From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48255) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bUyCi-0005Xk-Ht for qemu-devel@nongnu.org; Wed, 03 Aug 2016 11:35:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bUyCc-0002Ev-Ne for qemu-devel@nongnu.org; Wed, 03 Aug 2016 11:35:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47348) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bUyCc-0002Ej-EI for qemu-devel@nongnu.org; Wed, 03 Aug 2016 11:35:26 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F300EA89A for ; Wed, 3 Aug 2016 15:35:25 +0000 (UTC) From: Gerd Hoffmann Date: Wed, 3 Aug 2016 17:35:21 +0200 Message-Id: <1470238522-28094-3-git-send-email-kraxel@redhat.com> In-Reply-To: <1470238522-28094-1-git-send-email-kraxel@redhat.com> References: <1470238522-28094-1-git-send-email-kraxel@redhat.com> Subject: [Qemu-devel] [PULL 2/3] vnc: fix crash when vnc_server_info_get has an error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Daniel P. Berrange" , Gerd Hoffmann From: "Daniel P. Berrange" 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=) 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=, csock=, skipauth=) at ui/vnc.c:3877 #15 0x0000559193a90c28 in qmp_marshal_add_client (args=, ret=, errp=0x7fffd7899f90) at qmp-marshal.c:105 #16 0x000055919399c2b7 in handle_qmp_command (parser=, tokens=) 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=, size=) at qobject/json-lexer.c:369 #20 0x0000559193ce33c9 in json_message_parser_feed (parser=, buffer=, size=) at qobject/json-streamer.c:124 #21 0x000055919399a85b in monitor_qmp_read (opaque=, buf=, size=) at /home/berrange/src/virt/qemu/monitor.c:3987 #22 0x0000559193a87d00 in tcp_chr_read (chan=, cond=, 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=) at main-loop.c:258 #26 0x0000559193c484b3 in main_loop_wait (nonblocking=) at main-loop.c:506 #27 0x0000559193964c55 in main () at vl.c:1908 #28 0x0000559193964c55 in main (argc=, argv=, envp=) at vl.c:4603 This was introduced in commit 98481bfcd661daa3c160cc87a297b0e60a307788 Author: Eric Blake 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 Message-id: 1470134726-15697-3-git-send-email-berrange@redhat.com Signed-off-by: Gerd Hoffmann --- ui/vnc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ui/vnc.c b/ui/vnc.c index f183d00..f2f5dc1 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; -- 1.8.3.1