[PATCH 4.13 066/109] scsi: sg: fixup infoleak when using SG_GET_REQUEST_TABLE

Greg Kroah-Hartman
2017-09-24T20:43:01Z

From: Hannes Reinecke <hare@suse.de>

commit 3e0097499839e0fe3af380410eababe5a47c4cf9 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/sg.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -839,7 +839,6 @@ sg_fill_request_table(Sg_fd *sfp, sg_req
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
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);