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 DDE0E1586C4; Tue, 23 Jul 2024 18:32:19 +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=1721759540; cv=none; b=rRVukd338X4YhhemS/YfdRqLko1MgYGOrSCMiwzx19YUfg6vtfmj31xt60l0DxGXLmSFFxkOaCjPT6eNx8kOjpYqxEN/qRIZTFG62ayVcarrYJwiAXYeCSAaLlUTdyNyK/PQPHT1fj8cSLOQxELgGdEzPLRHzdmyUYptUVjvGtg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721759540; c=relaxed/simple; bh=+pv4NaMJzO+MQzjMjPX6eBDhxVIEpp9oL2FkH4udfzs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KG5RvOh4YeNnaqDl8hli4UxkWPRsipeC7sJWf4I6YjQhq+ZGLZ8nNrMKMyauqhFp9VVOAMKqjO8/RL9DVacthKkHZthpqY0GcxO/oao0lWPHfEyyBGw/tPfR97RE1QVLIYxdTikQdWzjFyL8sKaqbukGiD+6tb+FuOP1Am/aVyM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1wTA6pvc; 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="1wTA6pvc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E95EFC4AF0A; Tue, 23 Jul 2024 18:32:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721759539; bh=+pv4NaMJzO+MQzjMjPX6eBDhxVIEpp9oL2FkH4udfzs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1wTA6pvcIBmyTqfUuCN7CfJENuhk+crhRQZwExq1J2OujMgHUO8ODX2O6UbPGu65A B8kRyj8KRI0yuZ6khF9HOSZnVGkD8qiPBFic0FyTxYgWtpL8WwSmOLx6xDr62BB6I3 0nEhm431GICBHmpAQcIuX6axSjCYXc6I0f8u0psY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Alexander Aring , Paolo Abeni , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 027/129] net: ipv6: rpl_iptunnel: block BH in rpl_output() and rpl_input() Date: Tue, 23 Jul 2024 20:22:55 +0200 Message-ID: <20240723180405.840133128@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240723180404.759900207@linuxfoundation.org> References: <20240723180404.759900207@linuxfoundation.org> User-Agent: quilt/0.67 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ 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 a013b92cbb860..2c83b7586422d 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); @@ -268,23 +268,21 @@ static int rpl_input(struct sk_buff *skb) return err; } - preempt_disable(); + local_bh_disable(); dst = dst_cache_get(&rlwt->cache); - preempt_enable(); if (!dst) { 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_drop(skb); skb_dst_set(skb, dst); } + local_bh_enable(); err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) -- 2.43.0