reader: more meaningful null pointer check in get_sw
At the moment msgb_apdu_de(resp) is used to check if the msgb that is
handed over to get_sw is properly populated with data.
However, since msgb_apdu_de() is just adding an offset, which cannot be
0 to ->l2h the returned value also can never be NULL. This means that we
cannot use msgb_apdu_de() to detect if resp contains a nullpointer.
Lets check if ->l2h is not NULL instead. This will make sure that ->l2h
is populated.
Change-Id: I32bc56c9264c01911a4f4b4f911b09e955205010
Related: OS#5560
diff --git a/src/sim/reader.c b/src/sim/reader.c
index b41b730..982b2ee 100644
--- a/src/sim/reader.c
+++ b/src/sim/reader.c
@@ -40,7 +40,7 @@
{
int ret;
- if (!msgb_apdu_de(resp) || msgb_apdu_le(resp) < 2)
+ if (!resp->l2h || msgb_apdu_le(resp) < 2)
return -EIO;
ret = msgb_get_u16(resp);