fs-verity: Use struct_size() helper in enable_verity()

Follow the best practice for allocating a variable-sized structure.

Signed-off-by: Zhang Jianhua <chris.zjh@huawei.com>
[ebiggers: adjusted commit message]
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20220519022450.2434483-1-chris.zjh@huawei.com

diff --git a/fs/verity/enable.c b/fs/verity/enable.c
index 0f953bae17476b03e0fc20bc072749dc8c9612c3..d52872c808fffed4024397bbf3511c35d0f6c9da 100644 (file)
--- a/fs/verity/enable.c
+++ b/fs/verity/enable.c
@@ -202,7 +202,7 @@ static int enable_verity(struct file *filp,
        const struct fsverity_operations *vops = inode->i_sb->s_vop;
        struct merkle_tree_params params = { };
        struct fsverity_descriptor *desc;
-       size_t desc_size = sizeof(*desc) + arg->sig_size;
+       size_t desc_size = struct_size(desc, signature, arg->sig_size);
        struct fsverity_info *vi;
        int err;