From 679fcae46c8b2352bba3485d521da070cfbe68e6 Mon Sep 17 00:00:00 2001
From: Laura Abbott <labbott@redhat.com>
Date: Tue, 4 Sep 2018 11:47:40 -0700
Subject: [PATCH 1/2] scsi: iscsi: target: Don't use stack buffer for
 scatterlist

Fedora got a bug report of a crash with iSCSI:

kernel BUG at include/linux/scatterlist.h:143!
...
RIP: 0010:iscsit_do_crypto_hash_buf+0x154/0x180 [iscsi_target_mod]
...
 Call Trace:
  ? iscsi_target_tx_thread+0x200/0x200 [iscsi_target_mod]
  iscsit_get_rx_pdu+0x4cd/0xa90 [iscsi_target_mod]
  ? native_sched_clock+0x3e/0xa0
  ? iscsi_target_tx_thread+0x200/0x200 [iscsi_target_mod]
  iscsi_target_rx_thread+0x81/0xf0 [iscsi_target_mod]
  kthread+0x120/0x140
  ? kthread_create_worker_on_cpu+0x70/0x70
  ret_from_fork+0x3a/0x50

This is a BUG_ON for using a stack buffer with a scatterlist.  There
are two cases that trigger this bug. Switch to using a dynamically
allocated buffer for one case and do not assign a NULL buffer in
another case.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 drivers/target/iscsi/iscsi_target.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 9cdfccbdd06ff..cc756a123fd8c 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1416,7 +1416,8 @@ static void iscsit_do_crypto_hash_buf(struct ahash_request *hash,
 
 	sg_init_table(sg, ARRAY_SIZE(sg));
 	sg_set_buf(sg, buf, payload_length);
-	sg_set_buf(sg + 1, pad_bytes, padding);
+	if (padding)
+		sg_set_buf(sg + 1, pad_bytes, padding);
 
 	ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
 
@@ -3910,10 +3911,14 @@ static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
 static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
 {
 	int ret;
-	u8 buffer[ISCSI_HDR_LEN], opcode;
+	u8 *buffer, opcode;
 	u32 checksum = 0, digest = 0;
 	struct kvec iov;
 
+	buffer = kcalloc(ISCSI_HDR_LEN, sizeof(*buffer), GFP_KERNEL);
+	if (!buffer)
+		return;
+
 	while (!kthread_should_stop()) {
 		/*
 		 * Ensure that both TX and RX per connection kthreads
@@ -3921,7 +3926,6 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
 		 */
 		iscsit_thread_check_cpumask(conn, current, 0);
 
-		memset(buffer, 0, ISCSI_HDR_LEN);
 		memset(&iov, 0, sizeof(struct kvec));
 
 		iov.iov_base	= buffer;
@@ -3930,7 +3934,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
 		ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
 		if (ret != ISCSI_HDR_LEN) {
 			iscsit_rx_thread_wait_for_tcp(conn);
-			return;
+			break;
 		}
 
 		if (conn->conn_ops->HeaderDigest) {
@@ -3940,7 +3944,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
 			ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
 			if (ret != ISCSI_CRC_LEN) {
 				iscsit_rx_thread_wait_for_tcp(conn);
-				return;
+				break;
 			}
 
 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, buffer,
@@ -3964,7 +3968,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
 		}
 
 		if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
-			return;
+			break;
 
 		opcode = buffer[0] & ISCSI_OPCODE_MASK;
 
@@ -3975,13 +3979,15 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
 			" while in Discovery Session, rejecting.\n", opcode);
 			iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
 					  buffer);
-			return;
+			break;
 		}
 
 		ret = iscsi_target_rx_opcode(conn, buffer);
 		if (ret < 0)
-			return;
+			break;
 	}
+
+	kfree(buffer);
 }
 
 int iscsi_target_rx_thread(void *arg)

From cbe3fd39d223f14b1c60c80fe9347a3dd08c2edb Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Sat, 8 Sep 2018 11:42:27 +0300
Subject: [PATCH 2/2] scsi: qla2xxx: Fix an endian bug in fcpcmd_is_corrupted()

We should first do the le16_to_cpu endian conversion and then apply the
FCP_CMD_LENGTH_MASK mask.

Fixes: 5f35509db179 ("qla2xxx: Terminate exchange if corrupted")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Quinn Tran <Quinn.Tran@cavium.com>
Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 drivers/scsi/qla2xxx/qla_target.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.h b/drivers/scsi/qla2xxx/qla_target.h
index fecf96f0225c6..199d3ba1916d5 100644
--- a/drivers/scsi/qla2xxx/qla_target.h
+++ b/drivers/scsi/qla2xxx/qla_target.h
@@ -374,8 +374,8 @@ struct atio_from_isp {
 static inline int fcpcmd_is_corrupted(struct atio *atio)
 {
 	if (atio->entry_type == ATIO_TYPE7 &&
-	    (le16_to_cpu(atio->attr_n_length & FCP_CMD_LENGTH_MASK) <
-	    FCP_CMD_LENGTH_MIN))
+	    ((le16_to_cpu(atio->attr_n_length) & FCP_CMD_LENGTH_MASK) <
+	     FCP_CMD_LENGTH_MIN))
 		return 1;
 	else
 		return 0;