This is a note to let you know that I've just added the patch titled
usb: gadget: ether: Fix race between gether_disconnect and rx_submit
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From d29fcf7078bc8be2b6366cbd4418265b53c94fac Mon Sep 17 00:00:00 2001
From: Kiruthika Varadarajan <Kiruthika.Varadarajan@xxxxxxxxxx>
Date: Tue, 18 Jun 2019 08:39:06 +0000
Subject: usb: gadget: ether: Fix race between gether_disconnect and rx_submit
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: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Kiruthika Varadarajan <Kiruthika.Varadarajan@xxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
---
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 737bd77a575d..2929bb47a618 100644
--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -186,11 +186,12 @@ 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;
@@ -214,6 +215,7 @@ 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 = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
if (skb == NULL) {
--
2.22.0
