[PATCH] kmemleak: do not leak object after tree insertion error
In case when tree insertion fails due to already existing object
error, pointer to allocated object gets lost due to lookup_object()
overwrite. Free allocated object and return the existing one,
obtained from lookup_object().
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
---
mm/kmemleak.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 45eb621..4177d83 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -516,7 +516,7 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
int min_count, gfp_t gfp)
{
unsigned long flags;
- struct kmemleak_object *object;
+ struct kmemleak_object *object, *ex_object;
struct prio_tree_node *node;
object = kmem_cache_alloc(object_cache, gfp_kmemleak_mask(gfp));
@@ -578,17 +578,22 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
if (node != &object->tree_node) {
kmemleak_stop("Cannot insert 0x%lx into the object search tree "
"(already existing)\n", ptr);
- object = lookup_object(ptr, 1);
- spin_lock(&object->lock);
- dump_object_info(object);
- spin_unlock(&object->lock);
+ ex_object = lookup_object(ptr, 1);
+ spin_lock(&ex_object->lock);
+ dump_object_info(ex_object);
+ spin_unlock(&ex_object->lock);
- goto out;
+ goto out_error;
}
list_add_tail_rcu(&object->object_list, &object_list);
-out:
+
write_unlock_irqrestore(&kmemleak_lock, flags);
return object;
+out_error:
+ write_unlock_irqrestore(&kmemleak_lock, flags);
+ object->flags &= ~OBJECT_ALLOCATED;
+ put_object(object);
+ return ex_object;
}
/*
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