From 50a7d3ba7c9ac5e0b7e03fc7f420180989361dbf Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Mon, 18 Jun 2018 10:50:33 -0700
Subject: [PATCH] dm writecache: use 2-factor allocator arguments
Git-commit: 50a7d3ba7c9ac5e0b7e03fc7f420180989361dbf
Patch-mainline: v4.18-rc3
References: bsc#1101116,fate#324698

This adjusts the allocator calls to use the 2-factor argument style, as
already done treewide for better defense against allocator overflows.

Signed-off-by: Kees Cook <keescook@chromium.org>
[snitzer: tweaked code to leave assignment in a test alone]
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
 drivers/md/dm-writecache.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -15,6 +15,7 @@
 #include <linux/dax.h>
 #include <linux/pfn_t.h>
 #include <linux/libnvdimm.h>
+#include <linux/overflow.h>
 
 #define DM_MSG_PREFIX "writecache"
 
@@ -259,7 +260,7 @@ static int persistent_memory_claim(struc
 	if (da != p) {
 		long i;
 		wc->memory_map = NULL;
-		pages = kvmalloc(p * sizeof(struct page *), GFP_KERNEL);
+		pages = kvmalloc_array(p, sizeof(struct page *), GFP_KERNEL);
 		if (!pages) {
 			r = -ENOMEM;
 			goto err2;
@@ -860,7 +861,7 @@ static int writecache_alloc_entries(stru
 
 	if (wc->entries)
 		return 0;
-	wc->entries = vmalloc(sizeof(struct wc_entry) * wc->n_blocks);
+	wc->entries = vmalloc(array_size(sizeof(struct wc_entry), wc->n_blocks));
 	if (!wc->entries)
 		return -ENOMEM;
 	for (b = 0; b < wc->n_blocks; b++) {
@@ -1481,9 +1482,9 @@ static void __writecache_writeback_pmem(
 		wb->bio.bi_iter.bi_sector = read_original_sector(wc, e);
 		wb->page_offset = PAGE_SIZE;
 		if (max_pages <= WB_LIST_INLINE ||
-		    unlikely(!(wb->wc_list = kmalloc(max_pages * sizeof(struct wc_entry *),
-						     GFP_NOIO | __GFP_NORETRY |
-						     __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
+		    unlikely(!(wb->wc_list = kmalloc_array(max_pages, sizeof(struct wc_entry *),
+							   GFP_NOIO | __GFP_NORETRY |
+							   __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
 			wb->wc_list = wb->wc_list_inline;
 			max_pages = WB_LIST_INLINE;
 		}