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Date: Mon, 10 Jun 2024 20:36:19 +0300
From: Fedor Pchelkin <pchelkin@ispras.ru>
To: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Aleksandr Mishin <amishin@t-argos.ru>, imx@lists.linux.dev, 
	lvc-project@linuxtesting.org, Shawn Guo <shawnguo@kernel.org>, 
	Bjorn Andersson <andersson@kernel.org>, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, 
	Oleksij Rempel <o.rempel@pengutronix.de>, Pengutronix Kernel Team <kernel@pengutronix.de>, 
	Fabio Estevam <festevam@gmail.com>, Sascha Hauer <s.hauer@pengutronix.de>, 
	linux-arm-kernel@lists.infradead.org, Peng Fan <peng.fan@nxp.com>
Subject: Re: [lvc-project] [PATCH] remoteproc: imx_rproc: Adjust phandle
 parsing issue while remapping optional addresses in imx_rproc_addr_init()
Message-ID: <20240610-4fb504648421659114538a50-pchelkin@ispras.ru>
References: <20240606075204.12354-1-amishin@t-argos.ru>
 <ZmcuFRfjKRQG9OXI@p14s>
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On Mon, 10. Jun 10:47, Mathieu Poirier wrote:
> On Thu, Jun 06, 2024 at 10:52:04AM +0300, Aleksandr Mishin wrote:
> > In imx_rproc_addr_init() "nph = of_count_phandle_with_args()" just counts
> > number of phandles. But phandles may be empty. So of_parse_phandle() in
> > the parsing loop (0 < a < nph) may return NULL which is later dereferenced.
> > Adjust this issue by adding NULL-return check.
> > 
> > Found by Linux Verification Center (linuxtesting.org) with SVACE.
> > 
> > Fixes: a0ff4aa6f010 ("remoteproc: imx_rproc: add a NXP/Freescale imx_rproc driver")
> > Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
> > ---
> >  drivers/remoteproc/imx_rproc.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
> > index 5a3fb902acc9..39eacd90af14 100644
> > --- a/drivers/remoteproc/imx_rproc.c
> > +++ b/drivers/remoteproc/imx_rproc.c
> > @@ -726,6 +726,8 @@ static int imx_rproc_addr_init(struct imx_rproc *priv,
> >  		struct resource res;
> >  
> >  		node = of_parse_phandle(np, "memory-region", a);
> > +		if (!node)
> 
> You're missing an "of_node_put()" before continuing.
> 

The node is NULL in this case so of_node_put() is not needed..?

Btw, there is a "rsc-table" node->name check in the the end of the loop
body. It was added recently with commit 5e4c1243071d ("remoteproc:
imx_rproc: support remote cores booted before Linux Kernel"). Seems to me
it forgot that of_node_put() is called way before that.

Also commit 61afafe8b938 ("remoteproc: imx_rproc: Fix refcount leak in
imx_rproc_addr_init") was dealing with the last of_node_put() call here
but it's still not in the right place I'd say.

> > +			continue;
> >  		/* Not map vdevbuffer, vdevring region */
> >  		if (!strncmp(node->name, "vdev", strlen("vdev"))) {
> >  			of_node_put(node);
> > -- 
> > 2.30.2
> > 
> >