From 624cdd46d7f67fa2d23e87ffe0a36a569edde11a Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" <berrange@redhat.com> Date: Tue, 2 Aug 2016 11:45:24 +0100 Subject: [PATCH 1/3] vnc: don't crash getting server info if lsock is NULL When VNC is started with '-vnc none' there will be no listener socket present. When we try to populate the VncServerInfo we'll crash accessing a NULL 'lsock' field. #0 qio_channel_socket_get_local_address (ioc=0x0, errp=errp@entry=0x7ffd5b8aa0f0) at io/channel-socket.c:33 #1 0x00007f4b9a297d6f in vnc_init_basic_info_from_server_addr (errp=0x7ffd5b8aa0f0, info=0x7f4b9d425460, ioc=<optimized out>) at ui/vnc.c:146 #2 vnc_server_info_get (vd=0x7f4b9e858000) at ui/vnc.c:223 #3 0x00007f4b9a29d318 in vnc_qmp_event (vs=0x7f4b9ef82000, vs=0x7f4b9ef82000, event=QAPI_EVENT_VNC_CONNECTED) at ui/vnc.c:279 #4 vnc_connect (vd=vd@entry=0x7f4b9e858000, sioc=sioc@entry=0x7f4b9e8b3a20, skipauth=skipauth@entry=true, websocket=websocket @entry=false) at ui/vnc.c:2994 #5 0x00007f4b9a29e8c8 in vnc_display_add_client (id=<optimized out>, csock=<optimized out>, skipauth=<optimized out>) at ui/v nc.c:3825 #6 0x00007f4b9a18d8a1 in qmp_marshal_add_client (args=<optimized out>, ret=<optimized out>, errp=0x7ffd5b8aa230) at qmp-marsh al.c:123 #7 0x00007f4b9a0b53f5 in handle_qmp_command (parser=<optimized out>, tokens=<optimized out>) at /usr/src/debug/qemu-2.6.0/mon itor.c:3922 #8 0x00007f4b9a348580 in json_message_process_token (lexer=0x7f4b9c78dfe8, input=0x7f4b9c7350e0, type=JSON_RCURLY, x=111, y=5 9) at qobject/json-streamer.c:94 #9 0x00007f4b9a35cfeb in json_lexer_feed_char (lexer=lexer@entry=0x7f4b9c78dfe8, ch=125 '}', flush=flush@entry=false) at qobj ect/json-lexer.c:310 #10 0x00007f4b9a35d0ae in json_lexer_feed (lexer=0x7f4b9c78dfe8, buffer=<optimized out>, size=<optimized out>) at qobject/json -lexer.c:360 #11 0x00007f4b9a348679 in json_message_parser_feed (parser=<optimized out>, buffer=<optimized out>, size=<optimized out>) at q object/json-streamer.c:114 #12 0x00007f4b9a0b3a1b in monitor_qmp_read (opaque=<optimized out>, buf=<optimized out>, size=<optimized out>) at /usr/src/deb ug/qemu-2.6.0/monitor.c:3938 #13 0x00007f4b9a186751 in tcp_chr_read (chan=<optimized out>, cond=<optimized out>, opaque=0x7f4b9c7add40) at qemu-char.c:2895 #14 0x00007f4b92b5c79a in g_main_context_dispatch () from /lib64/libglib-2.0.so.0 #15 0x00007f4b9a2bb0c0 in glib_pollfds_poll () at main-loop.c:213 #16 os_host_main_loop_wait (timeout=<optimized out>) at main-loop.c:258 #17 main_loop_wait (nonblocking=<optimized out>) at main-loop.c:506 #18 0x00007f4b9a0835cf in main_loop () at vl.c:1934 #19 main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4667 Do an upfront check for a NULL lsock and report an error to the caller, which matches behaviour from before commit 04d2529da27db512dcbd5e99d0e26d333f16efcc Author: Daniel P. Berrange <berrange@redhat.com> Date: Fri Feb 27 16:20:57 2015 +0000 ui: convert VNC server to use QIOChannelSocket where getsockname() would be given a FD value -1 and thus report an error to the caller. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1470134726-15697-2-git-send-email-berrange@redhat.