scsi: hpsa: Replace kmalloc() + copy_from_user() with memdup_user()

Replace kmalloc() followed by copy_from_user() with memdup_user() to
improve and simplify hpsa_passthru_ioctl().

Since memdup_user() already allocates memory, use kzalloc() in the else
branch instead of manually zeroing 'buff' using memset(0).

Return early if an error occurs and remove the 'out_kfree' label.

No functional changes intended.

Signed-off-by: Thorsten Blum <[email protected]>
Acked-by: Don Brace <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: toblux

drivers/scsi/hpsa.c

@@ -6402,18 +6402,14 @@ static int hpsa_passthru_ioctl(struct ctlr_info *h,
 		return -EINVAL;
 	}
 	if (iocommand->buf_size > 0) {
-		buff = kmalloc(iocommand->buf_size, GFP_KERNEL);
-		if (buff == NULL)
-			return -ENOMEM;
 		if (iocommand->Request.Type.Direction & XFER_WRITE) {
-			/* Copy the data into the buffer we created */
-			if (copy_from_user(buff, iocommand->buf,
-				iocommand->buf_size)) {
-				rc = -EFAULT;
-				goto out_kfree;
-			}
+			buff = memdup_user(iocommand->buf, iocommand->buf_size);
+			if (IS_ERR(buff))
+				return PTR_ERR(buff);
 		} else {
-			memset(buff, 0, iocommand->buf_size);
+			buff = kzalloc(iocommand->buf_size, GFP_KERNEL);
+			if (!buff)
+				return -ENOMEM;
 		}
 	}
 	c = cmd_alloc(h);
@@ -6473,7 +6469,6 @@ static int hpsa_passthru_ioctl(struct ctlr_info *h,
 	}
 out:
 	cmd_free(h, c);
-out_kfree:
 	kfree(buff);
 	return rc;
 }