mptfusion: use memdup_user

Let memdup_user handle the kmalloc, copy_from_user and error checking
kfree code.

Spotted by the following smatch (false positive) warning:

  drivers/message/fusion/mptctl.c:1369 mptctl_getiocinfo() warn:
    possible info leak 'karg'

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 5 insertions, 13 deletions

diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c
index 8a050e885688..b0a892a2bf1b 100644
--- a/drivers/message/fusion/mptctl.c
+++ b/drivers/message/fusion/mptctl.c
@@ -1261,19 +1261,11 @@ mptctl_getiocinfo (unsigned long arg, unsigned int data_size)
         else
                 return -EFAULT;
 
-        karg = kmalloc(data_size, GFP_KERNEL);
-        if (karg == NULL) {
-                printk(KERN_ERR MYNAM "%s::mpt_ioctl_iocinfo() @%d - no memory available!\n",
-                                __FILE__, __LINE__);
-                return -ENOMEM;
-        }
-
-        if (copy_from_user(karg, uarg, data_size)) {
-                printk(KERN_ERR MYNAM "%s@%d::mptctl_getiocinfo - "
-                        "Unable to read in mpt_ioctl_iocinfo struct @ %p\n",
-                                __FILE__, __LINE__, uarg);
-                kfree(karg);
-                return -EFAULT;
+        karg = memdup_user(uarg, data_size);
+        if (IS_ERR(karg)) {
+                printk(KERN_ERR MYNAM "%s@%d::mpt_ioctl_iocinfo() - memdup_user returned error [%ld]\n",
+                                __FILE__, __LINE__, PTR_ERR(karg));
+                return PTR_ERR(karg);
         }
 
         if (((iocnum = mpt_verify_adapter(karg->hdr.iocnum, &ioc)) < 0) ||