[dm-devel] [PATCH] libmultipath: free pp if store_path fails in disassemble_map

[Benjamin Marzinski]

On Wed, Jul 22, 2020 at 04:41:28PM +0800, Zhiqiang Liu wrote:
> In disassemble_map func, one pp will be allocated and stored in pathvec
> (only in client mode) and pgp->paths. However, if store_path fails, pp
> will not be freed, then memory leak problem occurs.
> 
> Here, we will call free_path to free pp when store_path fails.
> 

Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>

However, this will need to get reworked on top of Martin's patches (or
incorporated into his next verion patchset).

-Ben

> Signed-off-by: Zhiqiang Liu <liuzhiqiang26 at huawei.com>
> Signed-off-by: lixiaokeng <lixiaokeng at huawei.com>
> ---
>  libmultipath/dmparser.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/libmultipath/dmparser.c b/libmultipath/dmparser.c
> index 6225838b..3dc77242 100644
> --- a/libmultipath/dmparser.c
> +++ b/libmultipath/dmparser.c
> @@ -142,6 +142,7 @@ int disassemble_map(vector pathvec, char *params, struct multipath *mpp,
>  	int def_minio = 0;
>  	struct path * pp;
>  	struct pathgroup * pgp;
> +	int pp_need_free_flag = 0;
> 
>  	p = params;
> 
> @@ -293,6 +294,7 @@ int disassemble_map(vector pathvec, char *params, struct multipath *mpp,
>  			char devname[FILE_NAME_SIZE];
> 
>  			pp = NULL;
> +			pp_need_free_flag = 0;
>  			p += get_word(p, &word);
> 
>  			if (!word)
> @@ -323,9 +325,15 @@ int disassemble_map(vector pathvec, char *params, struct multipath *mpp,
>  					strncpy(pp->wwid, mpp->wwid,
>  						WWID_SIZE - 1);
>  				}
> +
> +				if (is_daemon)
> +					pp_need_free_flag = 1;
> +
>  				/* Only call this in multipath client mode */
> -				if (!is_daemon && store_path(pathvec, pp))
> +				if (!is_daemon && store_path(pathvec, pp)) {
> +					free_path(pp);
>  					goto out1;
> +				}
>  			} else {
>  				if (!strlen(pp->wwid) &&
>  				    strlen(mpp->wwid))
> @@ -334,8 +342,11 @@ int disassemble_map(vector pathvec, char *params, struct multipath *mpp,
>  			}
>  			FREE(word);
> 
> -			if (store_path(pgp->paths, pp))
> +			if (store_path(pgp->paths, pp)) {
> +				if (pp_need_free_flag)
> +					free_path(pp);
>  				goto out;
> +			}
> 
>  			/*
>  			 * Update wwid for multipaths which are not setup
> -- 
> 2.24.0.windows.2
>