Author: Julia Lawall <julia@diku.dk> sizeof(codec->reg_cache) is just the size of the pointer. Elsewhere in the file, codec->reg_cache is used with sizeof(wm8900_reg_defaults), so the code is changed to do the same here. A simplified version of the semantic patch that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @@ expression *x; expression f; type T; @@ …