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>
diff --git a/drivers/hid/hid-picolcd.c b/drivers/hid/hid-picolcd.c
index 95253b3..7aabf65 100644
--- a/drivers/hid/hid-picolcd.c
+++ b/drivers/hid/hid-picolcd.c
@@ -1616,7 +1616,7 @@
raw_data[len_off] = s > 32 ? 32 : s;
if (copy_from_user(raw_data+len_off+1, u, raw_data[len_off])) {
err = -EFAULT;
- goto skip;
+ break;
}
resp = picolcd_send_and_wait(data->hdev, report_id, raw_data,
len_off+1+raw_data[len_off]);