From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 31db0dbd72444abe645d90c20ecb84d668f5af5e ]
In current kernels, small allocations never actually fail so this patch shouldn't affect runtime.
Originally this error handling code written with the idea that if the "serial->tiocmget" allocation failed, then we would continue operating instead of bailing out early. But in later years we added an unchecked dereference on the next line.
serial->tiocmget->serial_state_notification = kzalloc(); ^^^^^^^^^^^^^^^^^^
Since these allocations are never going fail in real life, this is mostly a philosophical debate, but I think bailing out early is the correct behavior that the user would want. And generally it's safer to bail as soon an error happens.
Fixes: af0de1303c4e ("usb: hso: obey DMA rules in tiocmget") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Reviewed-by: Johan Hovold johan@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/hso.c | 37 ++++++++++++++++++------------------- 1 file changed, 18 insertions(+), 19 deletions(-)
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index ba366e9347f7..b947b7a9ffb8 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -2618,29 +2618,28 @@ static struct hso_device *hso_create_bulk_serial_device( num_urbs = 2; serial->tiocmget = kzalloc(sizeof(struct hso_tiocmget), GFP_KERNEL); + if (!serial->tiocmget) + goto exit; serial->tiocmget->serial_state_notification = kzalloc(sizeof(struct hso_serial_state_notification), GFP_KERNEL); - /* it isn't going to break our heart if serial->tiocmget - * allocation fails don't bother checking this. - */ - if (serial->tiocmget && serial->tiocmget->serial_state_notification) { - tiocmget = serial->tiocmget; - tiocmget->endp = hso_get_ep(interface, - USB_ENDPOINT_XFER_INT, - USB_DIR_IN); - if (!tiocmget->endp) { - dev_err(&interface->dev, "Failed to find INT IN ep\n"); - goto exit; - } - - tiocmget->urb = usb_alloc_urb(0, GFP_KERNEL); - if (tiocmget->urb) { - mutex_init(&tiocmget->mutex); - init_waitqueue_head(&tiocmget->waitq); - } else - hso_free_tiomget(serial); + if (!serial->tiocmget->serial_state_notification) + goto exit; + tiocmget = serial->tiocmget; + tiocmget->endp = hso_get_ep(interface, + USB_ENDPOINT_XFER_INT, + USB_DIR_IN); + if (!tiocmget->endp) { + dev_err(&interface->dev, "Failed to find INT IN ep\n"); + goto exit; } + + tiocmget->urb = usb_alloc_urb(0, GFP_KERNEL); + if (tiocmget->urb) { + mutex_init(&tiocmget->mutex); + init_waitqueue_head(&tiocmget->waitq); + } else + hso_free_tiomget(serial); } else num_urbs = 1;