[dm-devel] [PATCH v4 22/29] multipath: fix leaks in check_path_valid()
Benjamin Marzinski
bmarzins at redhat.com
Thu Dec 17 16:32:55 UTC 2020
On Thu, Dec 17, 2020 at 11:04:44AM +0100, mwilck at suse.com wrote:
> From: Martin Wilck <mwilck at suse.com>
>
> There were two leaks in check_path_valid(): if path status was
> successfully determined before calling store_pathvec(), free_path()
> wasn't called. Also, if an error exit occured, neither cleanup
> function was called.
>
> This patch fixes both, at the cost of using "static" for the pp and
> pathvec variables.
>
I just noticed that your commit message doesn't totally match what the
patch does anymore. But the code looks fine. Feel free to change the
message when pushing to upstream-queue.
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>
> Signed-off-by: Martin Wilck <mwilck at suse.com>
> ---
> multipath/main.c | 30 ++++++++++++++++++++----------
> 1 file changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/multipath/main.c b/multipath/main.c
> index 1949a1c..043d8fa 100644
> --- a/multipath/main.c
> +++ b/multipath/main.c
> @@ -93,7 +93,7 @@ void rcu_register_thread_memb(void) {}
> void rcu_unregister_thread_memb(void) {}
>
> static int
> -filter_pathvec (vector pathvec, char * refwwid)
> +filter_pathvec (vector pathvec, const char *refwwid)
> {
> int i;
> struct path * pp;
> @@ -594,8 +594,9 @@ static int
> check_path_valid(const char *name, struct config *conf, bool is_uevent)
> {
> int fd, r = PATH_IS_ERROR;
> - struct path *pp = NULL;
> + struct path *pp;
> vector pathvec = NULL;
> + const char *wwid;
>
> pp = alloc_path();
> if (!pp)
> @@ -664,14 +665,19 @@ check_path_valid(const char *name, struct config *conf, bool is_uevent)
>
> if (store_path(pathvec, pp) != 0) {
> free_path(pp);
> + pp = NULL;
> goto fail;
> + } else {
> + /* make sure path isn't freed twice */
> + wwid = pp->wwid;
> + pp = NULL;
> }
>
> /* For find_multipaths = SMART, if there is more than one path
> * matching the refwwid, then the path is valid */
> if (path_discovery(pathvec, DI_SYSFS | DI_WWID) < 0)
> goto fail;
> - filter_pathvec(pathvec, pp->wwid);
> + filter_pathvec(pathvec, wwid);
> if (VECTOR_SIZE(pathvec) > 1)
> r = PATH_IS_VALID;
> else
> @@ -679,21 +685,25 @@ check_path_valid(const char *name, struct config *conf, bool is_uevent)
>
> out:
> r = print_cmd_valid(r, pathvec, conf);
> - free_pathvec(pathvec, FREE_PATHS);
> /*
> * multipath -u must exit with status 0, otherwise udev won't
> * import its output.
> */
> if (!is_uevent && r == PATH_IS_NOT_VALID)
> - return RTVL_FAIL;
> - return RTVL_OK;
> + r = RTVL_FAIL;
> + else
> + r = RTVL_OK;
> + goto cleanup;
>
> fail:
> - if (pathvec)
> - free_pathvec(pathvec, FREE_PATHS);
> - else
> + r = RTVL_FAIL;
> +
> +cleanup:
> + if (pp != NULL)
> free_path(pp);
> - return RTVL_FAIL;
> + if (pathvec != NULL)
> + free_pathvec(pathvec, FREE_PATHS);
> + return r;
> }
>
> static int
> --
> 2.29.0
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