2023-04-24 13:04:09

by XuDong Liu

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Subject: [Patch] serial: 8250_bcm7271: fix leak in `brcmuart_probe`

Smatch reports:
drivers/tty/serial/8250/8250_bcm7271.c:1120 brcmuart_probe() warn:
'baud_mux_clk' from clk_prepare_enable() not released on lines: 1032.

In the function brcmuart_probe(), baud_mux_clk was not correctly released
in subsequent error handling, which may cause memory leaks.

To fix this issue, an error handling branch, err_clk_put, is added to
release the variable using clk_put(), and an err_disable branch is added
to meet the requirement of balancing clk_disable and clk_enable calls.

Fixes: 15ac1122fd6d ("serial: 8250_bcm7271: Fix arbitration handling")
Signed-off-by: XuDong Liu <[email protected]>
Reviewed-by: Dongliang Mu <[email protected]>
---
The issue is discovered by static analysis, and the patch is not tested
yet.
---
drivers/tty/serial/8250/8250_bcm7271.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
index f801b1f5b46c..b1670558868b 100644
--- a/drivers/tty/serial/8250/8250_bcm7271.c
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -1023,7 +1023,7 @@ static int brcmuart_probe(struct platform_device *pdev)
dev_dbg(dev, "BAUD MUX clock found\n");
ret = clk_prepare_enable(baud_mux_clk);
if (ret)
- goto release_dma;
+ goto err_clk_put;
priv->baud_mux_clk = baud_mux_clk;
init_real_clk_rates(dev, priv);
clk_rate = priv->default_mux_rate;
@@ -1032,7 +1032,7 @@ static int brcmuart_probe(struct platform_device *pdev)
if (clk_rate == 0) {
dev_err(dev, "clock-frequency or clk not defined\n");
ret = -EINVAL;
- goto release_dma;
+ goto err_clk_disable;
}

dev_dbg(dev, "DMA is %senabled\n", priv->dma_enabled ? "" : "not ");
@@ -1119,6 +1119,10 @@ static int brcmuart_probe(struct platform_device *pdev)
serial8250_unregister_port(priv->line);
err:
brcmuart_free_bufs(dev, priv);
+err_clk_disable:
+ clk_disable_unprepare(baud_mux_clk);
+err_clk_put:
+ clk_put(baud_mux_clk);
release_dma:
if (priv->dma_enabled)
brcmuart_arbitration(priv, 0);
--
2.34.1


2023-04-24 14:26:29

by Christophe JAILLET

[permalink] [raw]
Subject: Re: [Patch] serial: 8250_bcm7271: fix leak in `brcmuart_probe`

Le 24/04/2023 à 14:51, XuDong Liu a écrit :
> Smatch reports:
> drivers/tty/serial/8250/8250_bcm7271.c:1120 brcmuart_probe() warn:
> 'baud_mux_clk' from clk_prepare_enable() not released on lines: 1032.
>
> In the function brcmuart_probe(), baud_mux_clk was not correctly released
> in subsequent error handling, which may cause memory leaks.
>
> To fix this issue, an error handling branch, err_clk_put, is added to
> release the variable using clk_put(), and an err_disable branch is added
> to meet the requirement of balancing clk_disable and clk_enable calls.
>
> Fixes: 15ac1122fd6d ("serial: 8250_bcm7271: Fix arbitration handling")
> Signed-off-by: XuDong Liu <[email protected]>
> Reviewed-by: Dongliang Mu <[email protected]>
> ---
> The issue is discovered by static analysis, and the patch is not tested
> yet.
> ---
> drivers/tty/serial/8250/8250_bcm7271.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
> index f801b1f5b46c..b1670558868b 100644
> --- a/drivers/tty/serial/8250/8250_bcm7271.c
> +++ b/drivers/tty/serial/8250/8250_bcm7271.c
> @@ -1023,7 +1023,7 @@ static int brcmuart_probe(struct platform_device *pdev)
> dev_dbg(dev, "BAUD MUX clock found\n");
> ret = clk_prepare_enable(baud_mux_clk);
> if (ret)
> - goto release_dma;
> + goto err_clk_put;
> priv->baud_mux_clk = baud_mux_clk;
> init_real_clk_rates(dev, priv);
> clk_rate = priv->default_mux_rate;
> @@ -1032,7 +1032,7 @@ static int brcmuart_probe(struct platform_device *pdev)
> if (clk_rate == 0) {
> dev_err(dev, "clock-frequency or clk not defined\n");
> ret = -EINVAL;
> - goto release_dma;
> + goto err_clk_disable;
> }
>
> dev_dbg(dev, "DMA is %senabled\n", priv->dma_enabled ? "" : "not ");
> @@ -1119,6 +1119,10 @@ static int brcmuart_probe(struct platform_device *pdev)
> serial8250_unregister_port(priv->line);
> err:
> brcmuart_free_bufs(dev, priv);
> +err_clk_disable:
> + clk_disable_unprepare(baud_mux_clk);
> +err_clk_put:
> + clk_put(baud_mux_clk);
> release_dma:
> if (priv->dma_enabled)
> brcmuart_arbitration(priv, 0);

Hi,

it is likely that it should also be added to the rmove function.

