4.4-stable review patch. If anyone has any objections, please let me know.
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From: Yu Zhao yuzhao@google.com
[ Upstream commit f7b2a56e1f3dcbdb4cf09b2b63e859ffe0e09df8 ]
Cancel pending work before freeing smsc75xx private data structure during binding. This fixes the following crash in the driver:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000050 IP: mutex_lock+0x2b/0x3f <snipped> Workqueue: events smsc75xx_deferred_multicast_write [smsc75xx] task: ffff8caa83e85700 task.stack: ffff948b80518000 RIP: 0010:mutex_lock+0x2b/0x3f <snipped> Call Trace: smsc75xx_deferred_multicast_write+0x40/0x1af [smsc75xx] process_one_work+0x18d/0x2fc worker_thread+0x1a2/0x269 ? pr_cont_work+0x58/0x58 kthread+0xfa/0x10a ? pr_cont_work+0x58/0x58 ? rcu_read_unlock_sched_notrace+0x48/0x48 ret_from_fork+0x22/0x40
Signed-off-by: Yu Zhao yuzhao@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/usb/smsc75xx.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/net/usb/smsc75xx.c +++ b/drivers/net/usb/smsc75xx.c @@ -1506,6 +1506,7 @@ static void smsc75xx_unbind(struct usbne { struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]); if (pdata) { + cancel_work_sync(&pdata->set_multicast); netif_dbg(dev, ifdown, dev->net, "free pdata\n"); kfree(pdata); pdata = NULL;