[PATCH] Staging: bcm: Fix potential buffer overflow and style cleanups

[Javier Martinez Canillas]

bcm driver copies from userpace with the following statement:

copy_from_user(&RxCntrlMsgBitMask, IoBuffer.InputBuffer, IoBuffer.InputLength);

Compiling gives the following warning:

In function ‘copy_from_user’,
    inlined from ‘bcm_char_ioctl’ at drivers/staging/bcm/Bcmchar.c:2030:
linux-next/arch/x86/include/asm/uaccess_32.h:212: warning: call to
‘copy_from_user_overflow’ declared with attribute warning: copy_from_user()
buffer size is not provably correct.

RxCntrlMsgBitMask is of type unsigned long so it is wrong
to copy InputLenght bytes. Only we have to copy sizeof(unsigned long) bytes.

This patch solves the issue and also make some style cleanups.

Signed-off-by: Javier Martinez Canillas <martinez.javier at gmail.com>
---
 drivers/staging/bcm/Bcmchar.c |   44 ++++++++++++++++++++++------------------
 1 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/drivers/staging/bcm/Bcmchar.c b/drivers/staging/bcm/Bcmchar.c
index 31674ea..c78afe8 100644
--- a/drivers/staging/bcm/Bcmchar.c
+++ b/drivers/staging/bcm/Bcmchar.c
@@ -2015,28 +2015,32 @@ static long bcm_char_ioctl(struct file *filp, UINT cmd, ULONG arg)
 				break ;
 			 }
 
-		case IOCTL_BCM_CNTRLMSG_MASK:
-			 {
-				ULONG RxCntrlMsgBitMask = 0 ;
+	case IOCTL_BCM_CNTRLMSG_MASK:
+	{
+	ULONG RxCntrlMsgBitMask = 0;
 
-				/* Copy Ioctl Buffer structure */
-				Status = copy_from_user(&IoBuffer, argp, sizeof(IOCTL_BUFFER));
-				if(Status)
-				{
-					BCM_DEBUG_PRINT(Adapter,DBG_TYPE_OTHERS, OSAL_DBG, DBG_LVL_ALL,"copy of Ioctl buffer is failed from user space");
-					break;
-				}
+        /* Copy Ioctl Buffer structure */
+	Status = copy_from_user(&IoBuffer, argp, sizeof(IOCTL_BUFFER));
+	if (Status) {
+		BCM_DEBUG_PRINT(Adapter, DBG_TYPE_OTHERS, OSAL_DBG, DBG_LVL_ALL,
+				"copy of Ioctl buffer is failed from user space");
+		break;
+	}
 
-				Status = copy_from_user(&RxCntrlMsgBitMask, IoBuffer.InputBuffer, IoBuffer.InputLength);
-				if(Status)
-				{
-					BCM_DEBUG_PRINT(Adapter,DBG_TYPE_OTHERS, OSAL_DBG, DBG_LVL_ALL,"copy of control bit mask failed from user space");
-					break;
-				}
-				BCM_DEBUG_PRINT(Adapter,DBG_TYPE_OTHERS, OSAL_DBG, DBG_LVL_ALL,"\n Got user defined cntrl msg bit mask :%lx", RxCntrlMsgBitMask);
-				pTarang->RxCntrlMsgBitMask = RxCntrlMsgBitMask ;
-			 }
-			 break;
+	Status = copy_from_user(&RxCntrlMsgBitMask, IoBuffer.InputBuffer,
+				sizeof(ULONG));
+	if (Status) {
+		BCM_DEBUG_PRINT(Adapter, DBG_TYPE_OTHERS, OSAL_DBG, DBG_LVL_ALL,
+				"copy of control bit mask failed from user space");
+		break;
+	}
+
+	BCM_DEBUG_PRINT(Adapter, DBG_TYPE_OTHERS, OSAL_DBG, DBG_LVL_ALL,
+			"\n Got user defined cntrl msg bit mask :%lx", RxCntrlMsgBitMask);
+
+	pTarang->RxCntrlMsgBitMask = RxCntrlMsgBitMask ;
+	}
+	break;
 			case IOCTL_BCM_GET_DEVICE_DRIVER_INFO:
 			{
 				DEVICE_DRIVER_INFO DevInfo;
-- 
1.7.0.4