CJ

2023-04-27 18:31:48

by Doug Berger

[permalink] [raw]
Subject: Re: [Patch] serial: 8250_bcm7271: fix leak in `brcmuart_probe`

On 4/24/2023 5:51 AM, XuDong Liu wrote:
> Smatch reports:
> drivers/tty/serial/8250/8250_bcm7271.c:1120 brcmuart_probe() warn:
> 'baud_mux_clk' from clk_prepare_enable() not released on lines: 1032.
>
> In the function brcmuart_probe(), baud_mux_clk was not correctly released
> in subsequent error handling, which may cause memory leaks.
>
> To fix this issue, an error handling branch, err_clk_put, is added to
> release the variable using clk_put(), and an err_disable branch is added
> to meet the requirement of balancing clk_disable and clk_enable calls.
>
> Fixes: 15ac1122fd6d ("serial: 8250_bcm7271: Fix arbitration handling")
> Signed-off-by: XuDong Liu <[email protected]>
> Reviewed-by: Dongliang Mu <[email protected]>
> ---
> The issue is discovered by static analysis, and the patch is not tested
> yet.
> ---
> drivers/tty/serial/8250/8250_bcm7271.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
> index f801b1f5b46c..b1670558868b 100644
> --- a/drivers/tty/serial/8250/8250_bcm7271.c
> +++ b/drivers/tty/serial/8250/8250_bcm7271.c
> @@ -1023,7 +1023,7 @@ static int brcmuart_probe(struct platform_device *pdev)
> dev_dbg(dev, "BAUD MUX clock found\n");
> ret = clk_prepare_enable(baud_mux_clk);
> if (ret)
> - goto release_dma;
> + goto err_clk_put;
> priv->baud_mux_clk = baud_mux_clk;
> init_real_clk_rates(dev, priv);
> clk_rate = priv->default_mux_rate;
> @@ -1032,7 +1032,7 @@ static int brcmuart_probe(struct platform_device *pdev)
> if (clk_rate == 0) {
> dev_err(dev, "clock-frequency or clk not defined\n");
> ret = -EINVAL;
> - goto release_dma;
> + goto err_clk_disable;
> }
>
> dev_dbg(dev, "DMA is %senabled\n", priv->dma_enabled ? "" : "not ");
> @@ -1119,6 +1119,10 @@ static int brcmuart_probe(struct platform_device *pdev)
> serial8250_unregister_port(priv->line);
> err:
> brcmuart_free_bufs(dev, priv);
> +err_clk_disable:
> + clk_disable_unprepare(baud_mux_clk);
> +err_clk_put:
> + clk_put(baud_mux_clk);
> release_dma:
> if (priv->dma_enabled)
> brcmuart_arbitration(priv, 0);
Thank you for bringing this to my attention.

-Doug

2023-05-13 10:59:34

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [Patch] serial: 8250_bcm7271: fix leak in `brcmuart_probe`

On Mon, Apr 24, 2023 at 08:51:00PM +0800, XuDong Liu wrote:
> Smatch reports:
> drivers/tty/serial/8250/8250_bcm7271.c:1120 brcmuart_probe() warn:
> 'baud_mux_clk' from clk_prepare_enable() not released on lines: 1032.
>
> In the function brcmuart_probe(), baud_mux_clk was not correctly released
> in subsequent error handling, which may cause memory leaks.
>
> To fix this issue, an error handling branch, err_clk_put, is added to
> release the variable using clk_put(), and an err_disable branch is added
> to meet the requirement of balancing clk_disable and clk_enable calls.
>
> Fixes: 15ac1122fd6d ("serial: 8250_bcm7271: Fix arbitration handling")
> Signed-off-by: XuDong Liu <[email protected]>
> Reviewed-by: Dongliang Mu <[email protected]>
> ---
> The issue is discovered by static analysis, and the patch is not tested
> yet.

Please test it.

thanks,

greg k-h