[PATCH] scsi: lpfc: add null check of kzalloc in lpfc_sli4_cgn_params_read

[PATCH] scsi: lpfc: add null check of kzalloc in lpfc_sli4_cgn_params_read

[Kang Chen]

kzalloc may fails, pdata might be null and it may cause
null pointer dereference later.

Signed-off-by: Kang Chen <void0red@gmail.com>
---
 drivers/scsi/lpfc/lpfc_init.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 6eb4085a3..54134d782 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -7291,6 +7291,8 @@ lpfc_sli4_cgn_params_read(struct lpfc_hba *phba)
 	/* Find out if the FW has a new set of congestion parameters. */
 	len = sizeof(struct lpfc_cgn_param);
 	pdata = kzalloc(len, GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
 	ret = lpfc_read_object(phba, (char *)LPFC_PORT_CFG_NAME,
 			       pdata, len);
 
-- 
2.34.1

Re: [PATCH] scsi: lpfc: add null check of kzalloc in lpfc_sli4_cgn_params_read

[Justin Tee]

Hi Kang,

Thanks for reporting this.

Technically, the lpfc_read_object routine already NULL checks pdata,
and if it was NULL would return -ENODEV.  Then, else if (ret < 0)
would evaluate to true and we'd goto rd_obj_err.

However, we like the suggestion to return -ENOMEM instead.  I will
post a v2 of this patch to address both concerns.

Thanks,
Justin

On Sun, Feb 26, 2023 at 2:48 AM Kang Chen <void0red@gmail.com> wrote:
>
> kzalloc may fails, pdata might be null and it may cause
> null pointer dereference later.
>
> Signed-off-by: Kang Chen <void0red@gmail.com>
> ---
>  drivers/scsi/lpfc/lpfc_init.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
> index 6eb4085a3..54134d782 100644
> --- a/drivers/scsi/lpfc/lpfc_init.c
> +++ b/drivers/scsi/lpfc/lpfc_init.c
> @@ -7291,6 +7291,8 @@ lpfc_sli4_cgn_params_read(struct lpfc_hba *phba)
>         /* Find out if the FW has a new set of congestion parameters. */
>         len = sizeof(struct lpfc_cgn_param);
>         pdata = kzalloc(len, GFP_KERNEL);
> +       if (!pdata)
> +               return -ENOMEM;
>         ret = lpfc_read_object(phba, (char *)LPFC_PORT_CFG_NAME,
>                                pdata, len);
>
> --
> 2.34.1
>