From mboxrd@z Thu Jan 1 00:00:00 1970 From: mwilck@suse.com Subject: [PATCH 22/23] multipath: fix leaks in check_path_valid() Date: Thu, 24 Sep 2020 15:40:53 +0200 Message-ID: <20200924134054.14632-23-mwilck@suse.com> References: <20200924134054.14632-1-mwilck@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200924134054.14632-1-mwilck@suse.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Christophe Varoqui , Benjamin Marzinski Cc: lixiaokeng@huawei.com, dm-devel@redhat.com, Martin Wilck List-Id: dm-devel.ids From: Martin Wilck 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. Signed-off-by: Martin Wilck --- multipath/main.c | 55 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 43 insertions(+), 12 deletions(-) diff --git a/multipath/main.c b/multipath/main.c index 049a36f..9974993 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; @@ -592,12 +592,37 @@ out: return r; } +static void cleanup_pathvec(__attribute__((unused)) int dummy, void *arg) +{ + vector *ppv = arg; + + if (ppv && *ppv) { + free_pathvec(*ppv, FREE_PATHS); + *ppv = NULL; + } +} + +static void cleanup_path(__attribute__((unused)) int dummy, void *arg) +{ + struct path **ppp = arg; + + if (ppp && *ppp) { + free_path(*ppp); + *ppp = NULL; + } +} + static int check_path_valid(const char *name, struct config *conf, bool is_uevent) { int fd, r = PATH_IS_ERROR; - struct path *pp = NULL; - vector pathvec = NULL; + static struct path *pp = NULL; + static vector pathvec = NULL; + const char *wwid; + + /* register these as exit handlers in case we exit irregularly */ + on_exit(cleanup_path, &pp); + on_exit(cleanup_pathvec, &pathvec); pp = alloc_path(); if (!pp) @@ -667,13 +692,17 @@ check_path_valid(const char *name, struct config *conf, bool is_uevent) if (store_path(pathvec, pp) != 0) { free_path(pp); 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 @@ -681,21 +710,23 @@ 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 - free_path(pp); - return RTVL_FAIL; + r = RTVL_FAIL; + +cleanup: + cleanup_path(0, &pp); + cleanup_pathvec(0, &pathvec); + return r; } static int -- 2.28.0