[PATCH 5.17 050/158] selinux: fix bad cleanup on error in hashtab_duplicate()

Greg Kroah-Hartman
2022-05-23T17:53:52Z

From: Ondrej Mosnacek <omosnace@redhat.com>

commit 6254bd3db316c9ccb3b05caa8b438be63245466f upstream.

The code attempts to free the 'new' pointer using kmem_cache_free(),
which is wrong because this function isn't responsible of freeing it.
Instead, the function should free new->htable and clear the contents of
*new (to prevent double-free).

Cc: stable@vger.kernel.org
Fixes: c7c556f1e81b ("selinux: refactor changing booleans")
Reported-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
security/selinux/ss/hashtab.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/security/selinux/ss/hashtab.c
+++ b/security/selinux/ss/hashtab.c
@@ -179,7 +179,8 @@ int hashtab_duplicate(struct hashtab *ne
kmem_cache_free(hashtab_node_cachep, cur);
}
}
- kmem_cache_free(hashtab_node_cachep, new);
+ kfree(new->htable);
+ memset(new, 0, sizeof(*new));
return -ENOMEM;
}