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 3D3DF253327; Tue, 29 Apr 2025 18:02:45 +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=1745949765; cv=none; b=VN2h//L5xbjO9ylgbxHko7qcKA0w6mAoMiE7/4a72DG2CPRai0/rNs79IDeoz39fpLOpvweCt+bAdrjJXWIx8ER5qCxZcXxWe+i99IsJhm5fwll8JjlkkhiorOhtmPHtdCtaZOccug8zxPzMqUteOAFnreZ75ySXs4QsyUEOyaI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745949765; c=relaxed/simple; bh=udF3PFrNks6aCs5N5gg7W71Q3cQwrrr/0boEIYgYyyk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f7qNyH5Stsh0qbUqsHH/m0AH6FR8LItO5LwTg5ClsFNRc5ubxrgtiV3UGfrHJ+tB3tzrVeAKKIYPkXi/38bgGZaqwDlIG8BM1Fe5bojLz11zKQY4BHCNqKnbbuJ3QOkVpOtTa71J5N1c6ab2UCA2zwRdcVuTLJgUtWK2TeFC5XM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Aj1OvD1z; 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="Aj1OvD1z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6AF2C4CEE3; Tue, 29 Apr 2025 18:02:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745949765; bh=udF3PFrNks6aCs5N5gg7W71Q3cQwrrr/0boEIYgYyyk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Aj1OvD1zeUP6pHdYtKXMsxggz+dhl3fOr7cCqIXSvRdOI+a/VN0bQ/kExxRPFfRe2 CWOp9RjUXDvEnsMLn7QdTIxY0KySEWi6ksnO2YWEupOs0lHN4J7sJJ0msKNXjN7fPq +2h7I/BBGU1whEZiQiWymNBvB/jwLhCc6rR194Cc= 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 6.1 049/167] net: lwtunnel: disable BHs when required Date: Tue, 29 Apr 2025 18:42:37 +0200 Message-ID: <20250429161053.745199705@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161051.743239894@linuxfoundation.org> References: <20250429161051.743239894@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 6.1-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