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- ui/vnc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/ui/vnc.c b/ui/vnc.c index 3ce3a5beec..f183d00deb 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -143,6 +143,11 @@ static void vnc_init_basic_info_from_server_addr(QIOChannelSocket *ioc, { SocketAddress *addr = NULL; + if (!ioc) { + error_setg(errp, "No listener socket available"); + return; + } + addr = qio_channel_socket_get_local_address(ioc, errp); if (!addr) { return; From 3e7f136d8b4383d99f1b034a045b73f9b12a4eae Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" <berrange@redhat.com> Date: Tue, 2 Aug 2016 11:45:25 +0100 Subject: [PATCH 2/3] vnc: fix crash when vnc_server_info_get has an error The vnc_server_info_get will allocate the VncServerInfo struct and then call vnc_init_basic_info_from_server_addr to populate the basic fields. If this returns an error though, the qapi_free_VncServerInfo call will then crash because the VncServerInfo struct instance was not properly NULL-initialized and thus contains random stack garbage. #0 0x00007f1987c8e6f5 in raise () at /lib64/libc.so.6 #1 0x00007f1987c902fa in abort () at /lib64/libc.so.6 #2 0x00007f1987ccf600 in __libc_message () at /lib64/libc.so.6 #3 0x00007f1987cd7d4a in _int_free () at /lib64/libc.so.6 #4 0x00007f1987cdb2ac in free () at /lib64/libc.so.6 #5 0x00007f198b654f6e in g_free () at /lib64/libglib-2.0.so.0 #6 0x0000559193cdcf54 in visit_type_str (v=v@entry= 0x5591972f14b0, name=name@entry=0x559193de1e29 "host", obj=obj@entry=0x5591961dbfa0, errp=errp@entry=0x7fffd7899d80) at qapi/qapi-visit-core.c:255 #7 0x0000559193cca8f3 in visit_type_VncBasicInfo_members (v=v@entry= 0x5591972f14b0, obj=obj@entry=0x5591961dbfa0, errp=errp@entry=0x7fffd7899dc0) at qapi-visit.c:12307 #8 0x0000559193ccb523 in visit_type_VncServerInfo_members (v=v@entry= 0x5591972f14b0, obj=0x5591961dbfa0, errp=errp@entry=0x7fffd7899e00) at qapi-visit.c:12632 #9 0x0000559193ccb60b in visit_type_VncServerInfo (v=v@entry= 0x5591972f14b0, name=name@entry=0x0, obj=obj@entry=0x7fffd7899e48, errp=errp@entry=0x0) at qapi-visit.c:12658 #10 0x0000559193cb53d8 in qapi_free_VncServerInfo (obj=<optimized out>) at qapi-types.c:3970 #11 0x0000559193c1e6ba in vnc_server_info_get (vd=0x7f1951498010) at ui/vnc.c:233 #12 0x0000559193c24275 in vnc_connect (vs=0x559197b2f200, vs=0x559197b2f200, event=QAPI_EVENT_VNC_CONNECTED) at ui/vnc.c:284 #13 0x0000559193c24275 in vnc_connect (vd=vd@entry=0x7f1951498010, sioc=sioc@entry=0x559196bf9c00, skipauth=skipauth@entry=tru e, websocket=websocket@entry=false) at ui/vnc.c:3039 #14 0x0000559193c25806 in vnc_display_add_client (id=<optimized out>, csock=<optimized out>, skipauth=<optimized out>) at ui/vnc.c:3877 #15 0x0000559193a90c28 in qmp_marshal_add_client (args=<optimized out>, ret=<optimized out>, errp=0x7fffd7899f90) at qmp-marshal.c:105 #16 0x000055919399c2b7 in handle_qmp_command (parser=<optimized out>, tokens=<optimized out>) at /home/berrange/src/virt/qemu/monitor.c:3971 #17 0x0000559193ce3307 in json_message_process_token (lexer=0x559194ab0838, input=0x559194a6d940, type=JSON_RCURLY, x=111, y=1 2) at qobject/json-streamer.c:105 #18 0x0000559193cfa90d in json_lexer_feed_char (lexer=lexer@entry=0x559194ab0838, ch=125 '}', flush=flush@entry=false) at qobject/json-lexer.c:319 #19 0x0000559193cfaa1e in json_lexer_feed (lexer=0x559194ab0838, buffer=<optimized out>, size=<optimized out>) at qobject/json-lexer.c:369 #20 0x0000559193ce33c9 in json_message_parser_feed (parser=<optimized out>, buffer=<optimized out>, size=<optimized out>) at qobject/json-streamer.c:124 #21 0x000055919399a85b in monitor_qmp_read (opaque=<optimized out>, buf=<optimized out>, size=<optimized out>) at /home/berrange/src/virt/qemu/monitor.c:3987 #22 0x0000559193a87d00 in tcp_chr_read (chan=<optimized out>, cond=<optimized out>, opaque=0x559194a7d900) at qemu-char.c:2895 #23 0x00007f198b64f703 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0 #24 0x0000559193c484b3 in main_loop_wait () at main-loop.c:213 #25 0x0000559193c484b3 in main_loop_wait (timeout=<optimized out>) at main-loop.c:258 #26 0x0000559193c484b3 in main_loop_wait (nonblocking=<optimized out>) at main-loop.c:506 #27 0x0000559193964c55 in main () at vl.c:1908 #28 0x0000559193964c55 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4603 This was introduced in commit 98481bfcd661daa3c160cc87a297b0e60a307788 Author: Eric Blake <eblake@redhat.com> Date: Mon Oct 26 16:34:45 2015 -0600 vnc: Hoist allocation of VncBasicInfo to callers which added error reporting for vnc_init_basic_info_from_server_addr but didn't change the g_malloc calls to g_malloc0. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1470134726-15697-3-git-send-email-berrange@redhat.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- ui/vnc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ui/vnc.c b/ui/vnc.c index f183d00deb..f2f5dc10af 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -224,7 +224,7 @@ static VncServerInfo *vnc_server_info_get(VncDisplay *vd) VncServerInfo *info; Error *err = NULL; - info = g_malloc(sizeof(*info)); + info = g_malloc0(sizeof(*info)); vnc_init_basic_info_from_server_addr(vd->lsock, qapi_VncServerInfo_base(info), &err); info->has_auth = true; From 12e29b1682e0a50ed57c324152addb585ae5ce69 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" <berrange@redhat.com> Date: Tue, 2 Aug 2016 11:45:26 +0100 Subject: [PATCH 3/3] vnc: ensure connection sharing/limits is always configured The connection sharing / limits are only set in the vnc_display_open() method and so missed when VNC is running with '-vnc none'. This in turn prevents clients being added to the VNC server with the QMP "add_client" command. This was introduced in commit e5f34cdd2da54f28d90889a3afd15fad2d6105ff Author: Gerd Hoffmann <kraxel@redhat.com> Date: Thu Oct 2 12:09:34 2014 +0200 vnc: track & limit connections Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1470134726-15697-4-git-send-email-berrange@redhat.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- ui/vnc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/ui/vnc.c b/ui/vnc.c index f2f5dc10af..4ce903429f 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -3150,6 +3150,9 @@ void vnc_display_init(const char *id) if (!vs->kbd_layout) exit(1); + vs->share_policy = VNC_SHARE_POLICY_ALLOW_EXCLUSIVE; + vs->connections_limit = 32; + qemu_mutex_init(&vs->mutex); vnc_start_worker_thread();