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 1C6C4749A for ; Thu, 12 Jan 2023 14:11:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74742C433EF; Thu, 12 Jan 2023 14:11:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673532670; bh=HxwE+veaRYixwckzaukWnmpKyE6DwSBJjs6f6LN2GMg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z6FUV2jelEu7VYtr5V1teljY5oUspfg77R4aqEEAwdInktluS5CkMMLMOtu9MZWOw 5clUSB8I8ulN8gdCe1KYBRaC+Fr6Q8eWJMnglA9jJmyp26+ayyOtYA4txup6aH6Vix sugX2PKTVvvvWLo/AgH7Ex/9BsTdgwCB+yxY3HJs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sebastian Andrzej Siewior , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.10 207/783] hsr: Add a rcu-read lock to hsr_forward_skb(). Date: Thu, 12 Jan 2023 14:48:43 +0100 Message-Id: <20230112135533.934680459@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Sebastian Andrzej Siewior [ Upstream commit 5aa2820177af650293b2f9f1873c1f6f8e4ad7a4 ] hsr_forward_skb() a skb and keeps information in an on-stack hsr_frame_info. hsr_get_node() assigns hsr_frame_info::node_src which is from a RCU list. This pointer is used later in hsr_forward_do(). I don't see a reason why this pointer can't vanish midway since there is no guarantee that hsr_forward_skb() is invoked from an RCU read section. Use rcu_read_lock() to protect hsr_frame_info::node_src from its assignment until it is no longer used. Fixes: f266a683a4804 ("net/hsr: Better frame dispatch") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/hsr/hsr_forward.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c index cb9b54a7abd2..90b0ed16552b 100644 --- a/net/hsr/hsr_forward.c +++ b/net/hsr/hsr_forward.c @@ -545,11 +545,13 @@ void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) { struct hsr_frame_info frame; + rcu_read_lock(); if (fill_frame_info(&frame, skb, port) < 0) goto out_drop; hsr_register_frame_in(frame.node_src, port, frame.sequence_nr); hsr_forward_do(&frame); + rcu_read_unlock(); /* Gets called for ingress frames as well as egress from master port. * So check and increment stats for master port only here. */ @@ -564,6 +566,7 @@ void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) return; out_drop: + rcu_read_unlock(); port->dev->stats.tx_dropped++; kfree_skb(skb); } -- 2.35.1