These checks are still not strict enough. The main problem is that if
"cb->type == QRTR_TYPE_NEW_SERVER" is true then "len - hdrlen" is
guaranteed to be 4 but we need to be at least 16 bytes. In fact, we
can reject everything smaller than sizeof(*pkt) which is 20 bytes.
Also I don't like the ALIGN(size, 4). It's better to just insist that
data is needs to be aligned at the start.
Fixes: 0baa99ee353c ("net: qrtr: Allow non-immediate node routing")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
This was from review. Not tested.
net/qrtr/qrtr.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index b8508e35d20e..dbb647f5481b 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -493,7 +493,7 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
goto err;
}
- if (!size || len != ALIGN(size, 4) + hdrlen)
+ if (!size || size % 3 || len != size + hdrlen)
goto err;
if (cb->dst_port != QRTR_PORT_CTRL && cb->type != QRTR_TYPE_DATA &&
@@ -506,8 +506,12 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
if (cb->type == QRTR_TYPE_NEW_SERVER) {
/* Remote node endpoint can bridge other distant nodes */
- const struct qrtr_ctrl_pkt *pkt = data + hdrlen;
+ const struct qrtr_ctrl_pkt *pkt;
+ if (size < sizeof(*pkt))
+ goto err;
+
+ pkt = data + hdrlen;
qrtr_node_assign(node, le32_to_cpu(pkt->server.node));
}
--
2.20.1
