Author: Julia Lawall <julia@diku.dk> drvdata needds to be freed before leaving the function in an error case. A simplified version of the semantic match that finds the problem is as follows: (http://coccinelle.lip6.fr) // @r exists@ local idexpression x; statement S; identifier f1; position p1,p2; expression *ptr != NULL; @@ x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(…); … if (x …