[PATCH 5.9 033/252] net: stmmac: Use rtnl_lock/unlock on netif_set_real_num_rx_queues() call

Greg Kroah-Hartman
2020-11-23T12:43:31Z

From: Wong Vee Khee <vee.khee.wong@intel.com>

[ Upstream commit 8e5debed39017836a850c6c7bfacc93299d19bad ]

Fix an issue where dump stack is printed on suspend resume flow due to
netif_set_real_num_rx_queues() is not called with rtnl_lock held().

Fixes: 686cff3d7022 ("net: stmmac: Fix incorrect location to set real_num_rx|tx_queues")
Reported-by: Christophe ROULLIER <christophe.roullier@st.com>
Tested-by: Christophe ROULLIER <christophe.roullier@st.com>
Cc: Alexandre TORGUE <alexandre.torgue@st.com>
Reviewed-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Wong Vee Khee <vee.khee.wong@intel.com>
Link: https://lore.kernel.org/r/20201115074210.23605-1-vee.khee.wong@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -5170,6 +5170,7 @@ int stmmac_resume(struct device *dev)
return ret;
}

+ rtnl_lock();
mutex_lock(&priv->lock);

stmmac_reset_queues_param(priv);
@@ -5185,6 +5186,7 @@ int stmmac_resume(struct device *dev)
stmmac_enable_all_queues(priv);

mutex_unlock(&priv->lock);
+ rtnl_unlock();

if (!device_may_wakeup(priv->device) || !priv->plat->pmt) {
rtnl_lock();