scsi: qla2xxx: Fix mem access after free

System crash, where driver is accessing scsi layer's
memory (scsi_cmnd->device->host) to search for a well known internal
pointer (vha). The scsi_cmnd was released back to upper layer which
could be freed, but the driver is still accessing it.

7 [ffffa8e8d2c3f8d0] page_fault at ffffffff86c010fe
  [exception RIP: __qla2x00_eh_wait_for_pending_commands+240]
  RIP: ffffffffc0642350  RSP: ffffa8e8d2c3f988  RFLAGS: 00010286
  RAX: 0000000000000165  RBX: 0000000000000002  RCX: 00000000000036d8
  RDX: 0000000000000000  RSI: ffff9c5c56535188  RDI: 0000000000000286
  RBP: ffff9c5bf7aa4a58   R8: ffff9c589aecdb70   R9: 00000000000003d1
  R10: 0000000000000001  R11: 0000000000380000 R12: ffff9c5c5392bc78
  R13: ffff9c57044ff5c0 R14: ffff9c56b5a3aa00  R15: 00000000000006db
  ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
8 [ffffa8e8d2c3f9c8] qla2x00_eh_wait_for_pending_commands at ffffffffc0646dd5 [qla2xxx]
9 [ffffa8e8d2c3fa00] __qla2x00_async_tm_cmd at ffffffffc0658094 [qla2xxx]

Remove access of freed memory. Currently the driver was checking to see if
scsi_done was called by seeing if the sp->type has changed. Instead,
check to see if the command has left the  oustanding_cmds[] array as
sign of scsi_done was called.

Cc: stable@vger.kernel.org
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Link: https://lore.kernel.org/r/20230428075339.32551-6-njavali@marvell.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 64 insertions, 66 deletions

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 2fa695bf38b7..bc89d3da8fd0 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -1079,43 +1079,6 @@ qc24_fail_command:
 }
 
 /*
- * qla2x00_eh_wait_on_command
- *    Waits for the command to be returned by the Firmware for some
- *    max time.
- *
- * Input:
- *    cmd = Scsi Command to wait on.
- *
- * Return:
- *    Completed in time : QLA_SUCCESS
- *    Did not complete in time : QLA_FUNCTION_FAILED
- */
-static int
-qla2x00_eh_wait_on_command(struct scsi_cmnd *cmd)
-{
-#define ABORT_POLLING_PERIOD	1000
-#define ABORT_WAIT_ITER		((2 * 1000) / (ABORT_POLLING_PERIOD))
-	unsigned long wait_iter = ABORT_WAIT_ITER;
-	scsi_qla_host_t *vha = shost_priv(cmd->device->host);
-	struct qla_hw_data *ha = vha->hw;
-	srb_t *sp = scsi_cmd_priv(cmd);
-	int ret = QLA_SUCCESS;
-
-	if (unlikely(pci_channel_offline(ha->pdev)) || ha->flags.eeh_busy) {
-		ql_dbg(ql_dbg_taskm, vha, 0x8005,
-		    "Return:eh_wait.\n");
-		return ret;
-	}
-
-	while (sp->type && wait_iter--)
-		msleep(ABORT_POLLING_PERIOD);
-	if (sp->type)
-		ret = QLA_FUNCTION_FAILED;
-
-	return ret;
-}
-
-/*
  * qla2x00_wait_for_hba_online
  *    Wait till the HBA is online after going through
  *    <= MAX_RETRIES_OF_ISP_ABORT  or
@@ -1365,6 +1328,9 @@ qla2xxx_eh_abort(struct scsi_cmnd *cmd)
 	return ret;
 }
 
+#define ABORT_POLLING_PERIOD	1000
+#define ABORT_WAIT_ITER		((2 * 1000) / (ABORT_POLLING_PERIOD))
+
 /*
  * Returns: QLA_SUCCESS or QLA_FUNCTION_FAILED.
  */
@@ -1378,41 +1344,73 @@ __qla2x00_eh_wait_for_pending_commands(struct qla_qpair *qpair, unsigned int t,
 	struct req_que *req = qpair->req;
 	srb_t *sp;
 	struct scsi_cmnd *cmd;
+	unsigned long wait_iter = ABORT_WAIT_ITER;
+	bool found;
+	struct qla_hw_data *ha = vha->hw;
 
 	status = QLA_SUCCESS;
 
-	spin_lock_irqsave(qpair->qp_lock_ptr, flags);
-	for (cnt = 1; status == QLA_SUCCESS &&
-		cnt < req->num_outstanding_cmds; cnt++) {
-		sp = req->outstanding_cmds[cnt];
-		if (!sp)
-			continue;
-		if (sp->type != SRB_SCSI_CMD)
-			continue;
-		if (vha->vp_idx != sp->vha->vp_idx)
-			continue;
-		match = 0;
-		cmd = GET_CMD_SP(sp);
-		switch (type) {
-		case WAIT_HOST:
-			match = 1;
-			break;
-		case WAIT_TARGET:
-			match = cmd->device->id == t;
-			break;
-		case WAIT_LUN:
-			match = (cmd->device->id == t &&
-				cmd->device->lun == l);
-			break;
-		}
-		if (!match)
-			continue;
+	while (wait_iter--) {
+		found = false;
 
-		spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
-		status = qla2x00_eh_wait_on_command(cmd);
 		spin_lock_irqsave(qpair->qp_lock_ptr, flags);
+		for (cnt = 1; cnt < req->num_outstanding_cmds; cnt++) {
+			sp = req->outstanding_cmds[cnt];
+			if (!sp)
+				continue;
+			if (sp->type != SRB_SCSI_CMD)
+				continue;
+			if (vha->vp_idx != sp->vha->vp_idx)
+				continue;
+			match = 0;
+			cmd = GET_CMD_SP(sp);
+			switch (type) {
+			case WAIT_HOST:
+				match = 1;
+				break;
+			case WAIT_TARGET:
+				if (sp->fcport)
+					match = sp->fcport->d_id.b24 == t;
+				else
+					match = 0;
+				break;
+			case WAIT_LUN:
+				if (sp->fcport)
+					match = (sp->fcport->d_id.b24 == t &&
+						cmd->device->lun == l);
+				else
+					match = 0;
+				break;
+			}
+			if (!match)
+				continue;
+
+			spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
+
+			if (unlikely(pci_channel_offline(ha->pdev)) ||
+			    ha->flags.eeh_busy) {
+				ql_dbg(ql_dbg_taskm, vha, 0x8005,
+				    "Return:eh_wait.\n");
+				return status;
+			}
+
+			/*
+			 * SRB_SCSI_CMD is still in the outstanding_cmds array.
+			 * it means scsi_done has not called. Wait for it to
+			 * clear from outstanding_cmds.
+			 */
+			msleep(ABORT_POLLING_PERIOD);
+			spin_lock_irqsave(qpair->qp_lock_ptr, flags);
+			found = true;
+		}
+		spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
+
+		if (!found)
+			break;
 	}
-	spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
+
+	if (!wait_iter && found)
+		status = QLA_FUNCTION_FAILED;
 
 	return status;
 }