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 959081A2FB1; Tue, 18 Jun 2024 12:41:09 +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=1718714469; cv=none; b=MoCZ1gbyawkzXiD/7YdYL7+nCivcFGX7TPt/P45quNuQpgd40IbQJDfIzAqr3tH4JC2vSiq1jX5MlxDdtRpckQG41wq2RjXSFkiIid3I3KHFqoZP8GbhOxSTegi2YvnEHrXDOWcFILjFTLVHLkbodp6PFotzpsw4mwuLx2gaG4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718714469; c=relaxed/simple; bh=/nnsUQdE5YTf+S/puaXWvhWSGWHuL07yhsepzBghLlc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aM5qtHjjRB8AkTvbq5LKiQVQumI5WK8l9pM6qpBkXicGcnllhQbsrJLPdaf6rRAp4yV5/QrJD8lUt0krhkMfxdQ/I9RLaqolhcjcjfN2jMkw0b0roF3VuSNIxPjtSuNjNyE03mjn566uGO6sLZtAJko+UMGZxowd8PSZ6gRrSxg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ml02p/n7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ml02p/n7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63752C3277B; Tue, 18 Jun 2024 12:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718714469; bh=/nnsUQdE5YTf+S/puaXWvhWSGWHuL07yhsepzBghLlc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ml02p/n7Rgh8nqo4KdoUE16Ix8Uk2R5sp/cZLCHg1/3IdpiyFz8lje3vmwnO9IfIh /TVKdvSdjJjvzxZxy9R6+uWeglH8EWbJmGGHkl0m01x50qmEhgTD5rQWwUof5BfMUq /BVEJnAVXYcez+wh+sLx0OzC3fhhWBJNLRxXeRtFp9Ba2JVA7Nmm8G7DwNP4UVF2tR SreRSzL3O3HinXJyOMqL6zpLizPU93IJbATSu7ZWIIzQVC6kFrceKeR6TbJa0vblXX OoQ28dGtIVX34FwyOCOvFZG7UbqHrbEzbP3LCIJ8XR+moU4aWeMYvIO7HyU9GNIhj0 IA78gC06p03KA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , Alexander Aring , Paolo Abeni , Jakub Kicinski , Sasha Levin , davem@davemloft.net, dsahern@kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 24/29] net: ipv6: rpl_iptunnel: block BH in rpl_output() and rpl_input() Date: Tue, 18 Jun 2024 08:39:50 -0400 Message-ID: <20240618124018.3303162-24-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240618124018.3303162-1-sashal@kernel.org> References: <20240618124018.3303162-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.94 Content-Transfer-Encoding: 8bit From: Eric Dumazet [ Upstream commit db0090c6eb12c31246438b7fe2a8f1b833e7a653 ] As explained in commit 1378817486d6 ("tipc: block BH before using dst_cache"), net/core/dst_cache.c helpers need to be called with BH disabled. Disabling preemption in rpl_output() is not good enough, because rpl_output() is called from process context, lwtunnel_output() only uses rcu_read_lock(). We might be interrupted by a softirq, re-enter rpl_output() and corrupt dst_cache data structures. Fix the race by using local_bh_disable() instead of preempt_disable(). Apply a similar change in rpl_input(). Signed-off-by: Eric Dumazet Cc: Alexander Aring Acked-by: Paolo Abeni Link: https://lore.kernel.org/r/20240531132636.2637995-3-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/rpl_iptunnel.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c index ff691d9f4a04f..26adbe7f8a2f0 100644 --- a/net/ipv6/rpl_iptunnel.c +++ b/net/ipv6/rpl_iptunnel.c @@ -212,9 +212,9 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb) if (unlikely(err)) goto drop; - preempt_disable(); + local_bh_disable(); dst = dst_cache_get(&rlwt->cache); - preempt_enable(); + local_bh_enable(); if (unlikely(!dst)) { struct ipv6hdr *hdr = ipv6_hdr(skb); @@ -234,9 +234,9 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb) goto drop; } - preempt_disable(); + local_bh_disable(); dst_cache_set_ip6(&rlwt->cache, dst, &fl6.saddr); - preempt_enable(); + local_bh_enable(); } skb_dst_drop(skb); @@ -268,9 +268,8 @@ static int rpl_input(struct sk_buff *skb) return err; } - preempt_disable(); + local_bh_disable(); dst = dst_cache_get(&rlwt->cache); - preempt_enable(); skb_dst_drop(skb); @@ -278,14 +277,13 @@ static int rpl_input(struct sk_buff *skb) ip6_route_input(skb); dst = skb_dst(skb); if (!dst->error) { - preempt_disable(); dst_cache_set_ip6(&rlwt->cache, dst, &ipv6_hdr(skb)->saddr); - preempt_enable(); } } else { skb_dst_set(skb, dst); } + local_bh_enable(); err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) -- 2.43.0