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authorErik Slagter <erik@slagter.name>2011-05-11 12:06:55 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-06-03 10:34:24 +0900
commited25d77e109b1c90e999e77f51f00b6bf6b75bae (patch)
tree1d549b8e993b9ae388d25be076187acd21d36641
parent33730250bc0b5d432e7fb37e5a95ff77e10e1364 (diff)
downloadlinux-linaro-stable-ed25d77e109b1c90e999e77f51f00b6bf6b75bae.tar.gz
USB: cdc_acm: Fix oops when Droids MuIn LCD is connected
commit fd5054c169d29747a44b4e1419ff47f57ae82dbc upstream. The Droids MuIn LCD operates like a serial remote terminal. Data received are displayed directly on the LCD. This patch fixes the kernel null pointer oops when it is plugged in. Add NO_DATA_INTERFACE quirk to tell the driver that "control" and "data" interfaces are not separated for this device, which prevents dereferencing a null pointer in the device probe code. Signed-off-by: Erik Slagter <erik@slagter.name> Signed-off-by: Maxin B. John <maxin.john@gmail.com> Tested-by: Erik Slagter <erik@slagter.name> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/class/cdc-acm.c13
-rw-r--r--drivers/usb/class/cdc-acm.h1
2 files changed, 12 insertions, 2 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 30bb8d053c2e..83589f49efde 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -946,7 +946,7 @@ static int acm_probe(struct usb_interface *intf,
u8 ac_management_function = 0;
u8 call_management_function = 0;
int call_interface_num = -1;
- int data_interface_num;
+ int data_interface_num = -1;
unsigned long quirks;
int num_rx_buf;
int i;
@@ -1030,7 +1030,11 @@ next_desc:
if (!union_header) {
if (call_interface_num > 0) {
dev_dbg(&intf->dev, "No union descriptor, using call management descriptor\n");
- data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
+ /* quirks for Droids MuIn LCD */
+ if (quirks & NO_DATA_INTERFACE)
+ data_interface = usb_ifnum_to_if(usb_dev, 0);
+ else
+ data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
control_interface = intf;
} else {
if (intf->cur_altsetting->desc.bNumEndpoints != 3) {
@@ -1622,6 +1626,11 @@ static const struct usb_device_id acm_ids[] = {
.driver_info = NOT_A_MODEM,
},
+ /* Support for Droids MuIn LCD */
+ { USB_DEVICE(0x04d8, 0x000b),
+ .driver_info = NO_DATA_INTERFACE,
+ },
+
/* control interfaces without any protocol set */
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_PROTO_NONE) },
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index 5eeb570b9a61..a2446d6caf05 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -137,3 +137,4 @@ struct acm {
#define SINGLE_RX_URB 2
#define NO_CAP_LINE 4
#define NOT_A_MODEM 8
+#define NO_DATA_INTERFACE 16