From 4c62337d8f1727f5005e41a141fe42c0154c21f9 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 13 Nov 2019 21:28:31 +0300 Subject: [PATCH] net: cdc_ncm: Signedness bug in cdc_ncm_set_dgram_size() commit a56dcc6b455830776899ce3686735f1172e12243 upstream. This code is supposed to test for negative error codes and partial reads, but because sizeof() is size_t (unsigned) type then negative error codes are type promoted to high positive values and the condition doesn't work as expected. Fixes: 332f989a3b00 ("CDC-NCM: handle incomplete transfer of MTU") Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller Signed-off-by: Nobuhiro Iwamatsu Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/cdc_ncm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index a57d82e..1f57a6a 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -579,7 +579,7 @@ static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size) err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE, USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE, 0, iface_no, &max_datagram_size, sizeof(max_datagram_size)); - if (err < sizeof(max_datagram_size)) { + if (err != sizeof(max_datagram_size)) { dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n"); goto out; } -- 2.7.4