[PATCH 4.9 10/30] mips/pic32/pic32mzda: Fix refcount leak bugs

Greg Kroah-Hartman posted 30 patches 3 years, 6 months ago
[PATCH 4.9 10/30] mips/pic32/pic32mzda: Fix refcount leak bugs
Posted by Greg Kroah-Hartman 3 years, 6 months ago
From: Liang He <windhl@126.com>

[ Upstream commit eb9e9bc4fa5fb489c92ec588b3fb35f042ba6d86 ]

of_find_matching_node(), of_find_compatible_node() and
of_find_node_by_path() will return node pointers with refcout
incremented. We should call of_node_put() when they are not
used anymore.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/pic32/pic32mzda/init.c | 7 ++++++-
 arch/mips/pic32/pic32mzda/time.c | 3 +++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/mips/pic32/pic32mzda/init.c b/arch/mips/pic32/pic32mzda/init.c
index 406c6c5cec29..f8985d4573e6 100644
--- a/arch/mips/pic32/pic32mzda/init.c
+++ b/arch/mips/pic32/pic32mzda/init.c
@@ -131,13 +131,18 @@ static int __init pic32_of_prepare_platform_data(struct of_dev_auxdata *lookup)
 		np = of_find_compatible_node(NULL, NULL, lookup->compatible);
 		if (np) {
 			lookup->name = (char *)np->name;
-			if (lookup->phys_addr)
+			if (lookup->phys_addr) {
+				of_node_put(np);
 				continue;
+			}
 			if (!of_address_to_resource(np, 0, &res))
 				lookup->phys_addr = res.start;
+			of_node_put(np);
 		}
 	}
 
+	of_node_put(root);
+
 	return 0;
 }
 
diff --git a/arch/mips/pic32/pic32mzda/time.c b/arch/mips/pic32/pic32mzda/time.c
index 62a0a78b6c64..bfafe241c1b5 100644
--- a/arch/mips/pic32/pic32mzda/time.c
+++ b/arch/mips/pic32/pic32mzda/time.c
@@ -40,6 +40,9 @@ static unsigned int pic32_xlate_core_timer_irq(void)
 		goto default_map;
 
 	irq = irq_of_parse_and_map(node, 0);
+
+	of_node_put(node);
+
 	if (!irq)
 		goto default_map;
 
-- 
2.35.1
Re: [PATCH 4.9 10/30] mips/pic32/pic32mzda: Fix refcount leak bugs
Posted by Pavel Machek 3 years, 6 months ago
Hi!

> [ Upstream commit eb9e9bc4fa5fb489c92ec588b3fb35f042ba6d86 ]
> 
> of_find_matching_node(), of_find_compatible_node() and
> of_find_node_by_path() will return node pointers with refcout
> incremented. We should call of_node_put() when they are not
> used anymore.

True. But we absolutely should not call put when we still use the
reference.

> +++ b/arch/mips/pic32/pic32mzda/init.c
> @@ -131,13 +131,18 @@ static int __init pic32_of_prepare_platform_data(struct of_dev_auxdata *lookup)
>  		np = of_find_compatible_node(NULL, NULL, lookup->compatible);
>  		if (np) {
>  			lookup->name = (char *)np->name;
> -			if (lookup->phys_addr)
> +			if (lookup->phys_addr) {
> +				of_node_put(np);
>  				continue;
> +			}
>  			if (!of_address_to_resource(np, 0, &res))
>  				lookup->phys_addr = res.start;
> +			of_node_put(np);
>  		}
>  	}

As we stored np->name in lookup, we should not be putting that node,
we are still using it.

Best regards,
								Pavel
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Re: [PATCH 4.9 10/30] mips/pic32/pic32mzda: Fix refcount leak bugs
Posted by Greg Kroah-Hartman 3 years, 6 months ago
On Mon, Sep 26, 2022 at 12:40:42PM +0200, Pavel Machek wrote:
> Hi!
> 
> > [ Upstream commit eb9e9bc4fa5fb489c92ec588b3fb35f042ba6d86 ]
> > 
> > of_find_matching_node(), of_find_compatible_node() and
> > of_find_node_by_path() will return node pointers with refcout
> > incremented. We should call of_node_put() when they are not
> > used anymore.
> 
> True. But we absolutely should not call put when we still use the
> reference.
> 
> > +++ b/arch/mips/pic32/pic32mzda/init.c
> > @@ -131,13 +131,18 @@ static int __init pic32_of_prepare_platform_data(struct of_dev_auxdata *lookup)
> >  		np = of_find_compatible_node(NULL, NULL, lookup->compatible);
> >  		if (np) {
> >  			lookup->name = (char *)np->name;
> > -			if (lookup->phys_addr)
> > +			if (lookup->phys_addr) {
> > +				of_node_put(np);
> >  				continue;
> > +			}
> >  			if (!of_address_to_resource(np, 0, &res))
> >  				lookup->phys_addr = res.start;
> > +			of_node_put(np);
> >  		}
> >  	}
> 
> As we stored np->name in lookup, we should not be putting that node,
> we are still using it.

Now dropped, thanks.

greg k-h