From c9ffc78745f89e300fe704348dd8e6800acf4d18 Mon Sep 17 00:00:00 2001 From: Harish Jenny K N Date: Fri, 9 Sep 2016 11:30:42 +0200 Subject: [PATCH] usb: gadget: NCM: Protect dev->port_usb using dev->lock This commit incorporates findings from https://lkml.org/lkml/2016/4/25/594 The function has been modified to make sure we hold the dev lock when accessing the net device pointer. Acked-by: Jim Baxter Signed-off-by: Harish Jenny K N Signed-off-by: Felipe Balbi --- drivers/usb/gadget/function/u_ether.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index 9c8c9ed1dc9e..8cb08033b7c1 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -553,14 +553,16 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, spin_lock_irqsave(&dev->lock, flags); if (dev->port_usb) skb = dev->wrap(dev->port_usb, skb); - spin_unlock_irqrestore(&dev->lock, flags); if (!skb) { /* Multi frame CDC protocols may store the frame for * later which is not a dropped frame. */ if (dev->port_usb && - dev->port_usb->supports_multi_frame) + dev->port_usb->supports_multi_frame) { + spin_unlock_irqrestore(&dev->lock, flags); goto multiframe; + } + spin_unlock_irqrestore(&dev->lock, flags); goto drop; } } @@ -578,6 +580,7 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, req->zero = 0; else req->zero = 1; + spin_unlock_irqrestore(&dev->lock, flags); /* use zlp framing on tx for strict CDC-Ether conformance, * though any robust network rx path ignores extra padding. -- 2.39.5