diff --git a/block/bsg.c b/block/bsg.c
index 8a05a40..a57046d 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -655,6 +655,9 @@
 
 	dprintk("%s: write %Zd bytes\n", bd->name, count);
 
+	if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
+		return -EINVAL;
+
 	bsg_set_block(bd, file);
 
 	bytes_written = 0;
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 070332e..dbe5b4b 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -581,6 +581,9 @@
 	sg_io_hdr_t *hp;
 	unsigned char cmnd[SG_MAX_CDB_SIZE];
 
+	if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
+		return -EINVAL;
+
 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 		return -ENXIO;
 	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,