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 DBB5338FB0; Tue, 29 Apr 2025 17:28:14 +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=1745947694; cv=none; b=A1UJ6Lg9wd0c2cYktqzA8uTDom1fJv3ARZXa5yiPw0kCB63ktRrSd5tqvGm5NrtBgq9dPQSGIGpUty4DIcaH9r6cUOPde6pEqlM+c4q0wa91a0yGWY95ZxKfLTpbM4tzvadNIfj7wug9AMMTXLP09yKh1Df4G6eg/ds9dHOqu9U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745947694; c=relaxed/simple; bh=xeOOMGcQ9+BrmMAS+47vErxsL1uDjqy5DuVtgCSdYjE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RW6KsBt0b0iXvrR3yU4mx/dRqF0q7ScPZGChhvn+82VH3eOo1sJirHWHB7NRWLO6rhbU0ldEH1AWcTzQYj/avs1eh8xCylMHsblkV8soqMLKv3m3Um+M1RKQaWzbdIbY6WsbpoK7JMFL5oiUOehjZGluq7eeEH9InwZP7XFW6g4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TYAAtDCI; 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="TYAAtDCI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 430CEC4CEE9; Tue, 29 Apr 2025 17:28:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745947694; bh=xeOOMGcQ9+BrmMAS+47vErxsL1uDjqy5DuVtgCSdYjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TYAAtDCI9xN96w50ec87uwnGh9Yazpvg1p3bPeWFRsKJZYRLQtWlxc2gGc/Duf/nN 8QOA+0/8om8bIZWzils+0jMc6pZYePTbf9nhnKnZxABqa71lzryOrrtjGL3OBmVELj 5JHi2vnSFIqu9XODvxDGy29EJAQRp3tV0dysyCz0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexei Starovoitov , Eduard Zingerman , Justin Iurman , Simon Horman , Paolo Abeni , Sasha Levin Subject: [PATCH 6.12 070/280] net: lwtunnel: disable BHs when required Date: Tue, 29 Apr 2025 18:40:11 +0200 Message-ID: <20250429161117.972499882@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161115.008747050@linuxfoundation.org> References: <20250429161115.008747050@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Justin Iurman [ Upstream commit c03a49f3093a4903c8a93c8b5c9a297b5343b169 ] In lwtunnel_{output|xmit}(), dev_xmit_recursion() may be called in preemptible scope for PREEMPT kernels. This patch disables BHs before calling dev_xmit_recursion(). BHs are re-enabled only at the end, since we must ensure the same CPU is used for both dev_xmit_recursion_inc() and dev_xmit_recursion_dec() (and any other recursion levels in some cases) in order to maintain valid per-cpu counters. Reported-by: Alexei Starovoitov Closes: https://lore.kernel.org/netdev/CAADnVQJFWn3dBFJtY+ci6oN1pDFL=TzCmNbRgey7MdYxt_AP2g@mail.gmail.com/ Reported-by: Eduard Zingerman Closes: https://lore.kernel.org/netdev/m2h62qwf34.fsf@gmail.com/ Fixes: 986ffb3a57c5 ("net: lwtunnel: fix recursion loops") Signed-off-by: Justin Iurman Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250416160716.8823-1-justin.iurman@uliege.be Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/core/lwtunnel.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index 4417a18b3e951..f63586c9ce021 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -332,6 +332,8 @@ int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) struct dst_entry *dst; int ret; + local_bh_disable(); + if (dev_xmit_recursion()) { net_crit_ratelimited("%s(): recursion limit reached on datapath\n", __func__); @@ -347,8 +349,10 @@ int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) lwtstate = dst->lwtstate; if (lwtstate->type == LWTUNNEL_ENCAP_NONE || - lwtstate->type > LWTUNNEL_ENCAP_MAX) - return 0; + lwtstate->type > LWTUNNEL_ENCAP_MAX) { + ret = 0; + goto out; + } ret = -EOPNOTSUPP; rcu_read_lock(); @@ -363,11 +367,13 @@ int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) if (ret == -EOPNOTSUPP) goto drop; - return ret; + goto out; drop: kfree_skb(skb); +out: + local_bh_enable(); return ret; } EXPORT_SYMBOL_GPL(lwtunnel_output); @@ -379,6 +385,8 @@ int lwtunnel_xmit(struct sk_buff *skb) struct dst_entry *dst; int ret; + local_bh_disable(); + if (dev_xmit_recursion()) { net_crit_ratelimited("%s(): recursion limit reached on datapath\n", __func__); @@ -395,8 +403,10 @@ int lwtunnel_xmit(struct sk_buff *skb) lwtstate = dst->lwtstate; if (lwtstate->type == LWTUNNEL_ENCAP_NONE || - lwtstate->type > LWTUNNEL_ENCAP_MAX) - return 0; + lwtstate->type > LWTUNNEL_ENCAP_MAX) { + ret = 0; + goto out; + } ret = -EOPNOTSUPP; rcu_read_lock(); @@ -411,11 +421,13 @@ int lwtunnel_xmit(struct sk_buff *skb) if (ret == -EOPNOTSUPP) goto drop; - return ret; + goto out; drop: kfree_skb(skb); +out: + local_bh_enable(); return ret; } EXPORT_SYMBOL_GPL(lwtunnel_xmit); @@ -427,6 +439,8 @@ int lwtunnel_input(struct sk_buff *skb) struct dst_entry *dst; int ret; + DEBUG_NET_WARN_ON_ONCE(!in_softirq()); + if (dev_xmit_recursion()) { net_crit_ratelimited("%s(): recursion limit reached on datapath\n", __func__); -- 2.39.5