Commit aeacb6fd authored May 15, 2010 by Julia Lawall Committed by Jiri Kosina May 17, 2010

HID: picolcd: Eliminate use after free

The skip label frees resp, which has not been allocated at the point of
this goto and then does a break, based on the fact that err is non-zero.
This is replaced by a break directly.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/

)

// <smpl>
@free@
expression E;
position p;
@@
kfree@p(E)

@@
expression free.E, subE<=free.E, E1;
position free.p;
@@

  kfree@p(E)
  ...
(
  subE = E1
|
* E
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

parent 9d71ea05

drivers/hid/hid-picolcd.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -1616,7 +1616,7 @@ static ssize_t _picolcd_flash_write(struct picolcd_data *data, int report_id,
	raw_data[len_off] = s > 32 ? 32 : s;		raw_data[len_off] = s > 32 ? 32 : s;
	if (copy_from_user(raw_data+len_off+1, u, raw_data[len_off])) {		if (copy_from_user(raw_data+len_off+1, u, raw_data[len_off])) {
	err = -EFAULT;		err = -EFAULT;
	goto skip;		break;
	}		}
	resp = picolcd_send_and_wait(data->hdev, report_id, raw_data,		resp = picolcd_send_and_wait(data->hdev, report_id, raw_data,
	len_off+1+raw_data[len_off]);		len_off+1+raw_data[len_off]);