dm crypt: use struct_size() when allocating encryption context

Use struct_size() to avoid open-coded equivalent that is prone to a type
mistake.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 1b16d34bb78518a1849aa331c6da2ac1da0e8586..2587e94b05114757df520bc1b630f2fa78a1c085 100644 (file)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -2699,7 +2699,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                return -EINVAL;
        }
 
-       cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
+       cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL);
        if (!cc) {
                ti->error = "Cannot allocate encryption context";
                return -ENOMEM;