If list_for_each_entry, etc complete a traversal of the list, the iterator
variable ends up pointing to an address at an offset from the list head,
and not a meaningful structure. Thus this value should not be used after
the end of the iterator. Replace a field access from orphan by NULL in two
places.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier c;
expression E;
iterator name list_for_each_entry;
statement S;
@@
list_for_each_entry(c,...) { ... when != break;
when forall
when strict
}
...
(
c = E
|
*c
)
// </smpl>
Artem: fortunately, this did not cause any issues because we iterate the orphan
list using the elements count, so we never dereferenced the corrupted pointer.
This is why I do not send this patch to -stable. But otherwise - well spotted!
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
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