qca_debug: Prevent crash on TX ring changes

[ Upstream commit f4e6064c97 ]

The qca_spi driver stop and restart the SPI kernel thread
(via ndo_stop & ndo_open) in case of TX ring changes. This is
a big issue because it allows userspace to prevent restart of
the SPI kernel thread (via signals). A subsequent change of
TX ring wrongly assume a valid spi_thread pointer which result
in a crash.

So prevent this by stopping the network traffic handling and
temporary park the SPI thread.

Fixes: 291ab06ecf ("net: qualcomm: new Ethernet over SPI driver for QCA7000")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20231206141222.52029-2-wahrenst@gmx.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Stefan Wahren 2023-12-06 15:12:20 +01:00 committed by Greg Kroah-Hartman
parent 27972f3276
commit 86aa2245df
2 changed files with 16 additions and 5 deletions

View File

@ -275,7 +275,6 @@ qcaspi_get_ringparam(struct net_device *dev, struct ethtool_ringparam *ring)
static int
qcaspi_set_ringparam(struct net_device *dev, struct ethtool_ringparam *ring)
{
const struct net_device_ops *ops = dev->netdev_ops;
struct qcaspi *qca = netdev_priv(dev);
if ((ring->rx_pending) ||
@ -283,14 +282,14 @@ qcaspi_set_ringparam(struct net_device *dev, struct ethtool_ringparam *ring)
(ring->rx_jumbo_pending))
return -EINVAL;
if (netif_running(dev))
ops->ndo_stop(dev);
if (qca->spi_thread)
kthread_park(qca->spi_thread);
qca->txr.count = max_t(u32, ring->tx_pending, TX_RING_MIN_LEN);
qca->txr.count = min_t(u16, qca->txr.count, TX_RING_MAX_LEN);
if (netif_running(dev))
ops->ndo_open(dev);
if (qca->spi_thread)
kthread_unpark(qca->spi_thread);
return 0;
}

View File

@ -552,6 +552,18 @@ qcaspi_spi_thread(void *data)
netdev_info(qca->net_dev, "SPI thread created\n");
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
if (kthread_should_park()) {
netif_tx_disable(qca->net_dev);
netif_carrier_off(qca->net_dev);
qcaspi_flush_tx_ring(qca);
kthread_parkme();
if (qca->sync == QCASPI_SYNC_READY) {
netif_carrier_on(qca->net_dev);
netif_wake_queue(qca->net_dev);
}
continue;
}
if ((qca->intr_req == qca->intr_svc) &&
!qca->txr.skb[qca->txr.head])
schedule();