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vmci: Fix a couple integer overflow tests

PATCH Applied Dan Carpenter 1 participant 1 message Mar 22, 2017

Subsystems (3)
Kernel janitors Char and misc drivers VMware VMCI driver
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Dan Carpenter

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#0 lore raw

PATCH 1/1 vmci: 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.

Signed-off-by Dan Carpenter <[email protected]>
drivers/misc/vmw_vmci/vmci_queue_pair.c +8 -2
index 498c0854305f..06c4974ee8dd 100644
@@ -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;