[PATCH AUTOSEL for 4.4 015/167] drivers/misc/vmw_vmci/vmci_queue_pair.c: fix a couple integer overflow tests

Sasha Levin
2018-03-19T16:05:39Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 146180c052a00172f4dc08eaade836fd02f61fb5 ]

The "DIV_ROUND_UP(size, PAGE_SIZE)" operation can overflow if "size" is
more than ULLONG_MAX - PAGE_SIZE.

Link: http://lkml.kernel.org/r/20170322111950.GA11279@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/misc/vmw_vmci/vmci_queue_pair.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index f42d9c4e4561..cc277f7849b0 100644
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -298,8 +298,11 @@ static void *qp_alloc_queue(u64 size, u32 flags)
size_t pas_size;
size_t vas_size;
size_t queue_size = sizeof(*queue) + sizeof(*queue->kernel_if);
- const u64 num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
+ u64 num_pages;

+ if (size > SIZE_MAX - PAGE_SIZE)
+ return NULL;
+ num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
if (num_pages >
(SIZE_MAX - queue_size) /
(sizeof(*queue->kernel_if->u.g.pas) +
@@ -624,9 +627,12 @@ static struct vmci_queue *qp_host_alloc_queue(u64 size)
{
struct vmci_queue *queue;
size_t queue_page_size;
- const u64 num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
+ u64 num_pages;
const size_t queue_size = sizeof(*queue) + sizeof(*(queue->kernel_if));

+ if (size > SIZE_MAX - PAGE_SIZE)
+ return NULL;
+ num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
if (num_pages > (SIZE_MAX - queue_size) /
sizeof(*queue->kernel_if->u.h.page))
return NULL;
--
2.14.1