[PATCH 2/3] udldrmfb: udl_get_edid: usb_control_msg buffer must not be on the stack

Hans de Goede hdegoede at redhat.com
Fri Jan 11 03:08:57 PST 2013


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 at redhat.com>
---
 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 86538c9..a8c76f4 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;
 }
 
-- 
1.8.0.2



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