[SRU][Trusty][PATCH 1/1] scsi: sg: fixup infoleak when using SG_GET_REQUEST_TABLE

[Kleber Sacilotto de Souza]

From: Hannes Reinecke <hare at suse.de>

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

CVE-2017-14991
(backported from commit 3e0097499839e0fe3af380410eababe5a47c4cf9)
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>
---
 drivers/scsi/sg.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 47b8f7b8b7b4..1c3dd355b317 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1003,14 +1003,13 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 			sg_req_info_t *rinfo;
 			unsigned int ms;
 
-			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);
 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 			     ++val, srp = srp ? srp->nextrp : srp) {
-				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 				if (srp) {
 					rinfo[val].req_state = srp->done + 1;
 					rinfo[val].problem =
-- 
2.17.1