Re: [PATCH] net: qrtr: fix another OOB Read in qrtr_endpoint_post
From: Jakub Kicinski <kuba@kernel.org>
Date: 2021-08-19 19:16:34
Also in:
linux-arm-msm, lkml
On Fri, 20 Aug 2021 02:14:58 +0800 butt3rflyh4ck wrote:
From: butt3rflyh4ck <redacted>
This check was incomplete, did not consider size is 0:
if (len != ALIGN(size, 4) + hdrlen)
goto err;
if size from qrtr_hdr is 0, the result of ALIGN(size, 4)
will be 0, In case of len == hdrlen and size == 0
in header this check won't fail and
if (cb->type == QRTR_TYPE_NEW_SERVER) {
/* Remote node endpoint can bridge other distant nodes */
const struct qrtr_ctrl_pkt *pkt = data + hdrlen;
qrtr_node_assign(node, le32_to_cpu(pkt->server.node));
}
will also read out of bound from data, which is hdrlen allocated block.
Fixes: 194ccc88297a ("net: qrtr: Support decoding incoming v2 packets")
Fixes: ad9d24c9429e ("net: qrtr: fix OOB Read in qrtr_endpoint_post")Please make sure to CC authors of patches which are under Fixes, they are usually the best people to review the patch. Adding them now.
Signed-off-by: butt3rflyh4ck <redacted>
We'll need your name. AFAIU it's because of Developer Certificate of Origin. You'll need to resend with this fixed (and please remember the CCs).
quoted hunk ↗ jump to hunk
diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c index 171b7f3be6ef..0c30908628ba 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 (len != ALIGN(size, 4) + hdrlen) + if (!size || len != ALIGN(size, 4) + hdrlen) goto err; if (cb->dst_port != QRTR_PORT_CTRL && cb->type != QRTR_TYPE_DATA &&