[PATCH] clk: mmp: pxa168: Fix memory leak in pxa168_clk_init()

[PATCH] clk: mmp: pxa168: Fix memory leak in pxa168_clk_init()

[Kuan-Wei Chiu]

In cases where mapping of mpmu/apmu/apbc registers fails, the code path
does not handle the failure gracefully, potentially leading to a memory
leak. This fix ensures proper cleanup by freeing the allocated memory
for 'pxa_unit' before returning.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
---
 drivers/clk/mmp/clk-of-pxa168.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/clk/mmp/clk-of-pxa168.c b/drivers/clk/mmp/clk-of-pxa168.c
index fb0df64cf053..c5a7ba1deaa3 100644
--- a/drivers/clk/mmp/clk-of-pxa168.c
+++ b/drivers/clk/mmp/clk-of-pxa168.c
@@ -308,18 +308,21 @@ static void __init pxa168_clk_init(struct device_node *np)
 	pxa_unit->mpmu_base = of_iomap(np, 0);
 	if (!pxa_unit->mpmu_base) {
 		pr_err("failed to map mpmu registers\n");
+		kfree(pxa_unit);
 		return;
 	}
 
 	pxa_unit->apmu_base = of_iomap(np, 1);
 	if (!pxa_unit->apmu_base) {
 		pr_err("failed to map apmu registers\n");
+		kfree(pxa_unit);
 		return;
 	}
 
 	pxa_unit->apbc_base = of_iomap(np, 2);
 	if (!pxa_unit->apbc_base) {
 		pr_err("failed to map apbc registers\n");
+		kfree(pxa_unit);
 		return;
 	}
 
-- 
2.25.1

Re: [PATCH] clk: mmp: pxa168: Fix memory leak in pxa168_clk_init()

[Conor Dooley]

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On Mon, Dec 11, 2023 at 01:52:32AM +0800, Kuan-Wei Chiu wrote:
> In cases where mapping of mpmu/apmu/apbc registers fails, the code path
> does not handle the failure gracefully, potentially leading to a memory
> leak. This fix ensures proper cleanup by freeing the allocated memory
> for 'pxa_unit' before returning.
> 
> Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>

I dunno why you have CCed me on this tbh, I guess I must have acked a
patch related to this driver's bindings somehow.

I wonder, is there actually any point in freeing these, isn't the system
going to fail to actually boot if these allocations fail?

> ---
>  drivers/clk/mmp/clk-of-pxa168.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/clk/mmp/clk-of-pxa168.c b/drivers/clk/mmp/clk-of-pxa168.c
> index fb0df64cf053..c5a7ba1deaa3 100644
> --- a/drivers/clk/mmp/clk-of-pxa168.c
> +++ b/drivers/clk/mmp/clk-of-pxa168.c
> @@ -308,18 +308,21 @@ static void __init pxa168_clk_init(struct device_node *np)
>  	pxa_unit->mpmu_base = of_iomap(np, 0);
>  	if (!pxa_unit->mpmu_base) {
>  		pr_err("failed to map mpmu registers\n");
> +		kfree(pxa_unit);
>  		return;
>  	}
>  
>  	pxa_unit->apmu_base = of_iomap(np, 1);
>  	if (!pxa_unit->apmu_base) {
>  		pr_err("failed to map apmu registers\n");
> +		kfree(pxa_unit);
>  		return;
>  	}
>  
>  	pxa_unit->apbc_base = of_iomap(np, 2);
>  	if (!pxa_unit->apbc_base) {
>  		pr_err("failed to map apbc registers\n");
> +		kfree(pxa_unit);
>  		return;
>  	}
>  
> -- 
> 2.25.1
> 

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Re: [PATCH] clk: mmp: pxa168: Fix memory leak in pxa168_clk_init()

[Kuan-Wei Chiu]

On Mon, Dec 11, 2023 at 01:19:17PM +0000, Conor Dooley wrote:
> On Mon, Dec 11, 2023 at 01:52:32AM +0800, Kuan-Wei Chiu wrote:
> > In cases where mapping of mpmu/apmu/apbc registers fails, the code path
> > does not handle the failure gracefully, potentially leading to a memory
> > leak. This fix ensures proper cleanup by freeing the allocated memory
> > for 'pxa_unit' before returning.
> > 
> > Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
> 
> I dunno why you have CCed me on this tbh, I guess I must have acked a
> patch related to this driver's bindings somehow.
>
I included you in the CC list based on the results from
./scripts/get_maintainer.pl, which listed your email. I apologize for
any inconvenience. I will be more careful in selecting the recipients
for my patches in the future.

> I wonder, is there actually any point in freeing these, isn't the system
> going to fail to actually boot if these allocations fail?
> 
I'm not familiar with the boot process. I noticed similar cleanup in
related code (e.g., clk-of-pxa1928.c) and thought it might be an
oversight in pxa168. If releasing memory here isn't essential, I'm
inclined to drop the patch.

However, if the cleanup is necessary, I believe additional iounmap,
similar to commit 19b9f29 (clk:mmp:clk-of-pxa910: Free memory and
Unmap region obtained by kzmalloc and of_iomap), may be required.
If necessary, I'm willing to send a v2 patch with the additional
changes.

Best regards,
Kuan-Wei Chiu
> > ---
> >  drivers/clk/mmp/clk-of-pxa168.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/clk/mmp/clk-of-pxa168.c b/drivers/clk/mmp/clk-of-pxa168.c
> > index fb0df64cf053..c5a7ba1deaa3 100644
> > --- a/drivers/clk/mmp/clk-of-pxa168.c
> > +++ b/drivers/clk/mmp/clk-of-pxa168.c
> > @@ -308,18 +308,21 @@ static void __init pxa168_clk_init(struct device_node *np)
> >  	pxa_unit->mpmu_base = of_iomap(np, 0);
> >  	if (!pxa_unit->mpmu_base) {
> >  		pr_err("failed to map mpmu registers\n");
> > +		kfree(pxa_unit);
> >  		return;
> >  	}
> >  
> >  	pxa_unit->apmu_base = of_iomap(np, 1);
> >  	if (!pxa_unit->apmu_base) {
> >  		pr_err("failed to map apmu registers\n");
> > +		kfree(pxa_unit);
> >  		return;
> >  	}
> >  
> >  	pxa_unit->apbc_base = of_iomap(np, 2);
> >  	if (!pxa_unit->apbc_base) {
> >  		pr_err("failed to map apbc registers\n");
> > +		kfree(pxa_unit);
> >  		return;
> >  	}
> >  
> > -- 
> > 2.25.1
> > 

Re: [PATCH] clk: mmp: pxa168: Fix memory leak in pxa168_clk_init()

[Stephen Boyd]

Quoting Kuan-Wei Chiu (2023-12-10 09:52:32)
> In cases where mapping of mpmu/apmu/apbc registers fails, the code path
> does not handle the failure gracefully, potentially leading to a memory
> leak. This fix ensures proper cleanup by freeing the allocated memory
> for 'pxa_unit' before returning.
> 
> Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
> ---

Applied to clk-next