0727f9b1cbc63a5538c8c0014e9a175ad864 ] Prevent a dst ref loop on input in seg6_iptunnel. Fixes: af4a2209b134 ("ipv6: sr: use dst_cache in seg6_input") Cc: David Lebrun Cc: Ido Schimmel Reviewed-by: Ido Schimmel Signed-off-by: Justin Iurman Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/ipv6/seg6_iptunnel.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c index c161298c8b335..b186d85ec5b3f 100644 --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -472,10 +472,18 @@ static int seg6_input_core(struct net *net, struct sock *sk, { struct dst_entry *orig_dst = skb_dst(skb); struct dst_entry *dst = NULL; + struct lwtunnel_state *lwtst; struct seg6_lwt *slwt; int err; - slwt = seg6_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; + + slwt = seg6_lwt_lwtunnel(lwtst); local_bh_disable(); dst = dst_cache_get(&slwt->cache); @@ -490,7 +498,9 @@ static int seg6_input_core(struct net *net, struct sock *sk, 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(&slwt->cache, dst, &ipv6_hdr(skb)->saddr); -- 2.39.5