Comment 11 for bug 1695789

Valgrind showing wrong memory behavior due to a double free() (explained in this bug)

==10019== Thread 3:
==10019== Invalid read of size 1
==10019== at 0x4C2E0E2: strlen (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==10019== by 0x56FC243: find_mp_by_alias (structs.c:295)
==10019== by 0x571F066: update_multipath (structs_vec.c:495)
==10019== by 0x5720986: waiteventloop (waiter.c:130)
==10019== by 0x5720AE3: waitevent (waiter.c:162)
==10019== by 0x4E3F183: start_thread (pthread_create.c:312)
==10019== by 0x5A2EFFC: clone (clone.S:111)
==10019== Address 0x731ada0 is 0 bytes inside a block of size 6 free'd
==10019== at 0x4C2BDEC: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==10019== by 0x404A9A: uev_add_map (main.c:245)
==10019== by 0x40623C: uev_trigger (main.c:756)
==10019== by 0x5713958: service_uevq (uevent.c:118)
==10019== by 0x5713B67: uevent_dispatch (uevent.c:167)
==10019== by 0x406485: uevqloop (main.c:815)
==10019== by 0x4E3F183: start_thread (pthread_create.c:312)
==10019== by 0x5A2EFFC: clone (clone.S:111)

==10019== Invalid read of size 2
==10019== at 0x4C2FDC0: __GI_memcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==10019== by 0x505DB81: ??? (in /lib/x86_64-linux-gnu/libdevmapper.so.1.02.1)
==10019== by 0x56F50E9: dm_get_status (devmapper.c:402)
==10019== by 0x571E6FF: update_multipath_status (structs_vec.c:262)
==10019== by 0x571E7D9: update_multipath_strings (structs_vec.c:283)
==10019== by 0x571EA57: setup_multipath (structs_vec.c:338)
==10019== by 0x571F0DD: update_multipath (structs_vec.c:505)
==10019== by 0x5720986: waiteventloop (waiter.c:130)
==10019== by 0x5720AE3: waitevent (waiter.c:162)
==10019== by 0x4E3F183: start_thread (pthread_create.c:312)
==10019== by 0x5A2EFFC: clone (clone.S:111)
==10019== Address 0x7e200d0 is 0 bytes inside a block of size 6 free'd
==10019== at 0x4C2BDEC: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==10019== by 0x404A9A: uev_add_map (main.c:245)
==10019== by 0x40623C: uev_trigger (main.c:756)
==10019== by 0x5713958: service_uevq (uevent.c:118)
==10019== by 0x5713B67: uevent_dispatch (uevent.c:167)
==10019== by 0x406485: uevqloop (main.c:815)
==10019== by 0x4E3F183: start_thread (pthread_create.c:312)
==10019== by 0x5A2EFFC: clone (clone.S:111)