1 files changed, 15 insertions, 9 deletions

diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 065149e84f42..ebce994ab0b7 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2008 Red Hat, Inc.  All rights reserved.
+ * Copyright (C) 2006-2009 Red Hat, Inc.  All rights reserved.
  *
  * This copyrighted material is made available to anyone wishing to use,
  * modify, copy, or redistribute it subject to the terms and conditions
@@ -84,7 +84,7 @@ struct dlm_lock_result32 {
 
 static void compat_input(struct dlm_write_request *kb,
                          struct dlm_write_request32 *kb32,
-                         size_t count)
+                         int namelen)
 {
         kb->version[0] = kb32->version[0];
         kb->version[1] = kb32->version[1];
@@ -96,8 +96,7 @@ static void compat_input(struct dlm_write_request *kb,
             kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
                 kb->i.lspace.flags = kb32->i.lspace.flags;
                 kb->i.lspace.minor = kb32->i.lspace.minor;
-                memcpy(kb->i.lspace.name, kb32->i.lspace.name, count -
-                        offsetof(struct dlm_write_request32, i.lspace.name));
+                memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
         } else if (kb->cmd == DLM_USER_PURGE) {
                 kb->i.purge.nodeid = kb32->i.purge.nodeid;
                 kb->i.purge.pid = kb32->i.purge.pid;
@@ -115,8 +114,7 @@ static void compat_input(struct dlm_write_request *kb,
                 kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr;
                 kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb;
                 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
-                memcpy(kb->i.lock.name, kb32->i.lock.name, count -
-                        offsetof(struct dlm_write_request32, i.lock.name));
+                memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
         }
 }
 
@@ -539,9 +537,16 @@ static ssize_t device_write(struct file *file, const char __user *buf,
 #ifdef CONFIG_COMPAT
         if (!kbuf->is64bit) {
                 struct dlm_write_request32 *k32buf;
+                int namelen = 0;
+
+                if (count > sizeof(struct dlm_write_request32))
+                        namelen = count - sizeof(struct dlm_write_request32);
+
                 k32buf = (struct dlm_write_request32 *)kbuf;
-                kbuf = kmalloc(count + 1 + (sizeof(struct dlm_write_request) -
-                               sizeof(struct dlm_write_request32)), GFP_KERNEL);
+
+                /* add 1 after namelen so that the name string is terminated */
+                kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
+                               GFP_KERNEL);
                 if (!kbuf) {
                         kfree(k32buf);
                         return -ENOMEM;
@@ -549,7 +554,8 @@ static ssize_t device_write(struct file *file, const char __user *buf,
 
                 if (proc)
                         set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
-                compat_input(kbuf, k32buf, count + 1);
+
+                compat_input(kbuf, k32buf, namelen);
                 kfree(k32buf);
         }
 #endif