[PATCH] SCSI: sd: fix null dereference

[PATCH] SCSI: sd: fix null dereference

[Sudip Mukherjee]

we were dereferencing sdkp first and then we were checking for it
being NULL. 

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---
 drivers/scsi/sd_dif.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/sd_dif.c b/drivers/scsi/sd_dif.c
index 14c7d42..a514645 100644
--- a/drivers/scsi/sd_dif.c
+++ b/drivers/scsi/sd_dif.c
@@ -40,11 +40,16 @@
  */
 void sd_dif_config_host(struct scsi_disk *sdkp)
 {
-	struct scsi_device *sdp = sdkp->device;
-	struct gendisk *disk = sdkp->disk;
-	u8 type = sdkp->protection_type;
+	struct scsi_device *sdp = NULL;
+	struct gendisk *disk = NULL;
+	u8 type;
 	int dif, dix;
 
+	if (!sdkp)
+		return;
+	sdp = sdkp->device;
+	disk = sdkp->disk;
+	type = sdkp->protection_type;
 	dif = scsi_host_dif_capable(sdp->host, type);
 	dix = scsi_host_dix_capable(sdp->host, type);
 
@@ -77,9 +82,6 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
 
 		disk->integrity->flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
 
-		if (!sdkp)
-			return;
-
 		if (type == SD_DIF_TYPE3_PROTECTION)
 			disk->integrity->tag_size = sizeof(u16) + sizeof(u32);
 		else
-- 
1.8.1.2

Re: [PATCH] SCSI: sd: fix null dereference

[Martin K. Petersen]

>>>>> "Sudip" == Sudip Mukherjee <sudipm.mukherjee@gmail.com> writes:

Sudip> we were dereferencing sdkp first and then we were checking for it
Sudip> being NULL.

http://marc.info/?l=linux-kernel&m=142564395705827&w=2

-- 
Martin K. Petersen	Oracle Linux Engineering