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[PULL 24/30] migration/multifd: fix nullptr access in terminating multif
From: |
Juan Quintela |
Subject: |
[PULL 24/30] migration/multifd: fix nullptr access in terminating multifd threads |
Date: |
Tue, 14 Jan 2020 13:52:48 +0100 |
From: Jiahui Cen <address@hidden>
One multifd channel will shutdown all the other multifd's IOChannel when it
fails to receive an IOChannel. In this senario, if some multifds had not
received its IOChannel yet, it would try to shutdown its IOChannel which could
cause nullptr access at qio_channel_shutdown.
Here is the coredump stack:
#0 object_get_class (obj=obj@entry=0x0) at qom/object.c:908
#1 0x00005563fdbb8f4a in qio_channel_shutdown (ioc=0x0,
how=QIO_CHANNEL_SHUTDOWN_BOTH, errp=0x0) at io/channel.c:355
#2 0x00005563fd7b4c5f in multifd_recv_terminate_threads (err=<optimized
out>) at migration/ram.c:1280
#3 0x00005563fd7bc019 in multifd_recv_new_channel
(ioc=ioc@entry=0x556400255610, errp=errp@entry=0x7ffec07dce00) at
migration/ram.c:1478
#4 0x00005563fda82177 in migration_ioc_process_incoming
(ioc=ioc@entry=0x556400255610, errp=errp@entry=0x7ffec07dce30) at
migration/migration.c:605
#5 0x00005563fda8567d in migration_channel_process_incoming
(ioc=0x556400255610) at migration/channel.c:44
#6 0x00005563fda83ee0 in socket_accept_incoming_migration
(listener=0x5563fff6b920, cioc=0x556400255610, opaque=<optimized out>) at
migration/socket.c:166
#7 0x00005563fdbc25cd in qio_net_listener_channel_func (ioc=<optimized
out>, condition=<optimized out>, opaque=<optimized out>) at io/net-listener.c:54
#8 0x00007f895b6fe9a9 in g_main_context_dispatch () from
/usr/lib64/libglib-2.0.so.0
#9 0x00005563fdc18136 in glib_pollfds_poll () at util/main-loop.c:218
#10 0x00005563fdc181b5 in os_host_main_loop_wait (timeout=1000000000) at
util/main-loop.c:241
#11 0x00005563fdc183a2 in main_loop_wait (nonblocking=nonblocking@entry=0)
at util/main-loop.c:517
#12 0x00005563fd8edb37 in main_loop () at vl.c:1791
#13 0x00005563fd74fd45 in main (argc=<optimized out>, argv=<optimized out>,
envp=<optimized out>) at vl.c:4473
To fix it up, let's check p->c before calling qio_channel_shutdown.
Signed-off-by: Jiahui Cen <address@hidden>
Signed-off-by: Ying Fang <address@hidden>
Reviewed-by: Juan Quintela <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
---
migration/ram.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/migration/ram.c b/migration/ram.c
index aee057f7da..e7cd522173 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1308,7 +1308,9 @@ static void multifd_recv_terminate_threads(Error *err)
- normal quit, i.e. everything went fine, just finished
- error quit: We close the channels so the channel threads
finish the qio_channel_read_all_eof() */
- qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+ if (p->c) {
+ qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+ }
qemu_mutex_unlock(&p->mutex);
}
}
--
2.24.1
- [PULL 14/30] migration: savevm_state_handler_insert: constant-time element insertion, (continued)
- [PULL 14/30] migration: savevm_state_handler_insert: constant-time element insertion, Juan Quintela, 2020/01/14
- [PULL 15/30] migration/ram: Yield periodically to the main loop, Juan Quintela, 2020/01/14
- [PULL 16/30] migration/postcopy: reduce memset when it is zero page and matches_target_page_size, Juan Quintela, 2020/01/14
- [PULL 17/30] migration/postcopy: wait for decompress thread in precopy, Juan Quintela, 2020/01/14
- [PULL 18/30] migration/postcopy: count target page number to decide the place_needed, Juan Quintela, 2020/01/14
- [PULL 19/30] migration/postcopy: set all_zero to true on the first target page, Juan Quintela, 2020/01/14
- [PULL 20/30] migration/postcopy: enable random order target page arrival, Juan Quintela, 2020/01/14
- [PULL 21/30] migration/postcopy: enable compress during postcopy, Juan Quintela, 2020/01/14
- [PULL 22/30] migration/multifd: clean pages after filling packet, Juan Quintela, 2020/01/14
- [PULL 23/30] migration/multifd: not use multifd during postcopy, Juan Quintela, 2020/01/14
- [PULL 24/30] migration/multifd: fix nullptr access in terminating multifd threads,
Juan Quintela <=
- [PULL 25/30] migration/multifd: fix destroyed mutex access in terminating multifd threads, Juan Quintela, 2020/01/14
- [PULL 26/30] Bug #1829242 correction., Juan Quintela, 2020/01/14
- [PULL 27/30] migration: Define VMSTATE_INSTANCE_ID_ANY, Juan Quintela, 2020/01/14
- [PULL 28/30] migration: Change SaveStateEntry.instance_id into uint32_t, Juan Quintela, 2020/01/14
- [PULL 29/30] apic: Use 32bit APIC ID for migration instance ID, Juan Quintela, 2020/01/14
- [PULL 30/30] migration: Support QLIST migration, Juan Quintela, 2020/01/14
- Re: [PULL 00/30] Migration pull patches (take 4), Peter Maydell, 2020/01/17