diff options
| author | Song Yoong Siang <yoong.siang.song@intel.com> | 2021-08-25 08:55:29 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-08-25 10:59:39 +0100 |
| commit | a6451192da2691dcf39507bd758dde35d4606ee1 (patch) | |
| tree | 7e58bd24f791347951de1e37bf486ad9150e5536 | |
| parent | 85520079afce885b80647fbd0d13d8f03d057167 (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.c | 12 |
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; |