scsi: sg: fixup infoleak when using SG_GET_REQUEST_TABLE

When calling SG_GET_REQUEST_TABLE ioctl only a half-filled table is
returned; the remaining part will then contain stale kernel memory
information.  This patch zeroes out the entire table to avoid this
issue.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 1acdb6e..0419c22 100644 (file)
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -839,7 +839,6 @@ sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
        list_for_each_entry(srp, &sfp->rq_list, entry) {
                if (val > SG_MAX_QUEUE)
                        break;
-               memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
                rinfo[val].req_state = srp->done + 1;
                rinfo[val].problem =
                        srp->header.masked_status &
@@ -1047,8 +1046,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
                else {
                        sg_req_info_t *rinfo;
 
-                       rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
-                                                               GFP_KERNEL);
+                       rinfo = kzalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
+                                       GFP_KERNEL);
                        if (!rinfo)
                                return -ENOMEM;
                        read_lock_irqsave(&sfp->rq_list_lock, iflags);