On Fri, Feb 22, 2019 at 03:46:26PM +0200, Alberto Garcia wrote: > There's a race condition in which the tcp_chr_read() ioc handler can > close a connection that is being written to from another thread. > > Running iotest 136 in a loop triggers this problem and crashes QEMU. > > (gdb) bt > #0 0x00005558b842902d in object_get_class (obj=0x0) at qom/object.c:860 > #1 0x00005558b84f92db in qio_channel_writev_full (ioc=0x0, > iov=0x7ffc355decf0, niov=1, fds=0x0, nfds=0, errp=0x0) at io/channel.c:76 > #2 0x00005558b84e0e9e in io_channel_send_full (ioc=0x0, buf=0x5558baf5beb0, > len=138, fds=0x0, nfds=0) at chardev/char-io.c:123 > #3 0x00005558b84e4a69 in tcp_chr_write (chr=0x5558ba460380, > buf=0x5558baf5beb0 "...", len=138) at chardev/char-socket.c:135 > #4 0x00005558b84dca55 in qemu_chr_write_buffer (s=0x5558ba460380, > buf=0x5558baf5beb0 "...", len=138, offset=0x7ffc355dedd0, write_all=false) at > chardev/char.c:112 > #5 0x00005558b84dcbc2 in qemu_chr_write (s=0x5558ba460380, > buf=0x5558baf5beb0 "...", len=138, write_all=false) at chardev/char.c:147 > #6 0x00005558b84dfb26 in qemu_chr_fe_write (be=0x5558ba476610, > buf=0x5558baf5beb0 "...", len=138) at chardev/char-fe.c:42 > #7 0x00005558b8088c86 in monitor_flush_locked (mon=0x5558ba476610) at > monitor.c:406 > #8 0x00005558b8088e8c in monitor_puts (mon=0x5558ba476610, > str=0x5558ba921e49 "") at monitor.c:449 > #9 0x00005558b8089178 in qmp_send_response (mon=0x5558ba476610, > rsp=0x5558bb161600) at monitor.c:498 > #10 0x00005558b808920c in monitor_qapi_event_emit > (event=QAPI_EVENT_SHUTDOWN, qdict=0x5558bb161600) at monitor.c:526 > #11 0x00005558b8089307 in monitor_qapi_event_queue_no_reenter > (event=QAPI_EVENT_SHUTDOWN, qdict=0x5558bb161600) at monitor.c:551 > #12 0x00005558b80896c0 in qapi_event_emit (event=QAPI_EVENT_SHUTDOWN, > qdict=0x5558bb161600) at monitor.c:626 > #13 0x00005558b855f23b in qapi_event_send_shutdown (guest=false, > reason=SHUTDOWN_CAUSE_HOST_QMP_QUIT) at qapi/qapi-events-run-state.c:43 > #14 0x00005558b81911ef in qemu_system_shutdown > (cause=SHUTDOWN_CAUSE_HOST_QMP_QUIT) at vl.c:1837 > #15 0x00005558b8191308 in main_loop_should_exit () at vl.c:1885 > #16 0x00005558b819140d in main_loop () at vl.c:1924 > #17 0x00005558b8198c84 in main (argc=18, argv=0x7ffc355df3f8, > envp=0x7ffc355df490) at vl.c:4665 > > This patch adds a lock to protect tcp_chr_disconnect() and > socket_reconnect_timeout() > > Signed-off-by: Alberto Garcia <be...@igalia.com> > --- > chardev/char-socket.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-)
Reviewed-by: Daniel P. Berrangé <berra...@redhat.com> Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
