drivers/misc/vmw_vmci/vmci_queue_pair.c: fix a couple integer overflow tests

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>

diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index 498c0854305f5a5ac0fa6f5d2b481c479e5714ff..06c4974ee8dd1ee40b328d2bc84ff751480a34c1 100644 (file)
--- 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;