From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: Re: [PATCH] reset: Fix potential use-after-free in __of_reset_control_get() Date: Mon, 08 Oct 2018 15:28:49 +0200 Message-ID: <1539005329.11512.26.camel@pengutronix.de> References: <20181008111435.25994-1-geert+renesas@glider.be> <1539003375.11512.19.camel@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Geert Uytterhoeven Cc: Geert Uytterhoeven , Linux Kernel Mailing List , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" List-Id: devicetree@vger.kernel.org On Mon, 2018-10-08 at 15:12 +0200, Geert Uytterhoeven wrote: > Hi Philipp, > > On Mon, Oct 8, 2018 at 2:56 PM Philipp Zabel wrote: > > On Mon, 2018-10-08 at 13:14 +0200, Geert Uytterhoeven wrote: > > > Calling of_node_put() decreases the reference count of a device tree > > > object, and may free some data. > > > > > > However, the of_phandle_args structure embedding it is passed to > > > reset_controller_dev.of_xlate() after that, so it may still be accessed. > > > > > > Move the call to of_node_put() down to fix this. > > > > > > Signed-off-by: Geert Uytterhoeven > > > --- > > > drivers/reset/core.c | 15 ++++++++------- > > > 1 file changed, 8 insertions(+), 7 deletions(-) > > > > > > diff --git a/drivers/reset/core.c b/drivers/reset/core.c > > > index 225e34c56b94a2e3..bc9df10d31b4bae1 100644 > > > --- a/drivers/reset/core.c > > > +++ b/drivers/reset/core.c > > > @@ -496,27 +496,28 @@ struct reset_control *__of_reset_control_get(struct device_node *node, [...] > > > /* reset_list_mutex also protects the rcdev's reset_control list */ > > > rstc = __reset_control_get_internal(rcdev, rstc_id, shared); > > > > > > +out: > > > + of_node_put(args.np); > > > mutex_unlock(&reset_list_mutex); > > > > Thank you for the patch. I'd like to move of_node_put after mutex_unlock > > for symmetry. If you agree, I can switch the two when applying. > > No objection, thanks! Applied to reset/next with that change. regards Philipp