From: Dan Carpenter Date: Mon, 30 Aug 2021 08:37:17 +0000 (+0300) Subject: net: qrtr: make checks in qrtr_endpoint_post() stricter X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=aaa8e4922c887ff47ad66ef918193682bccc1905;p=linux.git net: qrtr: make checks in qrtr_endpoint_post() stricter 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 Signed-off-by: David S. Miller --- diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c index b8508e35d20eb..525e3ea063b14 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)); }