Ocfs2 devel - Oct 2019 - [PATCH] ocfs2:fix potential Null Ptr Dereference

On 19/10/10 09:07, Yizhuo wrote:
> Inside function o2hb_region_blocks_store(), to_o2hb_region()
> could return NULL but there's no check before its dereference,
> which is potentially unsafe.
As I described before, this won't happen IMHO.
configfs item is initialized after loading module, so region should
be valid here.


Thanks,
Joseph
> 
> Signed-off-by: Yizhuo <yzhai003 at ucr.edu>
> ---
>  fs/ocfs2/cluster/heartbeat.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
> index a368350d4c27..93f2b540f245 100644
> --- a/fs/ocfs2/cluster/heartbeat.c
> +++ b/fs/ocfs2/cluster/heartbeat.c
> @@ -1628,7 +1628,7 @@ static ssize_t o2hb_region_blocks_store(struct
config_item *item,
>  	unsigned long tmp;
>  	char *p = (char *)page;
>  
> -	if (reg->hr_bdev)
> +	if (!reg || reg->hr_bdev)
>  		return -EINVAL;
>  
>  	tmp = simple_strtoul(p, &p, 0);
>