[PATCH] megaraid: fix possible uninitialized-variable access in megadev_ioctl()

[Tuo Li <islituo@gmail.com>]

The variable pthru_dma_hndl is not initialized at the beginning of the
function megadev_ioctl(). It remains uninitialized if the variable
uioc.xferlen is zero at line 3275. However, it is accessed at line 3311:
  mc.xferaddr = (u32)data_dma_hndl;

To fix this possible bug, pthru_dma_hndl is initialized to zero at the
beginning of the function megadev_ioctl().

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
---
 drivers/scsi/megaraid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
index 56910e94dbf2..8b0676b862fb 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -2975,7 +2975,7 @@ megadev_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 	mega_passthru	*pthru;		/* copy user passthru here */
 	dma_addr_t	pthru_dma_hndl;
 	void		*data = NULL;	/* data to be transferred */
-	dma_addr_t	data_dma_hndl;	/* dma handle for data xfer area */
+	dma_addr_t	data_dma_hndl = 0;	/* dma handle for data xfer area */
 	megacmd_t	mc;
 #if MEGA_HAVE_STATS
 	megastat_t	__user *ustats = NULL;
-- 
2.25.1