From 5b6fafb3f51abd8cbce5d74e3edf364734d72379 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 30 Jun 2016 17:49:53 -0600
Subject: [PATCH] Several MTD FLASH drivers nullify the freed 'priv' structure
 and failed to return NULL as stated in the comments.  Result, will operate on
 a NULL pointer later.  Noted by David Sidrane.

---
 drivers/mtd/at25.c    | 2 +-
 drivers/mtd/is25xp.c  | 3 +--
 drivers/mtd/m25px.c   | 2 +-
 drivers/mtd/ramtron.c | 2 +-
 drivers/mtd/sst25.c   | 2 +-
 drivers/mtd/sst25xx.c | 2 +-
 drivers/mtd/sst26.c   | 2 +-
 drivers/mtd/w25.c     | 2 +-
 8 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/at25.c b/drivers/mtd/at25.c
index efc2e355a7..777ff3877f 100644
--- a/drivers/mtd/at25.c
+++ b/drivers/mtd/at25.c
@@ -673,7 +673,7 @@ FAR struct mtd_dev_s *at25_initialize(FAR struct spi_dev_s *dev)
 
           ferr("ERROR: Unrecognized\n");
           kmm_free(priv);
-          priv = NULL;
+          return NULL;
         }
       else
         {
diff --git a/drivers/mtd/is25xp.c b/drivers/mtd/is25xp.c
index 2228f760b0..55b677b38a 100644
--- a/drivers/mtd/is25xp.c
+++ b/drivers/mtd/is25xp.c
@@ -978,7 +978,7 @@ FAR struct mtd_dev_s *is25xp_initialize(FAR struct spi_dev_s *dev)
 
           ferr("ERROR: Unrecognized\n");
           kmm_free(priv);
-          priv = NULL;
+          return NULL;
         }
       else
         {
@@ -999,4 +999,3 @@ FAR struct mtd_dev_s *is25xp_initialize(FAR struct spi_dev_s *dev)
   finfo("Return %p\n", priv);
   return (FAR struct mtd_dev_s *)priv;
 }
-
diff --git a/drivers/mtd/m25px.c b/drivers/mtd/m25px.c
index eb2cade8ee..4402995afb 100644
--- a/drivers/mtd/m25px.c
+++ b/drivers/mtd/m25px.c
@@ -1033,7 +1033,7 @@ FAR struct mtd_dev_s *m25p_initialize(FAR struct spi_dev_s *dev)
 
           ferr("ERROR: Unrecognized\n");
           kmm_free(priv);
-          priv = NULL;
+          return NULL;
         }
     }
 
diff --git a/drivers/mtd/ramtron.c b/drivers/mtd/ramtron.c
index a81469f92e..0152475b98 100644
--- a/drivers/mtd/ramtron.c
+++ b/drivers/mtd/ramtron.c
@@ -826,7 +826,7 @@ FAR struct mtd_dev_s *ramtron_initialize(FAR struct spi_dev_s *dev)
           /* Unrecognized! Discard all of that work we just did and return NULL */
 
           kmm_free(priv);
-          priv = NULL;
+          return NULL;
         }
     }
 
diff --git a/drivers/mtd/sst25.c b/drivers/mtd/sst25.c
index 89d21324aa..8da5778d84 100644
--- a/drivers/mtd/sst25.c
+++ b/drivers/mtd/sst25.c
@@ -1208,7 +1208,7 @@ FAR struct mtd_dev_s *sst25_initialize(FAR struct spi_dev_s *dev)
 
           ferr("ERROR: Unrecognized\n");
           kmm_free(priv);
-          priv = NULL;
+          return NULL;
         }
       else
         {
diff --git a/drivers/mtd/sst25xx.c b/drivers/mtd/sst25xx.c
index 4d30be50bb..9f883483af 100644
--- a/drivers/mtd/sst25xx.c
+++ b/drivers/mtd/sst25xx.c
@@ -956,7 +956,7 @@ FAR struct mtd_dev_s *sst25xx_initialize(FAR struct spi_dev_s *dev)
 
           ferr("ERROR: Unrecognized\n");
           kmm_free(priv);
-          priv = NULL;
+          return NULL;
         }
       else
         {
diff --git a/drivers/mtd/sst26.c b/drivers/mtd/sst26.c
index 91eb045fcf..51888da063 100644
--- a/drivers/mtd/sst26.c
+++ b/drivers/mtd/sst26.c
@@ -934,7 +934,7 @@ FAR struct mtd_dev_s *sst26_initialize_spi(FAR struct spi_dev_s *dev)
 
           ssterr("ERROR: Unrecognized\n");
           kmm_free(priv);
-          priv = NULL;
+          return NULL;
         }
       else
         {
diff --git a/drivers/mtd/w25.c b/drivers/mtd/w25.c
index 3559f8d6a5..da015a8c42 100644
--- a/drivers/mtd/w25.c
+++ b/drivers/mtd/w25.c
@@ -1258,7 +1258,7 @@ FAR struct mtd_dev_s *w25_initialize(FAR struct spi_dev_s *spi)
 
           ferr("ERROR: Unrecognized\n");
           kmm_free(priv);
-          priv = NULL;
+          return NULL;
         }
       else
         {