[PATCH 12/26] btrfs: zoned: use array_size

[Julia Lawall]

Use array_size to protect against multiplication overflows.

The changes were done using the following Coccinelle semantic patch:

// <smpl>
@@
    size_t e1,e2;
    expression COUNT;
    identifier alloc = {vmalloc,vzalloc,kvmalloc,kvzalloc};
@@

(
      alloc(
-           (e1) * (e2)
+           array_size(e1, e2)
      ,...)
|
      alloc(
-           (e1) * (COUNT)
+           array_size(COUNT, e1)
      ,...)
)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxxx>

---
 fs/btrfs/zoned.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 39828af4a4e8..0550ce98dcae 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -464,8 +464,9 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache)
 	 * use the cache.
 	 */
 	if (populate_cache && bdev_is_zoned(device->bdev)) {
-		zone_info->zone_cache = vzalloc(sizeof(struct blk_zone) *
-						zone_info->nr_zones);
+		zone_info->zone_cache =
+			vzalloc(array_size(zone_info->nr_zones,
+					   sizeof(struct blk_zone)));
 		if (!zone_info->zone_cache) {
 			btrfs_err_in_rcu(device->fs_info,
 				"zoned: failed to allocate zone cache for %s",