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",