Merge tag 'usb-4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here are a number of small USB fixes for 4.2-rc2.  They revert one
  problem patch, fix some minor things, and add some new quirks for
  "broken" devices.

  All have been in linux-next successfully"

* tag 'usb-4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  cdc-acm: prevent infinite loop when parsing CDC headers.
  Revert "usb: host: ehci-msm: Use devm_ioremap_resource instead of devm_ioremap"
  usb: chipidea: otg: remove mutex unlock and lock while stop and start role
  uas: Set max_sectors_240 quirk for ASM1053 devices
  uas: Add US_FL_MAX_SECTORS_240 flag
  uas: Allow uas_use_uas_driver to return usb-storage flags

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 3e15add..5c8f581 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1142,11 +1142,16 @@ static int acm_probe(struct usb_interface *intf,
 	}
 
 	while (buflen > 0) {
+		elength = buffer[0];
+		if (!elength) {
+			dev_err(&intf->dev, "skipping garbage byte\n");
+			elength = 1;
+			goto next_desc;
+		}
 		if (buffer[1] != USB_DT_CS_INTERFACE) {
 			dev_err(&intf->dev, "skipping garbage\n");
 			goto next_desc;
 		}
-		elength = buffer[0];
 
 		switch (buffer[2]) {
 		case USB_CDC_UNION_TYPE: /* we've found it */