Dec 22 2012

[SCSI] bnx2fc: Remove potential NULL dereference 

Author: Julia Lawall <Julia.Lawall@lip6.fr>

If the NULL test is necessary, the initialization involving a dereference of
the tested value should be moved after the NULL test.

The sematic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
type T;
expression E;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
  ... when != E
      when != i
  if (E == NULL) S
+ i = E->fld;
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Bhanu Prakash Gollapudi 
Signed-off-by: James Bottomley 

---
 drivers/scsi/bnx2fc/bnx2fc_io.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
 
diff --git a/drivers/scsi/bnx2fc/bnx2fc_io.c b/drivers/scsi/bnx2fc/bnx2fc_io.c
index 8d4626c..c661ccd 100644
--- a/drivers/scsi/bnx2fc/bnx2fc_io.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_io.c
@@ -685,8 +685,8 @@ int bnx2fc_init_mp_req(struct bnx2fc_cmd *io_req)
 static int bnx2fc_initiate_tmf(struct scsi_cmnd *sc_cmd, u8 tm_flags)
 {
 	struct fc_lport *lport;
-	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
-	struct fc_rport_libfc_priv *rp = rport->dd_data;
+	struct fc_rport *rport;
+	struct fc_rport_libfc_priv *rp;
 	struct fcoe_port *port;
 	struct bnx2fc_interface *interface;
 	struct bnx2fc_rport *tgt;
@@ -704,6 +704,7 @@ static int bnx2fc_initiate_tmf(struct scsi_cmnd *sc_cmd, u8 tm_flags)
 	unsigned long start = jiffies;
 
 	lport = shost_priv(host);
+	rport = starget_to_rport(scsi_target(sc_cmd->device));
 	port = lport_priv(lport);
 	interface = port->priv;
 
@@ -712,6 +713,7 @@ static int bnx2fc_initiate_tmf(struct scsi_cmnd *sc_cmd, u8 tm_flags)
 		rc = FAILED;
 		goto tmf_err;
 	}
+	rp = rport->dd_data;
 
 	rc = fc_block_scsi_eh(sc_cmd);
 	if (rc)

qlambert