Subject: Re: [PATCH] brcmfmac: fix leak of mypkt on error return path
To:     Colin King <colin.king@canonical.com>,
        Franky Lin <franky.lin@broadcom.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        Chi-Hsien Lin <chi-hsien.lin@cypress.com>,
        Wright Feng <wright.feng@cypress.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        "David S . Miller" <davem@davemloft.net>,
        linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com,
        brcm80211-dev-list@cypress.com, netdev@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20190409112011.19546-1-colin.king@canonical.com>
From:   Arend Van Spriel <arend.vanspriel@broadcom.com>
Message-ID: <77f41e34-8358-f22b-615d-15de7c091ff7@broadcom.com>
Date:   Tue, 9 Apr 2019 13:40:39 +0200
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On 4/9/2019 1:20 PM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently if the call to brcmf_sdiod_set_backplane_window fails then
> then error return path leaks mypkt. Fix this by returning by a new
> error path labelled 'out' that calls brcmu_pkt_buf_free_skb to free
> mypkt.
> 
> Addresses-Coverity: ("Resource Leak")
> Fixes: a7c3aa1509e2 ("brcmfmac: Remove brcmf_sdiod_addrprep()")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
> index ec129864cc9c..f3d11e024e71 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
> @@ -628,7 +628,7 @@ int brcmf_sdiod_send_buf(struct brcmf_sdio_dev *sdiodev, u8 *buf, uint nbytes)
>   
>   	err = brcmf_sdiod_set_backplane_window(sdiodev, addr);
>   	if (err)
> -		return err;
> +		goto out;

Actually seems you can just get rid of the if statement entirely as 
below it skips brcmf_sdiod_skbuff_write() when an error occurred so no 
label is necessary.

Regards,
Arend

>   	addr &= SBSDIO_SB_OFT_ADDR_MASK;
>   	addr |= SBSDIO_SB_ACCESS_2_4B_FLAG;
> @@ -636,7 +636,7 @@ int brcmf_sdiod_send_buf(struct brcmf_sdio_dev *sdiodev, u8 *buf, uint nbytes)
>   	if (!err)
>   		err = brcmf_sdiod_skbuff_write(sdiodev, sdiodev->func2, addr,
>   					       mypkt);
> -
> +out:
>   	brcmu_pkt_buf_free_skb(mypkt);
>   
>   	return err;
>