usb_control_msg initiates (and waits for completion of) a dma transfer using
the supplied buffer. That buffer thus has to be seperately allocated on
the heap.
In lib/dma_debug.c the function check_for_stack even warns about it:
WARNING: at lib/dma-debug.c:866 check_for_stack
Tested-By: Malcolm Priestley <tvboxspy@xxxxxxxxx>
Signed-off-by: Florian Mickler <florian@xxxxxxxxxxx>
---
[v2: fix use after free as noted by Malcom]
drivers/media/dvb/dvb-usb/lmedm04.c | 19 +++++++++++++++----
1 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/media/dvb/dvb-usb/lmedm04.c b/drivers/media/dvb/dvb-usb/lmedm04.c
index 0a3e88f..8a79354 100644
--- a/drivers/media/dvb/dvb-usb/lmedm04.c
+++ b/drivers/media/dvb/dvb-usb/lmedm04.c
@@ -314,13 +314,19 @@ static int lme2510_int_read(struct dvb_usb_adapter *adap)
static int lme2510_return_status(struct usb_device *dev)
{
int ret = 0;
- u8 data[10] = {0};
+ u8 *data;
+
+ data = kzalloc(10, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
ret |= usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
0x06, 0x80, 0x0302, 0x00, data, 0x0006, 200);
info("Firmware Status: %x (%x)", ret , data[2]);
- return (ret < 0) ? -ENODEV : data[2];
+ ret = (ret < 0) ? -ENODEV : data[2];
+ kfree(data);
+ return ret;
}
static int lme2510_msg(struct dvb_usb_device *d,
@@ -603,7 +609,7 @@ static int lme2510_download_firmware(struct usb_device *dev,
const struct firmware *fw)
{
int ret = 0;
- u8 data[512] = {0};
+ u8 *data;
u16 j, wlen, len_in, start, end;
u8 packet_size, dlen, i;
u8 *fw_data;
@@ -611,6 +617,11 @@ static int lme2510_download_firmware(struct usb_device *dev,
packet_size = 0x31;
len_in = 1;
+ data = kzalloc(512, GFP_KERNEL);
+ if (!data) {
+ info("FRM Could not start Firmware Download (Buffer allocation failed)");
+ return -ENOMEM;
+ }
info("FRM Starting Firmware Download");
@@ -654,7 +665,7 @@ static int lme2510_download_firmware(struct usb_device *dev,
else
info("FRM Firmware Download Completed - Resetting Device");
-
+ kfree(data);
return (ret < 0) ? -ENODEV : 0;
}
--
1.7.4.1
--
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