[dm-devel] [PATCH 7/7] multipathd: Fix a use-after-free

[Bart Van Assche]

Avoid that Valgrind reports the following:

Invalid read of size 4
   at 0x40C7AE: child (main.c:2382)
   by 0x40D2DC: main (main.c:2608)
 Address 0x7ed255c is 76 bytes inside a block of size 416 free'd
   at 0x4C2E38B: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x5DD37ED: free_config (config.c:539)
   by 0x40B76C: rcu_free_config (main.c:1987)
   by 0x4E3C1FF: call_rcu_thread (urcu-call-rcu-impl.h:332)
   by 0x5047473: start_thread (pthread_create.c:333)
   by 0x671C3EC: clone (clone.S:109)
 Block was alloc'd at
   at 0x4C2D12F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x5DC7D9B: zalloc (memory.c:41)
   by 0x5DD34D7: alloc_config (config.c:472)
   by 0x5DD3A87: load_config (config.c:582)
   by 0x40BF98: child (main.c:2246)
   by 0x40D2DC: main (main.c:2608)

Signed-off-by: Bart Van Assche <bart.vanassche at sandisk.com>
---
 multipathd/main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/multipathd/main.c b/multipathd/main.c
index f4c8245..6a4135c 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -2376,9 +2376,11 @@ child (void * param)
 	}
 
 	lock(vecs->lock);
+	conf = get_multipath_config();
 	if (conf->queue_without_daemon == QUE_NO_DAEMON_OFF)
 		vector_foreach_slot(vecs->mpvec, mpp, i)
 			dm_queue_if_no_path(mpp->alias, 0);
+	put_multipath_config(conf);
 	remove_maps_and_stop_waiters(vecs);
 	unlock(vecs->lock);
 
-- 
2.9.2