[PATCH 1/3] mtip32xx: fix potential crash on SEC_ERASE_UNIT

[Selvan Mani]

The mtip driver lifted this code from elsewhere and then added a special
handling check for SEC_ERASE_UNIT. If the caller tries to do a security
erase but passes no output data for the command then outbuf is not
allocated and the driver duly explodes.

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
Signed-off-by: Selvan Mani <smani@xxxxxxxxxx>
Signed-off-by: Asai Thambi S P <asamymuthupa@xxxxxxxxxx>
---
 drivers/block/mtip32xx/mtip32xx.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index adc6f36..dfb7196 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -2218,8 +2218,8 @@ static int exec_drive_taskfile(struct driver_data *dd,
 		fis.device);
 
 	/* check for erase mode support during secure erase.*/
-	if ((fis.command == ATA_CMD_SEC_ERASE_UNIT)
-					&& (outbuf[0] & MTIP_SEC_ERASE_MODE)) {
+	if ((fis.command == ATA_CMD_SEC_ERASE_UNIT) && outbuf &&
+					(outbuf[0] & MTIP_SEC_ERASE_MODE)) {
 		erasemode = 1;
 	}
 
-- 
1.7.1
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