From: Chris Leech Date: Tue, 23 Feb 2021 21:39:01 -0800 Subject: scsi: iscsi: Verify lengths on passthrough PDUs Git-commit: f9dbdf97a5bd92b1a49cee3d591b55b11fd7a6d5 References: CVE-2021-27365 bsc#1182715 Patch-mainline: v5.12-rc2 Open-iSCSI sends passthrough PDUs over netlink, but the kernel should be verifying that the provided PDU header and data lengths fall within the netlink message to prevent accessing beyond that in memory. Cc: stable@vger.kernel.org Reported-by: Adam Nichols Reviewed-by: Lee Duncan Reviewed-by: Mike Christie Signed-off-by: Chris Leech Signed-off-by: Martin K. Petersen Acked-by: Lee Duncan --- drivers/scsi/scsi_transport_iscsi.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -3555,6 +3555,7 @@ iscsi_if_recv_msg(struct sk_buff *skb, s { int err = 0; u32 portid; + u32 pdu_len; struct iscsi_uevent *ev = nlmsg_data(nlh); struct iscsi_transport *transport = NULL; struct iscsi_internal *priv; @@ -3670,6 +3671,14 @@ iscsi_if_recv_msg(struct sk_buff *skb, s err = -EINVAL; break; case ISCSI_UEVENT_SEND_PDU: + pdu_len = nlh->nlmsg_len - sizeof(*nlh) - sizeof(*ev); + + if ((ev->u.send_pdu.hdr_size > pdu_len) || + (ev->u.send_pdu.data_size > (pdu_len - ev->u.send_pdu.hdr_size))) { + err = -EINVAL; + break; + } + conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid); if (conn) ev->r.retcode = transport->send_pdu(conn,