[dm-devel] [PATCH v2 03/17] libmultipath: fix leak in foreign code

[Martin Wilck]

Hi Ben, hi Christophe,

On Wed, 2020-02-05 at 12:58 -0600, Benjamin Marzinski wrote:
> If scandir fails or finds no foreign libraries, enable_re needs to be
> freed before exitting.
> 
> Fixes: 8d03eda4 'multipath.conf: add "enable_foreign" parameter'
> Reviewed-by: Martin Wilck <mwilck at suse.com>
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  libmultipath/foreign.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)

While trying to merge your series into my tree, I realized that this
patch conflicts with my previously submitted patch "libmultipath:
_init_foreign(): fix possible memory leak"
https://www.redhat.com/archives/dm-devel/2019-October/msg00104.html
which fixed the same issue.

The two patches are almost equal, so I really don't care which one
is eventually taken. I just wanted to alert Christophe about the
conflict.

Anyway, I thought that you'd ACK'd my October 72-part patch series in
the following messages:

https://www.redhat.com/archives/dm-devel/2019-October/msg00214.html
  (Ben: ACK on v2 of 72-part series "multipath-tools: cleanup and
warning enablement", except 16/72 "libmultipath: make path_discovery()
pthread_cancel()-safe")
https://www.redhat.com/archives/dm-devel/2019-November/msg00016.html
  (Ben: ACK on 16/72 "libmultipath: make path_discovery()
pthread_cancel()-safe", after discussion)
https://www.redhat.com/archives/dm-devel/2019-November/msg00085.html
  (Ben: Ack on v2->v3 change, updated patch v3 45/72 "libmultipath: fix
-Wsign-compare warnings with snprintf()")

Please clarify if I misunderstood that and the series still needs work
from your PoV.

Regards
Martin


> 
> diff --git a/libmultipath/foreign.c b/libmultipath/foreign.c
> index 4b34e141..68e9a9b8 100644
> --- a/libmultipath/foreign.c
> +++ b/libmultipath/foreign.c
> @@ -129,7 +129,7 @@ static int _init_foreign(const char
> *multipath_dir, const char *enable)
>  	char pathbuf[PATH_MAX];
>  	struct dirent **di;
>  	struct scandir_result sr;
> -	int r, i;
> +	int r, i, ret = 0;
>  	regex_t *enable_re = NULL;
>  
>  	foreigns = vector_alloc();
> @@ -157,13 +157,15 @@ static int _init_foreign(const char
> *multipath_dir, const char *enable)
>  	if (r == 0) {
>  		condlog(3, "%s: no foreign multipath libraries found",
>  			__func__);
> -		return 0;
> +		ret = 0;
> +		goto out;
>  	} else if (r < 0) {
>  		r = errno;
>  		condlog(1, "%s: error %d scanning foreign multipath
> libraries",
>  			__func__, r);
>  		_cleanup_foreign();
> -		return -r;
> +		ret = -r;
> +		goto out;
>  	}
>  
>  	sr.di = di;
> @@ -250,8 +252,9 @@ static int _init_foreign(const char
> *multipath_dir, const char *enable)
>  		free_foreign(fgn);
>  	}
>  	pthread_cleanup_pop(1); /* free_scandir_result */
> +out:
>  	pthread_cleanup_pop(1); /* free_pre */
> -	return 0;
> +	return ret;
>  }
>  
>  int init_foreign(const char *multipath_dir, const char *enable)