mwifiex: fix division by zero in fw download path

stable inclusion
from stable-5.10.80
commit fd1e4d8c61ef577c1b21f96d6a04ab0cb771f9d6
bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fd1e4d8c61ef577c1b21f96d6a04ab0cb771f9d6

--------------------------------

commit 89f8765a upstream.

Add the missing endpoint sanity checks to probe() to avoid division by
zero in mwifiex_write_data_sync() in case a malicious device has broken
descriptors (or when doing descriptor fuzz testing).

Only add checks for the firmware-download boot stage, which require both
command endpoints, for now. The driver looks like it will handle a
missing endpoint during normal operation without oopsing, albeit not
very gracefully as it will try to submit URBs to the default pipe and
fail.

Note that USB core will reject URBs submitted for endpoints with zero
wMaxPacketSize but that drivers doing packet-size calculations still
need to handle this (cf. commit 2548288b ("USB: Fix: Don't skip
endpoint descriptors with maxpacket=0")).

Fixes: 4daffe35 ("mwifiex: add support for Marvell USB8797 chipset")
Cc: stable@vger.kernel.org      # 3.5
Cc: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Reviewed-by: NBrian Norris <briannorris@chromium.org>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211027080819.6675-4-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/wireless/marvell/mwifiex/usb.c

@@ -506,6 +506,22 @@ static int mwifiex_usb_probe(struct usb_interface *intf,
 		}
 	}
 
+	switch (card->usb_boot_state) {
+	case USB8XXX_FW_DNLD:
+		/* Reject broken descriptors. */
+		if (!card->rx_cmd_ep || !card->tx_cmd_ep)
+			return -ENODEV;
+		if (card->bulk_out_maxpktsize == 0)
+			return -ENODEV;
+		break;
+	case USB8XXX_FW_READY:
+		/* Assume the driver can handle missing endpoints for now. */
+		break;
+	default:
+		WARN_ON(1);
+		return -ENODEV;
+	}
+
 	usb_set_intfdata(intf, card);
 
 	ret = mwifiex_add_card(card, &card->fw_done, &usb_ops,