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authorSong Yoong Siang <yoong.siang.song@intel.com>2021-08-25 08:55:29 +0800
committerDavid S. Miller <davem@davemloft.net>2021-08-25 10:59:39 +0100
commita6451192da2691dcf39507bd758dde35d4606ee1 (patch)
tree7e58bd24f791347951de1e37bf486ad9150e5536
parent85520079afce885b80647fbd0d13d8f03d057167 (diff)
net: stmmac: fix kernel panic due to NULL pointer dereference of xsk_pool
After free xsk_pool, there is possibility that napi polling is still running in the middle, thus causes a kernel crash due to kernel NULL pointer dereference of rx_q->xsk_pool and tx_q->xsk_pool. Fix this by changing the XDP pool setup sequence to: 1. disable napi before free xsk_pool 2. enable napi after init xsk_pool The following kernel panic is observed without this patch: RIP: 0010:xsk_uses_need_wakeup+0x5/0x10 Call Trace: stmmac_napi_poll_rxtx+0x3a9/0xae0 [stmmac] __napi_poll+0x27/0x130 net_rx_action+0x233/0x280 __do_softirq+0xe2/0x2b6 run_ksoftirqd+0x1a/0x20 smpboot_thread_fn+0xac/0x140 ? sort_range+0x20/0x20 kthread+0x124/0x150 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 ---[ end trace a77c8956b79ac107 ]--- Fixes: bba2556efad6 ("net: stmmac: Enable RX via AF_XDP zero-copy") Cc: <stable@vger.kernel.org> # 5.13.x Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
index 105821b53020..2a616c6f7cd0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
@@ -34,18 +34,18 @@ static int stmmac_xdp_enable_pool(struct stmmac_priv *priv,
need_update = netif_running(priv->dev) && stmmac_xdp_is_enabled(priv);
if (need_update) {
- stmmac_disable_rx_queue(priv, queue);
- stmmac_disable_tx_queue(priv, queue);
napi_disable(&ch->rx_napi);
napi_disable(&ch->tx_napi);
+ stmmac_disable_rx_queue(priv, queue);
+ stmmac_disable_tx_queue(priv, queue);
}
set_bit(queue, priv->af_xdp_zc_qps);
if (need_update) {
- napi_enable(&ch->rxtx_napi);
stmmac_enable_rx_queue(priv, queue);
stmmac_enable_tx_queue(priv, queue);
+ napi_enable(&ch->rxtx_napi);
err = stmmac_xsk_wakeup(priv->dev, queue, XDP_WAKEUP_RX);
if (err)
@@ -72,10 +72,10 @@ static int stmmac_xdp_disable_pool(struct stmmac_priv *priv, u16 queue)
need_update = netif_running(priv->dev) && stmmac_xdp_is_enabled(priv);
if (need_update) {
+ napi_disable(&ch->rxtx_napi);
stmmac_disable_rx_queue(priv, queue);
stmmac_disable_tx_queue(priv, queue);
synchronize_rcu();
- napi_disable(&ch->rxtx_napi);
}
xsk_pool_dma_unmap(pool, STMMAC_RX_DMA_ATTR);
@@ -83,10 +83,10 @@ static int stmmac_xdp_disable_pool(struct stmmac_priv *priv, u16 queue)
clear_bit(queue, priv->af_xdp_zc_qps);
if (need_update) {
- napi_enable(&ch->rx_napi);
- napi_enable(&ch->tx_napi);
stmmac_enable_rx_queue(priv, queue);
stmmac_enable_tx_queue(priv, queue);
+ napi_enable(&ch->rx_napi);
+ napi_enable(&ch->tx_napi);
}
return 0;