linux-kernel - [PATCH] virtio-net: disable delayed refill when setting up xdp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250402054210.67623-1-minhquangbui99@gmail.com>
Date: Wed,  2 Apr 2025 12:42:10 +0700
From: Bui Quang Minh <minhquangbui99@...il.com>
To: virtualization@...ts.linux.dev
Cc: "Michael S . Tsirkin" <mst@...hat.com>,
	Jason Wang <jasowang@...hat.com>,
	Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Alexei Starovoitov <ast@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	Jesper Dangaard Brouer <hawk@...nel.org>,
	John Fastabend <john.fastabend@...il.com>,
	Eugenio Pérez <eperezma@...hat.com>,
	"David S . Miller" <davem@...emloft.net>,
	netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	bpf@...r.kernel.org,
	Bui Quang Minh <minhquangbui99@...il.com>
Subject: [PATCH] virtio-net: disable delayed refill when setting up xdp

When setting up XDP for a running interface, we call napi_disable() on
the receive queue's napi. In delayed refill_work, it also calls
napi_disable() on the receive queue's napi. This can leads to deadlock
when napi_disable() is called on an already disabled napi. This commit
fixes this by disabling future and cancelling all inflight delayed
refill works before calling napi_disabled() in virtnet_xdp_set.

Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set")
Signed-off-by: Bui Quang Minh <minhquangbui99@...il.com>
---
 drivers/net/virtio_net.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7e4617216a4b..33406d59efe2 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -5956,6 +5956,15 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 	if (!prog && !old_prog)
 		return 0;
 
+	/*
+	 * Make sure refill_work does not run concurrently to
+	 * avoid napi_disable race which leads to deadlock.
+	 */
+	if (netif_running(dev)) {
+		disable_delayed_refill(vi);
+		cancel_delayed_work_sync(&vi->refill);
+	}
+
 	if (prog)
 		bpf_prog_add(prog, vi->max_queue_pairs - 1);
 
@@ -6004,6 +6013,8 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 			virtnet_napi_tx_enable(&vi->sq[i]);
 		}
 	}
+	if (netif_running(dev))
+		enable_delayed_refill(vi);
 
 	return 0;
 
@@ -6019,6 +6030,7 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 			virtnet_napi_enable(&vi->rq[i]);
 			virtnet_napi_tx_enable(&vi->sq[i]);
 		}
+		enable_delayed_refill(vi);
 	}
 	if (prog)
 		bpf_prog_sub(prog, vi->max_queue_pairs - 1);
-- 
2.43.0