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 DE8891A5A4 for ; Mon, 9 Oct 2023 13:22:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nLw2g9cb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5999CC433C8; Mon, 9 Oct 2023 13:22:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696857725; bh=sGH/67FV1O1bHQfIyIlCve0vpbnjAls8V4P0zKasMJM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nLw2g9cb07TY5KOsRJI8I6pDAvXSu66nNfNzY1Zi+H8a9xF0ezveGfVmvXhaqeu0F 3WSFC5az8sUTdb1cvp2AWCu/4tRF9llQNlx9rqrOIrWT1RotLrQ7ENykt63dyg9lEC wnqV+jSXwl5+EhTUxAum7muPNocQ6GMi8WZxfw2s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Ahern , "David S. Miller" , Sasha Levin Subject: [PATCH 6.1 110/162] neighbour: fix data-races around n->output Date: Mon, 9 Oct 2023 15:01:31 +0200 Message-ID: <20231009130125.963150186@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231009130122.946357448@linuxfoundation.org> References: <20231009130122.946357448@linuxfoundation.org> User-Agent: quilt/0.67 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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 5baa0433a15eadd729625004c37463acb982eca7 ] n->output field can be read locklessly, while a writer might change the pointer concurrently. Add missing annotations to prevent load-store tearing. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/neighbour.h | 2 +- net/bridge/br_netfilter_hooks.c | 2 +- net/core/neighbour.c | 10 +++++----- 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/include/net/neighbour.h b/include/net/neighbour.h index f6a8ecc6b1fa7..ccc4a0f8b4ad8 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -541,7 +541,7 @@ static inline int neigh_output(struct neighbour *n, struct sk_buff *skb, READ_ONCE(hh->hh_len)) return neigh_hh_output(hh, skb); - return n->output(n, skb); + return READ_ONCE(n->output)(n, skb); } static inline struct neighbour * diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 442198cb83909..01d690d9fe5f8 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -294,7 +294,7 @@ int br_nf_pre_routing_finish_bridge(struct net *net, struct sock *sk, struct sk_ /* tell br_dev_xmit to continue with forwarding */ nf_bridge->bridged_dnat = 1; /* FIXME Need to refragment */ - ret = neigh->output(neigh, skb); + ret = READ_ONCE(neigh->output)(neigh, skb); } neigh_release(neigh); return ret; diff --git a/net/core/neighbour.c b/net/core/neighbour.c index bafd72e5f5886..b20c9768d9f3f 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -410,7 +410,7 @@ static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev, */ __skb_queue_purge(&n->arp_queue); n->arp_queue_len_bytes = 0; - n->output = neigh_blackhole; + WRITE_ONCE(n->output, neigh_blackhole); if (n->nud_state & NUD_VALID) n->nud_state = NUD_NOARP; else @@ -920,7 +920,7 @@ static void neigh_suspect(struct neighbour *neigh) { neigh_dbg(2, "neigh %p is suspected\n", neigh); - neigh->output = neigh->ops->output; + WRITE_ONCE(neigh->output, neigh->ops->output); } /* Neighbour state is OK; @@ -932,7 +932,7 @@ static void neigh_connect(struct neighbour *neigh) { neigh_dbg(2, "neigh %p is connected\n", neigh); - neigh->output = neigh->ops->connected_output; + WRITE_ONCE(neigh->output, neigh->ops->connected_output); } static void neigh_periodic_work(struct work_struct *work) @@ -1449,7 +1449,7 @@ static int __neigh_update(struct neighbour *neigh, const u8 *lladdr, if (n2) n1 = n2; } - n1->output(n1, skb); + READ_ONCE(n1->output)(n1, skb); if (n2) neigh_release(n2); rcu_read_unlock(); @@ -3145,7 +3145,7 @@ int neigh_xmit(int index, struct net_device *dev, rcu_read_unlock(); goto out_kfree_skb; } - err = neigh->output(neigh, skb); + err = READ_ONCE(neigh->output)(neigh, skb); rcu_read_unlock(); } else if (index == NEIGH_LINK_TABLE) { -- 2.40.1