From f1052d05ec5ae9cb1138d43b447c2937adae56d3 Mon Sep 17 00:00:00 2001 From: Kiruthika Varadarajan Date: Tue, 18 Jun 2019 08:39:06 +0000 Subject: [PATCH] usb: gadget: ether: Fix race between gether_disconnect and rx_submit commit d29fcf7078bc8be2b6366cbd4418265b53c94fac upstream. On spin lock release in rx_submit, gether_disconnect get a chance to run, it makes port_usb NULL, rx_submit access NULL port USB, hence null pointer crash. Fixed by releasing the lock in rx_submit after port_usb is used. Fixes: 2b3d942c4878 ("usb ethernet gadget: split out network core") Cc: Signed-off-by: Kiruthika Varadarajan Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/u_ether.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index 5d1bd13a56c1..d5fbc2352029 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -198,11 +198,12 @@ rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags) out = dev->port_usb->out_ep; else out = NULL; - spin_unlock_irqrestore(&dev->lock, flags); if (!out) + { + spin_unlock_irqrestore(&dev->lock, flags); return -ENOTCONN; - + } /* Padding up to RX_EXTRA handles minor disagreements with host. * Normally we use the USB "terminate on short read" convention; @@ -223,6 +224,7 @@ rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags) if (dev->port_usb->is_fixed) size = max_t(size_t, size, dev->port_usb->fixed_out_len); + spin_unlock_irqrestore(&dev->lock, flags); skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags); if (skb == NULL) { -- 2.20.1