From ca273df3014930f4ecb6d3ba24aa778354634b56 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Tue, 19 Jun 2018 17:35:52 +0100 Subject: [PATCH] migration: fix crash in when incoming client channel setup fails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The way we determine if we can start the incoming migration was changed to use migration_has_all_channels() in: commit 428d89084c709e568f9cd301c2f6416a54c53d6d Author: Juan Quintela Date: Mon Jul 24 13:06:25 2017 +0200 migration: Create migration_has_all_channels This method in turn calls multifd_recv_all_channels_created() which is hardcoded to always return 'true' when multifd is not in use. This is a latent bug... ...activated in a following commit where that return result ends up acting as the flag to indicate whether it is possible to start processing the migration: commit 36c2f8be2c4eb0003ac77a14910842b7ddd7337e Author: Juan Quintela Date: Wed Mar 7 08:40:52 2018 +0100 migration: Delay start of migration main routines This means that if channel initialization fails with normal migration, it'll never notice and attempt to start the incoming migration regardless and crash on a NULL pointer. This can be seen, for example, if a client connects to a server requiring TLS, but has an invalid x509 certificate: qemu-system-x86_64: The certificate hasn't got a known issuer qemu-system-x86_64: migration/migration.c:386: process_incoming_migration_co: Assertion `mis->from_src_file' failed. #0 0x00007fffebd24f2b in raise () at /lib64/libc.so.6 #1 0x00007fffebd0f561 in abort () at /lib64/libc.so.6 #2 0x00007fffebd0f431 in _nl_load_domain.cold.0 () at /lib64/libc.so.6 #3 0x00007fffebd1d692 in () at /lib64/libc.so.6 #4 0x0000555555ad027e in process_incoming_migration_co (opaque=) at migration/migration.c:386 #5 0x0000555555c45e8b in coroutine_trampoline (i0=, i1=) at util/coroutine-ucontext.c:116 #6 0x00007fffebd3a6a0 in __start_context () at /lib64/libc.so.6 #7 0x0000000000000000 in () To handle the non-multifd case, we check whether mis->from_src_file is non-NULL. With this in place, the migration server drops the rejected client and stays around waiting for another, hopefully valid, client to arrive. Signed-off-by: Daniel P. Berrangé Message-Id: <20180619163552.18206-1-berrange@redhat.com> Reviewed-by: Juan Quintela Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Juan Quintela --- migration/migration.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/migration/migration.c b/migration/migration.c index d075c27886..94d71f8b24 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -518,11 +518,12 @@ void migration_ioc_process_incoming(QIOChannel *ioc) */ bool migration_has_all_channels(void) { + MigrationIncomingState *mis = migration_incoming_get_current(); bool all_channels; all_channels = multifd_recv_all_channels_created(); - return all_channels; + return all_channels && mis->from_src_file != NULL; } /*