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 2C10525484E; Tue, 29 Apr 2025 18:11:48 +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=1745950309; cv=none; b=RmK8SKn91BxpDGqrusFs/zSf+bZV0c5IMHlwlMFvv3xdGy8z59ebc1WKRzB+bhZ4s+WFM7k0UVRJZCEUOpA8xpNBnnSgw3D40bvtem2zBfJ2YemBbXb6xkWOoAJaCmtmu3DYEAde93hSFE0GamSbawatMHP1dC2ExJx/3To/c3c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745950309; c=relaxed/simple; bh=xInd3rLPaUHth0LV5gCtkgjFWQaoLKlXefZqS2wVA0w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sUMJzhDpWgCwq6t4bRrNzWGE1joZs1bm446RP0bgV8LZi3V0U6zW89KL0u0cWQBoPNPrjS9PydOkM6cQzJBHjDe+m6fXN3dqNTSAki9FMcEUsyfnjAEO06hFKaNL8wbT4lNwwkWI9721cDyGWuk1eU1pGzHM6qzcNkhyA7HJ5J0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CI6z1/Z3; 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="CI6z1/Z3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B41FC4CEE3; Tue, 29 Apr 2025 18:11:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745950308; bh=xInd3rLPaUHth0LV5gCtkgjFWQaoLKlXefZqS2wVA0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CI6z1/Z3WFyOZC97+HmVtiO9R0FU/cHhQuM4M1i6a08v7E404sg+7gyOSZTOvRcFG EK2V3edrtuqafa1ZE6FRZb83pfi7JRdfmgfWLdugydZlzgBxtp3Z3mn/IP56Q6ADAZ hOzNNACLib/t70vD/MnDnPZLE0vd+aUbmcz/9KGc= 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 6.6 054/204] net: lwtunnel: disable BHs when required Date: Tue, 29 Apr 2025 18:42:22 +0200 Message-ID: <20250429161101.616994902@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161059.396852607@linuxfoundation.org> References: <20250429161059.396852607@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev 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: 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