[libvirt] PATCH: Fix double-free in daemon after client connection drop

If a client drops a connection unexpectedly there is a possiblity of a double free in the daemon if using SASL or TLS. This is because there is possibility for poll() on the socket, returns POLLIN and POLLHUP/ERR at the same time. Both the POLLIN and POLLHUP handling code will attempt to use qemudDispatchClientFailure to mark the client as dieing, doing a double free. It is hard to avoid this potential double-invocation of the cleanup function, so it is preferrable to make it safe Daniel diff -rup libvirt-0.6.2.orig/qemud/qemud.c libvirt-0.6.2.new/qemud/qemud.c --- libvirt-0.6.2.orig/qemud/qemud.c 2009-03-13 17:06:16.000000000 +0000 +++ libvirt-0.6.2.new/qemud/qemud.c 2009-05-28 17:58:44.000000000 +0100 @@ -1397,7 +1397,10 @@ static int qemudDispatchServer(struct qe * jobs have finished, then clean it up elsehwere */ void qemudDispatchClientFailure(struct qemud_client *client) { - virEventRemoveHandleImpl(client->watch); + if (client->watch != -1) { + virEventRemoveHandleImpl(client->watch); + client->watch = -1; + } /* Deregister event delivery callback */ if(client->conn) { @@ -1406,12 +1409,21 @@ void qemudDispatchClientFailure(struct q } #if HAVE_SASL - if (client->saslconn) sasl_dispose(&client->saslconn); + if (client->saslconn) { + sasl_dispose(&client->saslconn); + client->saslconn = NULL; + } free(client->saslUsername); + client->saslUsername = NULL; #endif - if (client->tlssession) gnutls_deinit (client->tlssession); - close(client->fd); - client->fd = -1; + if (client->tlssession) { + gnutls_deinit (client->tlssession); + client->tlssession = NULL; + } + if (client->fd != -1) { + close(client->fd); + client->fd = -1; + } } -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|