From mboxrd@z Thu Jan 1 00:00:00 1970 From: lixiaokeng Subject: [dm-level] upstream-queue-libmultipath: fix memory leak when iscsi login/out and "multipath -r" executed Date: Sat, 25 Jul 2020 13:47:01 +0800 Message-ID: <1694e42f-92e7-e380-bc8c-ac3ec47cafdc@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Language: en-GB 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 , Martin Wilck , Benjamin Marzinski Cc: linfeilong@huawei.com, dm-devel@redhat.com, liuzhiqiang26@huawei.com, lutianxiong@huawei.com List-Id: dm-devel.ids When one iscsi device logs in and logs out with the "multipath -r" executed at the same time, memory leak happens in multipathd process. The reason is following. When "multipath -r" is executed, the path will be free in configure function. Before path_discovery executed, iscsi device logs out. Then path_discovery will not find any path and there is no path in the gvecs->pathvec. When map_discovery function is executed, disassemble_map function will be called. Because gvecs->pathvec->slot is empty and is_deamon is 1, a path will be allocated and is not stored in gvecs->pathvec but store in mpp->pg. But when the mpp is removed and freed by remove_map function, the path will not be free and can't be find anymore. The procedure details given as follows, 1."multipath -r" is executed main ->child ->reconfigure ->configure ->path_discovery //after iscsi logout ->map_discovery ->update_multipath_table ->disassemble_map ->alloc_path 2.then "multipath -r" is executed again main main ->child ->reconfigure ->remove_maps_and_stop_waiters ->remove_maps Here, we delete checking is_deamon. Because whether the process is a daemon process or not, we think the path should be add to gvecs->pathvec. Reported-by: Tianxiong Li Signed-off-by: Lixiaokeng Signed-off-by: Zhiqiang Liu --- libmultipath/dmparser.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libmultipath/dmparser.c b/libmultipath/dmparser.c index b856a07f..d556f642 100644 --- a/libmultipath/dmparser.c +++ b/libmultipath/dmparser.c @@ -315,7 +315,7 @@ int disassemble_map(vector pathvec, char *params, struct multipath *mpp, WWID_SIZE); } /* Only call this in multipath client mode */ - if (!is_daemon && store_path(pathvec, pp)) + if (store_path(pathvec, pp)) goto out1; } else { if (!strlen(pp->wwid) && --