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Subject: Re: [PATCH v3] staging: rtl8188eu: Fix potential NULL pointer
 dereference of kcalloc
To:     Aditya Pakki <pakki001@umn.edu>
Cc:     kjlu@umn.edu, Larry Finger <Larry.Finger@lwfinger.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Michael Straube <straube.linux@gmail.com>,
        Colin Ian King <colin.king@canonical.com>,
        Hardik Singh Rathore <hardiksingh.k@gmail.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Nathan Chancellor <natechancellor@gmail.com>,
        devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
References: <20190320172142.1305-1-pakki001@umn.edu>
From:   Mukesh Ojha <mojha@codeaurora.org>
Message-ID: <15d1e6c7-01c7-bff6-59de-1dcafb9af082@codeaurora.org>
Date:   Thu, 21 Mar 2019 01:50:50 +0530
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On 3/20/2019 10:51 PM, Aditya Pakki wrote:
> hwxmits is allocated via kcalloc and not checked for failure before its

No need to mention  kcalloc as the other place allocates the memory 
through kmalloc.

Otherwise looks good.
Acked-by: Mukesh Ojha <mojha@codeaurora.org>

> dereference. The patch fixes this problem by returning error upstream
> in rtl8723bs, rtl8188eu.
>
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
>
> ---
> v2: Move signed off above version change log.
> v1: Return error and remove print in case of failure, per Greg
> ---
>   drivers/staging/rtl8188eu/core/rtw_xmit.c    |  9 +++++++--
>   drivers/staging/rtl8188eu/include/rtw_xmit.h |  2 +-
>   drivers/staging/rtl8723bs/core/rtw_xmit.c    | 14 +++++++-------
>   drivers/staging/rtl8723bs/include/rtw_xmit.h |  2 +-
>   4 files changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/staging/rtl8188eu/core/rtw_xmit.c b/drivers/staging/rtl8188eu/core/rtw_xmit.c
> index 1723a47a96b4..952f2ab51347 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_xmit.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_xmit.c
> @@ -174,7 +174,9 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
>   
>   	pxmitpriv->free_xmit_extbuf_cnt = num_xmit_extbuf;
>   
> -	rtw_alloc_hwxmits(padapter);
> +	res = rtw_alloc_hwxmits(padapter);
> +	if (res == _FAIL)
> +		goto exit;
>   	rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry);
>   
>   	for (i = 0; i < 4; i++)
> @@ -1503,7 +1505,7 @@ s32 rtw_xmit_classifier(struct adapter *padapter, struct xmit_frame *pxmitframe)
>   	return res;
>   }
>   
> -void rtw_alloc_hwxmits(struct adapter *padapter)
> +s32 rtw_alloc_hwxmits(struct adapter *padapter)
>   {
>   	struct hw_xmit *hwxmits;
>   	struct xmit_priv *pxmitpriv = &padapter->xmitpriv;
> @@ -1512,6 +1514,8 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
>   
>   	pxmitpriv->hwxmits = kcalloc(pxmitpriv->hwxmit_entry,
>   				     sizeof(struct hw_xmit), GFP_KERNEL);
> +	if (!pxmitpriv->hwxmits)
> +		return _FAIL;
>   
>   	hwxmits = pxmitpriv->hwxmits;
>   
> @@ -1519,6 +1523,7 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
>   	hwxmits[1] .sta_queue = &pxmitpriv->vi_pending;
>   	hwxmits[2] .sta_queue = &pxmitpriv->be_pending;
>   	hwxmits[3] .sta_queue = &pxmitpriv->bk_pending;
> +	return _SUCCESS;
>   }
>   
>   void rtw_free_hwxmits(struct adapter *padapter)
> diff --git a/drivers/staging/rtl8188eu/include/rtw_xmit.h b/drivers/staging/rtl8188eu/include/rtw_xmit.h
> index 788f59c74ea1..ba7e15fbde72 100644
> --- a/drivers/staging/rtl8188eu/include/rtw_xmit.h
> +++ b/drivers/staging/rtl8188eu/include/rtw_xmit.h
> @@ -336,7 +336,7 @@ s32 rtw_txframes_sta_ac_pending(struct adapter *padapter,
>   void rtw_init_hwxmits(struct hw_xmit *phwxmit, int entry);
>   s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter);
>   void _rtw_free_xmit_priv(struct xmit_priv *pxmitpriv);
> -void rtw_alloc_hwxmits(struct adapter *padapter);
> +s32 rtw_alloc_hwxmits(struct adapter *padapter);
>   void rtw_free_hwxmits(struct adapter *padapter);
>   s32 rtw_xmit(struct adapter *padapter, struct sk_buff **pkt);
>   
> diff --git a/drivers/staging/rtl8723bs/core/rtw_xmit.c b/drivers/staging/rtl8723bs/core/rtw_xmit.c
> index 094d61bcb469..b87f13a0b563 100644
> --- a/drivers/staging/rtl8723bs/core/rtw_xmit.c
> +++ b/drivers/staging/rtl8723bs/core/rtw_xmit.c
> @@ -260,7 +260,9 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
>   		}
>   	}
>   
> -	rtw_alloc_hwxmits(padapter);
> +	res = rtw_alloc_hwxmits(padapter);
> +	if (res == _FAIL)
> +		goto exit;
>   	rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry);
>   
>   	for (i = 0; i < 4; i++) {
> @@ -2144,7 +2146,7 @@ s32 rtw_xmit_classifier(struct adapter *padapter, struct xmit_frame *pxmitframe)
>   	return res;
>   }
>   
> -void rtw_alloc_hwxmits(struct adapter *padapter)
> +s32 rtw_alloc_hwxmits(struct adapter *padapter)
>   {
>   	struct hw_xmit *hwxmits;
>   	struct xmit_priv *pxmitpriv = &padapter->xmitpriv;
> @@ -2155,10 +2157,8 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
>   
>   	pxmitpriv->hwxmits = rtw_zmalloc(sizeof(struct hw_xmit) * pxmitpriv->hwxmit_entry);
>   
> -	if (pxmitpriv->hwxmits == NULL) {
> -		DBG_871X("alloc hwxmits fail!...\n");
> -		return;
> -	}
> +	if (!pxmitpriv->hwxmits)
> +		return _FAIL;
>   
>   	hwxmits = pxmitpriv->hwxmits;
>   
> @@ -2204,7 +2204,7 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
>   
>   	}
>   
> -
> +	return _SUCCESS;
>   }
>   
>   void rtw_free_hwxmits(struct adapter *padapter)
> diff --git a/drivers/staging/rtl8723bs/include/rtw_xmit.h b/drivers/staging/rtl8723bs/include/rtw_xmit.h
> index 1b38b9182b31..37f42b2f22f1 100644
> --- a/drivers/staging/rtl8723bs/include/rtw_xmit.h
> +++ b/drivers/staging/rtl8723bs/include/rtw_xmit.h
> @@ -487,7 +487,7 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter);
>   void _rtw_free_xmit_priv (struct xmit_priv *pxmitpriv);
>   
>   
> -void rtw_alloc_hwxmits(struct adapter *padapter);
> +s32 rtw_alloc_hwxmits(struct adapter *padapter);
>   void rtw_free_hwxmits(struct adapter *padapter);
>   
>