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 A729B1AE09D; Tue, 18 Jun 2024 12:42:12 +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=1718714532; cv=none; b=brMXepVlNaEFCx2raYhAjps6KHipokS83h43kGsg68qYaYG/T/iUPAoQn2g4kA512VJzQfATVu5xhOwNUEtSB6rkbhYJBqIaqVrjbhOxBbOnCmjrN4HRFn5iZeTp1gio3SB53K5mf/2x32wVq/Tr7rZkzqflKfxSZArW4Dx+CB0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718714532; c=relaxed/simple; bh=/nnsUQdE5YTf+S/puaXWvhWSGWHuL07yhsepzBghLlc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rvJLppFzFt445w465osG0wzz/qLDSjS5J6uz/uT/yKM7A0QEOhcQp0y81HTRzwCRtGiH6otAuVd6NOTbNLE+qaauzOTzg5BHX2QG9lEbXlyeWszGLZeklmWrIXei/iIwGKahVv5rcIpfUP+aW4vnMHTg0Q6T3ESDtN/uUY7FSxU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pqIniyZQ; 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="pqIniyZQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E77CC3277B; Tue, 18 Jun 2024 12:42:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718714532; bh=/nnsUQdE5YTf+S/puaXWvhWSGWHuL07yhsepzBghLlc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pqIniyZQ7kxT/vLCu5F0oA63JmUdJQFmUHr1oHsjNVgK+GI55Rc4PNGXrPcvEC8UN iZLfblksgIL6wom1ePK0oxHyPi6X2Le5HpvgC7XHEruKTrgXweHFKlMc7URJvjoR4Y aJdBMaMVCCagWmTiA/IkPQTS94joebxc/i9ecjiM1GIU2EjPkSg+rff8OI3gXWtnL/ cD/CdXeIQrzHqFsXsY9cIu3t/ZcdWc3gbeY4Mo6YjhIDZuH2Ejf51gUobzjWMEywkk g7oEVZ3yPUsJzgKWRstphxKgpoBO7iXes3ur8OZ9WiFKdAhYBapPsnmpmfD/6GwgcF qe6ljvtEdAGJg== 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 5.15 16/21] net: ipv6: rpl_iptunnel: block BH in rpl_output() and rpl_input() Date: Tue, 18 Jun 2024 08:41:15 -0400 Message-ID: <20240618124139.3303801-16-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240618124139.3303801-1-sashal@kernel.org> References: <20240618124139.3303801-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.161 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