[PATCH] net-wan: Add check for NULL for utdm in ucc_hdlc_probe

[PATCH] net-wan: Add check for NULL for utdm in ucc_hdlc_probe

[Ekaterina Esina]

If uhdlc_priv_tsa != 1 then utdm is not initialized.
And if ret != NULL then goto undo_uhdlc_init, where utdm is dereferenced.
Same if dev == NULL.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Ekaterina Esina <eesina@astralinux.ru>
---
 drivers/net/wan/fsl_ucc_hdlc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index 22edea6ca4b8..2ddb0f71e648 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -1243,7 +1243,9 @@ static int ucc_hdlc_probe(struct platform_device *pdev)
 free_dev:
 	free_netdev(dev);
 undo_uhdlc_init:
-	iounmap(utdm->siram);
+	if (utdm != NULL) {
+		iounmap(utdm->siram);
+	}
 unmap_si_regs:
 	iounmap(utdm->si_regs);
 free_utdm:
-- 
2.30.2

Re: [lvc-project] [PATCH] net-wan: Add check for NULL for utdm in ucc_hdlc_probe

[Alexey Khoroshilov]

On 23.12.2022 17:32, Ekaterina Esina wrote:
> If uhdlc_priv_tsa != 1 then utdm is not initialized.
> And if ret != NULL then goto undo_uhdlc_init, where utdm is dereferenced.
> Same if dev == NULL.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Signed-off-by: Ekaterina Esina <eesina@astralinux.ru>
> ---
>  drivers/net/wan/fsl_ucc_hdlc.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
> index 22edea6ca4b8..2ddb0f71e648 100644
> --- a/drivers/net/wan/fsl_ucc_hdlc.c
> +++ b/drivers/net/wan/fsl_ucc_hdlc.c
> @@ -1243,7 +1243,9 @@ static int ucc_hdlc_probe(struct platform_device *pdev)
>  free_dev:
>  	free_netdev(dev);
>  undo_uhdlc_init:
> -	iounmap(utdm->siram);
> +	if (utdm != NULL) {
> +		iounmap(utdm->siram);
> +	}
>  unmap_si_regs:
>  	iounmap(utdm->si_regs);
>  free_utdm:


But what is about iounmap(utdm->si_regs); that dereferences utdm a few
lines below?

--
Alexey

Re: [PATCH] net-wan: Add check for NULL for utdm in ucc_hdlc_probe

[Christophe Leroy]

Le 23/12/2022 à 15:32, Ekaterina Esina a écrit :
> [Vous ne recevez pas souvent de courriers de eesina@astralinux.ru. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
> 
> If uhdlc_priv_tsa != 1 then utdm is not initialized.
> And if ret != NULL then goto undo_uhdlc_init, where utdm is dereferenced.
> Same if dev == NULL.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Signed-off-by: Ekaterina Esina <eesina@astralinux.ru>
> ---
>   drivers/net/wan/fsl_ucc_hdlc.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
> index 22edea6ca4b8..2ddb0f71e648 100644
> --- a/drivers/net/wan/fsl_ucc_hdlc.c
> +++ b/drivers/net/wan/fsl_ucc_hdlc.c
> @@ -1243,7 +1243,9 @@ static int ucc_hdlc_probe(struct platform_device *pdev)
>   free_dev:
>          free_netdev(dev);
>   undo_uhdlc_init:
> -       iounmap(utdm->siram);
> +       if (utdm != NULL) {
> +               iounmap(utdm->siram);
> +       }

If utdm being NULL is a problem here, isn't it also a problem in the 
iounmap below ?


>   unmap_si_regs:
>          iounmap(utdm->si_regs);
>   free_utdm:
> --
> 2.30.2
>