From 1afac196c16753f93d482eedb9aeb802e740e67e Mon Sep 17 00:00:00 2001 From: Cathy Luo Date: Tue, 20 Sep 2016 20:49:02 +0530 Subject: [PATCH] mwifiex: fix kernel crash for USB chipsets Following crash issue is observed during TCP traffic stress test [ 2253.625439] NMI watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [kworker/u17:1:5191] [ 2253.625520] Call Trace: [ 2253.625527] [] ? moal_spin_lock+0x30/0x30 [usb8xxx] [ 2253.625533] [] ? wlan_wmm_lists_empty+0xb/0xf0 [mlan] [ 2253.625537] [] mlan_main_process+0x1b3/0x720 [mlan] [ 2253.625540] [] woal_main_work_queue+0x45/0x80 [usb8xxx] [ 2253.625543] [] process_one_work+0x150/0x3f0 [ 2253.625545] [] worker_thread+0x121/0x520 [ 2253.625547] [] ? rescuer_thread+0x330/0x330 [ 2253.625549] [] kthread+0xd2/0xf0 [ 2253.625551] [] ? kthread_create_on_node+0x1c0/0x1c0 [ 2253.625553] [] ret_from_fork+0x7c/0xb0 [ 2253.625555] [] ? kthread_create_on_node+0x1c0/0x1c0 In mwifiex_usb_tx_complete(), we are updating port->block_status first and then freeing the skb attached to that URB. We may end up attaching new skb to URB in a corner case and same will be freed. This results in the kernel crash. The problem is solved by changing the sequence. Signed-off-by: Cathy Luo Signed-off-by: Shengzhen Li Signed-off-by: Amitkumar Karwar Signed-off-by: Kalle Valo --- drivers/net/wireless/marvell/mwifiex/usb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c index 8a20620fa119..e8283dc1f088 100644 --- a/drivers/net/wireless/marvell/mwifiex/usb.c +++ b/drivers/net/wireless/marvell/mwifiex/usb.c @@ -273,6 +273,8 @@ static void mwifiex_usb_tx_complete(struct urb *urb) } else { mwifiex_dbg(adapter, DATA, "%s: DATA\n", __func__); + mwifiex_write_data_complete(adapter, context->skb, 0, + urb->status ? -1 : 0); for (i = 0; i < MWIFIEX_TX_DATA_PORT; i++) { port = &card->port[i]; if (context->ep == port->tx_data_ep) { @@ -282,8 +284,6 @@ static void mwifiex_usb_tx_complete(struct urb *urb) } } adapter->data_sent = false; - mwifiex_write_data_complete(adapter, context->skb, 0, - urb->status ? -1 : 0); } if (card->mc_resync_flag) -- 2.39.5