From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57581) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aLC7r-0004a7-M7 for qemu-devel@nongnu.org; Mon, 18 Jan 2016 10:53:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aLC7o-0002NA-LS for qemu-devel@nongnu.org; Mon, 18 Jan 2016 10:53:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56255) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aLC7o-0002Ml-Gg for qemu-devel@nongnu.org; Mon, 18 Jan 2016 10:53:48 -0500 From: Gerd Hoffmann Date: Mon, 18 Jan 2016 16:53:42 +0100 Message-Id: <1453132424-15520-3-git-send-email-kraxel@redhat.com> In-Reply-To: <1453132424-15520-1-git-send-email-kraxel@redhat.com> References: <1453132424-15520-1-git-send-email-kraxel@redhat.com> Subject: [Qemu-devel] [PULL 2/4] vnc: clear vs->tlscreds after unparenting it List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Wolfgang Bumiller , Gerd Hoffmann From: Wolfgang Bumiller This pointer should be cleared in vnc_display_close() otherwise a use-after-free can happen when when using the old style 'x509' and 'tls' options rather than a persistent tls-creds -object, by issuing monitor commands to change the vnc server like so: Start with: -vnc unix:test.socket,x509,tls Then use the following monitor command: change vnc unix:test.socket After this the pointer is still set but invalid and a crash can be triggered for instance by issuing the same command a second time which will try to object_unparent() the same pointer again. Signed-off-by: Wolfgang Bumiller Reviewed-by: Daniel P. Berrange Signed-off-by: Gerd Hoffmann --- ui/vnc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/ui/vnc.c b/ui/vnc.c index 54673eb..c2d3773 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -3134,6 +3134,7 @@ static void vnc_display_close(VncDisplay *vs) vs->subauth = VNC_AUTH_INVALID; if (vs->tlscreds) { object_unparent(OBJECT(vs->tlscreds)); + vs->tlscreds = NULL; } g_free(vs->tlsaclname); vs->tlsaclname = NULL; -- 1.8.3.1