Date: Mon, 15 Dec 2014 13:25:02 +0300
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Cc: Oleg Drokin <oleg.drokin@intel.com>,
        Andreas Dilger <andreas.dilger@intel.com>, devel@driverdev.osuosl.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Brilliantov Kirill Vladimirovich <brilliantov@inbox.ru>,
        linux-kernel@vger.kernel.org, HPDD-discuss@ml01.01.org,
        Greg Donald <gdonald@gmail.com>
Subject: Re: [PATCH] staging: lustre: lustre: osc: lproc_osc.c: Fix for
 possible null pointer dereference
Message-ID: <20141215102502.GB4856@mwanda>
References: <1418596638-24646-1-git-send-email-rickard_strandqvist@spectrumdigital.se>
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On Sun, Dec 14, 2014 at 11:37:18PM +0100, Rickard Strandqvist wrote:
> There is otherwise a risk of a possible null pointer dereference.
> 
> Was largely found by using a static code analysis program called cppcheck.
> 
> Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
> ---
>  drivers/staging/lustre/lustre/osc/lproc_osc.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/lustre/lustre/osc/lproc_osc.c b/drivers/staging/lustre/lustre/osc/lproc_osc.c
> index 9f719bc..9ba6293 100644
> --- a/drivers/staging/lustre/lustre/osc/lproc_osc.c
> +++ b/drivers/staging/lustre/lustre/osc/lproc_osc.c
> @@ -237,13 +237,15 @@ static ssize_t osc_cur_grant_bytes_seq_write(struct file *file, const char *buff
>  				  size_t count, loff_t *off)
>  {
>  	struct obd_device *obd = ((struct seq_file *)file->private_data)->private;
> -	struct client_obd *cli = &obd->u.cli;
> +	struct client_obd *cli;

This isn't really a dereference.  You're just getting the address of
obd->u.cli.  So if obd is NULL then it won't crash.

regards,
dan carpenter

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