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[24.6.192.50]) by smtp.gmail.com with ESMTPSA id c20sm4965074pfc.92.2018.12.13.22.46.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 13 Dec 2018 22:46:34 -0800 (PST) Subject: Re: [PATCH 0/2] of: phandle_cache, fix refcounts, remove stale entry From: Frank Rowand 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 References: <1544769771-5468-1-git-send-email-frowand.list@gmail.com> Message-ID: <84933c5e-04b1-df82-daec-cbae1017a830@gmail.com> Date: Thu, 13 Dec 2018 22:46:32 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <1544769771-5468-1-git-send-email-frowand.list@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Michael Bringmann, On 12/13/18 10:42 PM, frowand.list@gmail.com wrote: > 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. > > 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 | 99 ++++++++++++++++++++++++++++++++++++------------- > drivers/of/dynamic.c | 3 ++ > drivers/of/of_private.h | 4 ++ > 3 files changed, 81 insertions(+), 25 deletions(-) > Can you please test that these patches fix the problem that you reported in: [PATCH v03] powerpc/mobility: Fix node detach/rename problem Thanks, Frank