Re: New Defects reported by Coverity Scan for QEMU

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

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Hi Dan, Leo,
  There are a few coverity warns from that last series:


Two moans about not checking mkdir in the tls tests:
> ** CID 1488871:  Error handling issues  (CHECKED_RETURN)
> /qemu/tests/qtest/migration-test.c: 782 in test_migrate_tls_x509_start_common()
> 
> 
> ________________________________________________________________________________________________________
> *** CID 1488871:  Error handling issues  (CHECKED_RETURN)
> /qemu/tests/qtest/migration-test.c: 782 in test_migrate_tls_x509_start_common()
> 776         data->servercert = g_strdup_printf("%s/server-cert.pem", data->workdir);
> 777         if (args->clientcert) {
> 778             data->clientkey = g_strdup_printf("%s/client-key.pem", data->workdir);
> 779             data->clientcert = g_strdup_printf("%s/client-cert.pem", data->workdir);
> 780         }
> 781     
> >>>     CID 1488871:  Error handling issues  (CHECKED_RETURN)
> >>>     Calling "mkdir(data->workdir, 448U)" without checking return value. This library function may fail and return an error code.
> 782         mkdir(data->workdir, 0700);
> 783     
> 784         test_tls_init(data->keyfile);
> 785         g_assert(link(data->keyfile, data->serverkey) == 0);
> 786         if (args->clientcert) {
> 787             g_assert(link(data->keyfile, data->clientkey) == 0);
> 
> ** CID 1488870:    (CHECKED_RETURN)
> /qemu/tests/qtest/migration-test.c: 677 in test_migrate_tls_psk_start_common()
> /qemu/tests/qtest/migration-test.c: 670 in test_migrate_tls_psk_start_common()
> 
> 
> ________________________________________________________________________________________________________
> *** CID 1488870:    (CHECKED_RETURN)
> /qemu/tests/qtest/migration-test.c: 677 in test_migrate_tls_psk_start_common()
> 671         test_tls_psk_init(data->pskfile);
> 672     
> 673         if (mismatch) {
> 674             data->workdiralt = g_strdup_printf("%s/tlscredspskalt0", tmpfs);
> 675             data->pskfilealt = g_strdup_printf("%s/%s", data->workdiralt,
> 676                                                QCRYPTO_TLS_CREDS_PSKFILE);
> >>>     CID 1488870:    (CHECKED_RETURN)
> >>>     Calling "mkdir(data->workdiralt, 448U)" without checking return value. This library function may fail and return an error code.
> 677             mkdir(data->workdiralt, 0700);
> 678             test_tls_psk_init_alt(data->pskfilealt);
> 679         }
> 680     
> 681         rsp = wait_command(from,
> 682                            "{ 'execute': 'object-add',"
> /qemu/tests/qtest/migration-test.c: 670 in test_migrate_tls_psk_start_common()
> 664             g_new0(struct TestMigrateTLSPSKData, 1);
> 665         QDict *rsp;
> 666     
> 667         data->workdir = g_strdup_printf("%s/tlscredspsk0", tmpfs);
> 668         data->pskfile = g_strdup_printf("%s/%s", data->workdir,
> 669                                         QCRYPTO_TLS_CREDS_PSKFILE);
> >>>     CID 1488870:    (CHECKED_RETURN)
> >>>     Calling "mkdir(data->workdir, 448U)" without checking return value. This library function may fail and return an error code.
> 670         mkdir(data->workdir, 0700);
> 671         test_tls_psk_init(data->pskfile);
> 672     
> 673         if (mismatch) {
> 674             data->workdiralt = g_strdup_printf("%s/tlscredspskalt0", tmpfs);
> 675             data->pskfilealt = g_strdup_printf("%s/%s", data->workdiralt,
> 
> ** CID 1488869:  Insecure data handling  (TAINTED_SCALAR)
> /qemu/io/channel-socket.c: 716 in qio_channel_socket_flush()



This one is more curious:
> *** CID 1488869:  Insecure data handling  (TAINTED_SCALAR)
> /qemu/io/channel-socket.c: 716 in qio_channel_socket_flush()
> 710         int ret = 1;
> 711     
> 712         msg.msg_control = control;
> 713         msg.msg_controllen = sizeof(control);
> 714         memset(control, 0, sizeof(control));
> 715     
> >>>     CID 1488869:  Insecure data handling  (TAINTED_SCALAR)
> >>>     Using tainted variable "sioc->zero_copy_sent" as a loop boundary.
> 716         while (sioc->zero_copy_sent < sioc->zero_copy_queued) {
> 717             received = recvmsg(sioc->fd, &msg, MSG_ERRQUEUE);
> 718             if (received < 0) {
> 719                 switch (errno) {
> 720                 case EAGAIN:
> 721                     /* Nothing on errqueue, wait until something is available */

it's not clear to me why it considers that 'insecure'; is that because
it's using values returned by the recvmsg ???

Dave

> 
> ** CID 1488868:  Integer handling issues  (OVERFLOW_BEFORE_WIDEN)
> /qemu/include/hw/cxl/cxl_component.h: 218 in cxl_decode_ig()
> 
> 
> ________________________________________________________________________________________________________
> *** CID 1488868:  Integer handling issues  (OVERFLOW_BEFORE_WIDEN)
> /qemu/include/hw/cxl/cxl_component.h: 218 in cxl_decode_ig()
> 212     
> 213     uint8_t cxl_interleave_ways_enc(int iw, Error **errp);
> 214     uint8_t cxl_interleave_granularity_enc(uint64_t gran, Error **errp);
> 215     
> 216     static inline hwaddr cxl_decode_ig(int ig)
> 217     {
> >>>     CID 1488868:  Integer handling issues  (OVERFLOW_BEFORE_WIDEN)
> >>>     Potentially overflowing expression "1 << ig + 8" with type "int" (32 bits, signed) is evaluated using 32-bit arithmetic, and then used in a context that expects an expression of type "hwaddr" (64 bits, unsigned).
> 218         return 1 << (ig + 8);
> 219     }
> 220     
> 221     CXLComponentState *cxl_get_hb_cstate(PCIHostState *hb);
> 222     
> 
> 
> ________________________________________________________________________________________________________
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> 
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-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK