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[24.6.192.50]) by smtp.gmail.com with ESMTPSA id r8sm14216610pgr.48.2018.12.16.23.56.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sun, 16 Dec 2018 23:56:52 -0800 (PST) From: frowand.list@gmail.com To: robh+dt@kernel.org, Michael Bringmann , linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman , Tyrel Datwyler , Thomas Falcon , Juliet Kim , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 0/2] of: phandle_cache, fix refcounts, remove stale entry Date: Sun, 16 Dec 2018 23:56:34 -0800 Message-Id: <1545033396-24485-1-git-send-email-frowand.list@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Frank Rowand Non-overlay dynamic devicetree node removal may leave the node in the phandle cache. Subsequent calls to of_find_node_by_phandle() will incorrectly find the stale entry. This bug exposed the foloowing phandle cache refcount bug. The refcount of phandle_cache entries is not incremented while in the cache, allowing use after free error after kfree() of the cached entry. Changes since v1: - make __of_free_phandle_cache() static - add WARN_ON(1) for unexpected condition in of_find_node_by_phandle() Frank Rowand (2): of: of_node_get()/of_node_put() nodes held in phandle cache of: __of_detach_node() - remove node from phandle cache drivers/of/base.c | 100 ++++++++++++++++++++++++++++++++++++------------ drivers/of/dynamic.c | 3 ++ drivers/of/of_private.h | 4 ++ 3 files changed, 82 insertions(+), 25 deletions(-) -- Frank Rowand