[PATCH] net: lan78xx: Fix possible uninit bug

[PATCH] net: lan78xx: Fix possible uninit bug

[Yu Hao]

The variable buf should be initialized in the function lan78xx_read_reg.
However, there is no return value check, which means the variable buf
could still be uninit. But there is a read later.

Signed-off-by: Yu Hao <yhao016@ucr.edu>
---
 drivers/net/usb/lan78xx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index c458c030fadf..4c9318c92fe6 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -1091,8 +1091,11 @@ static int lan78xx_write_raw_otp(struct
lan78xx_net *dev, u32 offset,
    int i;
    u32 buf;
    unsigned long timeout;
+   int ret;

-   lan78xx_read_reg(dev, OTP_PWR_DN, &buf);
+   ret = lan78xx_read_reg(dev, OTP_PWR_DN, &buf);
+   if (ret < 0)
+       return ret;

    if (buf & OTP_PWR_DN_PWRDN_N_) {
        /* clear it and wait to be cleared */
-- 
2.34.1

Re: [PATCH] net: lan78xx: Fix possible uninit bug

[Herve Codina]

On Tue, 4 Jul 2023 18:15:09 -0700
Yu Hao <yhao016@ucr.edu> wrote:

> The variable buf should be initialized in the function lan78xx_read_reg.
> However, there is no return value check, which means the variable buf
> could still be uninit. But there is a read later.
> 
> Signed-off-by: Yu Hao <yhao016@ucr.edu>
> ---
>  drivers/net/usb/lan78xx.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
> index c458c030fadf..4c9318c92fe6 100644
> --- a/drivers/net/usb/lan78xx.c
> +++ b/drivers/net/usb/lan78xx.c
> @@ -1091,8 +1091,11 @@ static int lan78xx_write_raw_otp(struct
> lan78xx_net *dev, u32 offset,
>     int i;
>     u32 buf;
>     unsigned long timeout;
> +   int ret;
> 
> -   lan78xx_read_reg(dev, OTP_PWR_DN, &buf);
> +   ret = lan78xx_read_reg(dev, OTP_PWR_DN, &buf);
> +   if (ret < 0)
> +       return ret;
> 
>     if (buf & OTP_PWR_DN_PWRDN_N_) {
>         /* clear it and wait to be cleared */

Reviewed-by: Herve Codina <herve.codina@bootlin.com>

Best regards,
Hervé

-- 
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH] net: lan78xx: Fix possible uninit bug

[Greg KH]

On Tue, Jul 04, 2023 at 06:15:09PM -0700, Yu Hao wrote:
> The variable buf should be initialized in the function lan78xx_read_reg.
> However, there is no return value check, which means the variable buf
> could still be uninit. But there is a read later.
> 
> Signed-off-by: Yu Hao <yhao016@ucr.edu>
> ---
>  drivers/net/usb/lan78xx.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
> index c458c030fadf..4c9318c92fe6 100644
> --- a/drivers/net/usb/lan78xx.c
> +++ b/drivers/net/usb/lan78xx.c
> @@ -1091,8 +1091,11 @@ static int lan78xx_write_raw_otp(struct
> lan78xx_net *dev, u32 offset,
>     int i;
>     u32 buf;
>     unsigned long timeout;
> +   int ret;
> 
> -   lan78xx_read_reg(dev, OTP_PWR_DN, &buf);
> +   ret = lan78xx_read_reg(dev, OTP_PWR_DN, &buf);
> +   if (ret < 0)
> +       return ret;
> 
>     if (buf & OTP_PWR_DN_PWRDN_N_) {
>         /* clear it and wait to be cleared */
> -- 
> 2.34.1

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
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If you wish to discuss this problem further, or you have questions about
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thanks,

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