[PATCH 62/74] udldrmfb: udl_get_edid: usb_control_msg buffer must not be on the stack

From: Herton Ronaldo Krzesinski
Date: Wed Jan 23 2013 - 22:32:02 EST


3.5.7.4 -stable review patch. If anyone has any objections, please let me know.

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

From: Hans de Goede <hdegoede@xxxxxxxxxx>

commit 242187b362555849e8c971dfbbfd55f8bd9fa717 upstream.

The buffer passed to usb_control_msg may end up in scatter-gather list, and
may thus not be on the stack. Having it on the stack usually works on x86, but
not on other archs.

Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx>
---
drivers/gpu/drm/udl/udl_connector.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/udl/udl_connector.c b/drivers/gpu/drm/udl/udl_connector.c
index 1230bc0..b7780dd 100644
--- a/drivers/gpu/drm/udl/udl_connector.c
+++ b/drivers/gpu/drm/udl/udl_connector.c
@@ -22,13 +22,17 @@
static u8 *udl_get_edid(struct udl_device *udl)
{
u8 *block;
- char rbuf[3];
+ char *rbuf;
int ret, i;

block = kmalloc(EDID_LENGTH, GFP_KERNEL);
if (block == NULL)
return NULL;

+ rbuf = kmalloc(2, GFP_KERNEL);
+ if (rbuf == NULL)
+ goto error;
+
for (i = 0; i < EDID_LENGTH; i++) {
ret = usb_control_msg(udl->ddev->usbdev,
usb_rcvctrlpipe(udl->ddev->usbdev, 0), (0x02),
@@ -42,10 +46,12 @@ static u8 *udl_get_edid(struct udl_device *udl)
block[i] = rbuf[1];
}

+ kfree(rbuf);
return block;

error:
kfree(block);
+ kfree(rbuf);
return NULL;
}

--
1.7.9.5

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