net/ipv4: Eliminate kstrdup memory leak

The string clone is only used as a temporary copy of the argument val
within the while loop, and so it should be freed before leaving the
function.  The call to strsep, however, modifies clone, so a pointer to the
front of the string is kept in saved_clone, to make it possible to free it.

The sematic match that finds this problem is as follows:

// <smpl>
@r exists@
local idexpression x;
expression E;
identifier l;
statement S;

*x= \(kasprintf\|kstrdup\)(...);
if (x == NULL) S
... when != kfree(x)
    when != E = x
if (...) {
  <... when != kfree(x)
* goto l;
* return ...;
// </smpl>

Signed-off-by: Julia Lawall <>
Signed-off-by: David S. Miller <>
1 file changed