staging: dgrp: check for NULL pointer in (un)register_proc_table

register_proc_table and unregister_proc_table didn't deal with the
possibility that the *table pointer could be NULL.  Check for this and
return if table is NULL.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/staging/dgrp/dgrp_specproc.c b/drivers/staging/dgrp/dgrp_specproc.c
index a5840e7d6665..24327c3bad83 100644
--- a/drivers/staging/dgrp/dgrp_specproc.c
+++ b/drivers/staging/dgrp/dgrp_specproc.c
@@ -229,6 +229,9 @@ static void register_proc_table(struct dgrp_proc_entry *table,
         int len;
         mode_t mode;
 
+        if (table == NULL)
+                return;
+
         for (; table->id; table++) {
                 /* Can't do anything without a proc name. */
                 if (!table->name)
@@ -297,6 +300,9 @@ static void unregister_proc_table(struct dgrp_proc_entry *table,
         struct proc_dir_entry *de;
         struct nd_struct *tmp;
 
+        if (table == NULL)
+                return;
+
         list_for_each_entry(tmp, &nd_struct_list, list) {
                 if ((table == dgrp_net_table) && (tmp->nd_net_de)) {
                         unregister_dgrp_device(tmp->nd_net_de);