[Ocfs2-tools-devel] [PATCH] mkfs.ocfs2: fix a potential segment fault in main()

[Joseph Qi]

On 2016/9/22 20:52, piaojun wrote:
> 's->global_bm' may be NULL in free_state() as 's->global_bm' will be
> initialized later by initialize_bitmap(). So we need judge 'global_bm'
> before access its members. The same problem happens for 'system_group'.
> 
> 'State *s' need to be free in free_state() in case of memory leak.
> 
> Fixes: cec294ef135c ("mkfs.ocfs2: fix memory leak problems in main()")
> 
> Signed-off-by: Jun Piao <piaojun at huawei.com>
Reviewed-by: Joseph Qi <joseph.qi at huawei.com>

> ---
>  mkfs.ocfs2/mkfs.c | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/mkfs.ocfs2/mkfs.c b/mkfs.ocfs2/mkfs.c
> index 8532e12..0997d5b 100644
> --- a/mkfs.ocfs2/mkfs.c
> +++ b/mkfs.ocfs2/mkfs.c
> @@ -1251,13 +1251,16 @@ free_state(State *s)
>  	ocfs2_free(&s->cluster_stack);
>  	ocfs2_free(&s->cluster_name);
>  
> -	for (i = 0; i < s->nr_cluster_groups; i++)
> -		free_alloc_group(s->global_bm->groups[i]);
> -	ocfs2_free(&s->global_bm->groups);
> -	ocfs2_free(&s->global_bm->name);
> -	ocfs2_free(&s->global_bm);
> +	if (s->global_bm) {
> +		for (i = 0; i < s->nr_cluster_groups; i++)
> +			free_alloc_group(s->global_bm->groups[i]);
> +		ocfs2_free(&s->global_bm->groups);
> +		ocfs2_free(&s->global_bm->name);
> +		ocfs2_free(&s->global_bm);
> +	}
>  
>  	free_alloc_group(s->system_group);
> +	ocfs2_free(&s);
>  }
>  
>  static int
> @@ -1877,9 +1880,11 @@ initialize_alloc_group(State *s, const char *name,
>  static void
>  free_alloc_group(AllocGroup *group)
>  {
> -	ocfs2_free(&group->name);
> -	ocfs2_free(&group->gd);
> -	ocfs2_free(&group);
> +	if (group) {
> +		ocfs2_free(&group->name);
> +		ocfs2_free(&group->gd);
> +		ocfs2_free(&group);
> +	}
>  }
>  
>  static AllocBitmap *
>