[Cluster-devel] [PATCH] GFS2: Fix potential NULL dereference in gfs2_alloc_inode

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On 02/03/15 16:15, Andrew Price wrote:
> Return NULL when ip is NULL instead of dereferencing it.
>
> Signed-off-by: Andrew Price <anprice@redhat.com>
> ---
>   fs/gfs2/super.c | 13 +++++++------
>   1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
> index 1666382..37c59ee 100644
> --- a/fs/gfs2/super.c
> +++ b/fs/gfs2/super.c
> @@ -1628,12 +1628,13 @@ static struct inode *gfs2_alloc_inode(struct super_block *sb)
>   	struct gfs2_inode *ip;
>   
>   	ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
> -	if (ip) {
> -		ip->i_flags = 0;
> -		ip->i_gl = NULL;
> -		ip->i_rgd = NULL;
> -		ip->i_res = NULL;
> -	}
> +	if (!ip)
> +		return NULL;
> +
> +	ip->i_flags = 0;
> +	ip->i_gl = NULL;
> +	ip->i_rgd = NULL;
> +	ip->i_res = NULL;
>   	return &ip->i_inode;
>   }
>   

I'm not sure that I see the problem here... it should just return NULL 
if ip is NULL, since ip->i_inode is the first element of ip,

Steve.