Re: [libvirt] [PATCH v4 09/11] security: Label the external swtpm with SELinux labels

In this patch we label the swtpm process with SELinux labels. We give it the same label as the QEMU process has. We label its state directory and files as well. We restore the old security labels once the swtpm has terminated. The file and process labels now look as follows: Directory: /var/lib/libvirt/swtpm [root@localhost swtpm]# ls -lZ total 4 rwx------. 2 tss tss system_u:object_r:svirt_image_t:s0:c254,c932 4096 Apr 5 16:46 testvm [root@localhost testvm]# ls -lZ total 8 -rw-r--r--. 1 tss tss system_u:object_r:svirt_image_t:s0:c254,c932 3648 Apr 5 16:46 tpm-00.permall The log in /var/log/swtpm/libvirt/qemu is labeled as follows: -rw-r--r--. 1 tss tss system_u:object_r:svirt_image_t:s0:c254,c932 2237 Apr 5 16:46 vtpm.log [root@localhost 485d0004-a48f-436a-8457-8a3b73e28567]# ps auxZ | grep swtpm | grep ctrl | grep -v grep system_u:system_r:svirt_t:s0:c254,c932 tss 25664 0.0 0.0 28172 3892 ? Ss 16:57 0:00 /usr/bin/swtpm socket --daemon --ctrl type=unixio,path=/var/run/libvirt/qemu/swtpm/testvm-swtpm.sock,mode=0660 --tpmstate dir=/var/lib/libvirt/swtpm/testvm/tpm1.2 --log file=/var/log/swtpm/libvirt/qemu/testvm-swtpm.log [root@localhost 485d0004-a48f-436a-8457-8a3b73e28567]# ps auxZ | grep qemu | grep tpm | grep -v grep system_u:system_r:svirt_t:s0:c254,c932 qemu 25669 99.0 0.0 3096704 48500 ? Sl 16:57 3:28 /bin/qemu-system-x86_64 [..]

Signed-off-by: Stefan Berger <stefanb(a)linux.vnet.ibm.com&gt; --- src/libvirt_private.syms | 2 + src/qemu/qemu_tpm.c | 24 +++++- src/security/security_driver.h | 7 ++ src/security/security_manager.c | 36 +++++++++ src/security/security_manager.h | 6 ++ src/security/security_selinux.c | 164 ++++++++++++++++++++++++++++++++++++++++ src/security/security_stack.c | 40 ++++++++++ 7 files changed, 278 insertions(+), 1 deletion(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 75b8932..2ce67e7 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1319,6 +1319,7 @@ virSecurityManagerRestoreImageLabel; virSecurityManagerRestoreInputLabel; virSecurityManagerRestoreMemoryLabel; virSecurityManagerRestoreSavedStateLabel; +virSecurityManagerRestoreTPMLabels; virSecurityManagerSetAllLabel; virSecurityManagerSetChardevLabel; virSecurityManagerSetChildProcessLabel; @@ -1333,6 +1334,7 @@ virSecurityManagerSetProcessLabel; virSecurityManagerSetSavedStateLabel; virSecurityManagerSetSocketLabel; virSecurityManagerSetTapFDLabel; +virSecurityManagerSetTPMLabels; virSecurityManagerStackAddNested; virSecurityManagerTransactionAbort; virSecurityManagerTransactionCommit; diff --git a/src/qemu/qemu_tpm.c b/src/qemu/qemu_tpm.c index 024d24d..62f0146 100644 --- a/src/qemu/qemu_tpm.c +++ b/src/qemu/qemu_tpm.c @@ -684,7 +684,26 @@ qemuExtTPMStartEmulator(virQEMUDriverPtr driver, virCommandSetErrorBuffer(cmd, &errbuf); - if (virCommandRun(cmd, &exitstatus) < 0 || exitstatus != 0) { + if (virSecurityManagerSetTPMLabels(driver->securityManager, + def) < 0) + goto cleanup; + + if (virSecurityManagerSetChildProcessLabel(driver->securityManager, + def, cmd) < 0) + goto cleanup; + + if (virSecurityManagerPreFork(driver->securityManager) < 0) + goto cleanup; + + /* make sure we run this with the appropriate user */ + virCommandSetUID(cmd, cfg->swtpm_user); + virCommandSetGID(cmd, cfg->swtpm_group); + + ret = virCommandRun(cmd, &exitstatus); + + virSecurityManagerPostFork(driver->securityManager); + + if (ret < 0 || exitstatus != 0) { VIR_ERROR(_("Could not start 'swtpm'. exitstatus: %d " "stderr: %s"), exitstatus, errbuf); virReportError(VIR_ERR_INTERNAL_ERROR, @@ -696,6 +715,8 @@ qemuExtTPMStartEmulator(virQEMUDriverPtr driver, ret = 0; cleanup: + if (ret < 0) + virSecurityManagerRestoreTPMLabels(driver->securityManager, def); VIR_FREE(shortName); VIR_FREE(errbuf); virCommandFree(cmd); @@ -741,6 +762,7 @@ qemuExtTPMStop(virQEMUDriverPtr driver, goto cleanup; qemuTPMEmulatorStop(cfg->swtpmStateDir, shortName); + virSecurityManagerRestoreTPMLabels(driver->securityManager, def); break; case VIR_DOMAIN_TPM_TYPE_PASSTHROUGH: case VIR_DOMAIN_TPM_TYPE_LAST: diff --git a/src/security/security_driver.h b/src/security/security_driver.h index 95e7c4d..cbf0ecf 100644 --- a/src/security/security_driver.h +++ b/src/security/security_driver.h @@ -149,6 +149,10 @@ typedef int (*virSecurityDomainRestoreChardevLabel) (virSecurityManagerPtr mgr, virDomainDefPtr def, virDomainChrSourceDefPtr dev_source, bool chardevStdioLogd); +typedef int (*virSecurityDomainSetTPMLabels) (virSecurityManagerPtr mgr, + virDomainDefPtr def); +typedef int (*virSecurityDomainRestoreTPMLabels) (virSecurityManagerPtr mgr, + virDomainDefPtr def); struct _virSecurityDriver { @@ -213,6 +217,9 @@ struct _virSecurityDriver { virSecurityDomainSetChardevLabel domainSetSecurityChardevLabel; virSecurityDomainRestoreChardevLabel domainRestoreSecurityChardevLabel; + + virSecurityDomainSetTPMLabels domainSetSecurityTPMLabels; + virSecurityDomainRestoreTPMLabels domainRestoreSecurityTPMLabels; }; virSecurityDriverPtr virSecurityDriverLookup(const char *name, diff --git a/src/security/security_manager.c b/src/security/security_manager.c index 71f7f59..8683ad7 100644 --- a/src/security/security_manager.c +++ b/src/security/security_manager.c @@ -1204,3 +1204,39 @@ virSecurityManagerRestoreChardevLabel(virSecurityManagerPtr mgr, virReportUnsupportedError(); return -1; } + + +int +virSecurityManagerSetTPMLabels(virSecurityManagerPtr mgr, + virDomainDefPtr vm) +{ + int ret; + + if (mgr->drv->domainSetSecurityTPMLabels) { + virObjectLock(mgr); + ret = mgr->drv->domainSetSecurityTPMLabels(mgr, vm); + virObjectUnlock(mgr); + + return ret; + } + + return 0; +} + + +int +virSecurityManagerRestoreTPMLabels(virSecurityManagerPtr mgr, + virDomainDefPtr vm) +{ + int ret; + + if (mgr->drv->domainRestoreSecurityTPMLabels) { + virObjectLock(mgr); + ret = mgr->drv->domainRestoreSecurityTPMLabels(mgr, vm); + virObjectUnlock(mgr); + + return ret; + } + + return 0; +} diff --git a/src/security/security_manager.h b/src/security/security_manager.h index c36a8b4..e772b61 100644 --- a/src/security/security_manager.h +++ b/src/security/security_manager.h @@ -194,4 +194,10 @@ int virSecurityManagerRestoreChardevLabel(virSecurityManagerPtr mgr, virDomainChrSourceDefPtr dev_source, bool chardevStdioLogd); +int virSecurityManagerSetTPMLabels(virSecurityManagerPtr mgr, + virDomainDefPtr vm); + +int virSecurityManagerRestoreTPMLabels(virSecurityManagerPtr mgr, + virDomainDefPtr vm); + #endif /* VIR_SECURITY_MANAGER_H__ */ diff --git a/src/security/security_selinux.c b/src/security/security_selinux.c index 92e8415..6377fb7 100644 --- a/src/security/security_selinux.c +++ b/src/security/security_selinux.c @@ -3048,6 +3048,167 @@ virSecuritySELinuxDomainSetPathLabel(virSecurityManagerPtr mgr, return virSecuritySELinuxSetFilecon(mgr, path, seclabel->imagelabel); } + +/* + * _virSecuritySELinuxSetFileLabels: + * + * @mgr: the virSecurityManager + * @path: path to a directory or a file + * @seclabel: the security label + * + * Set the file labels on the given path; if the path is a directory + * we label all files found there, including the directory itself, + * otherwise we just label the file. + */ +static int +_virSecuritySELinuxSetFileLabels(virSecurityManagerPtr mgr, + const char *path, + virSecurityLabelDefPtr seclabel) +{ + int ret = 0; + struct dirent *ent; + char *filename = NULL; + DIR *dir; + + if ((ret = virSecuritySELinuxSetFilecon(mgr, path, seclabel->imagelabel))) + return ret; + + if (!virFileIsDir(path)) + return 0; + + if (virDirOpen(&dir, path) < 0) + return -1; + + while ((ret = virDirRead(dir, &ent, path)) > 0) { + if (ent->d_type != DT_REG) + continue; + + if (virAsprintf(&filename, "%s/%s", path, ent->d_name) < 0) { + ret = -1; + break; + } + ret = virSecuritySELinuxSetFilecon(mgr, filename, + seclabel->imagelabel); + VIR_FREE(filename); + if (ret < 0) + break; + } + if (ret < 0) + virReportSystemError(errno, _("Unable to label files under %s"), + path); + + virDirClose(&dir); + + return ret; +} + + +/* + * _virSecuritySELinuxRestoreFileLabels: + * + * @mgr: the virSecurityManager + * @path: path to a directory or a file + * + * Restore the file labels on the given path; if the path is a directory + * we restore all file labels found there, including the label of the + * directory itself, otherwise we just restore the label on the file. + */ +static int +_virSecuritySELinuxRestoreFileLabels(virSecurityManagerPtr mgr, + const char *path) +{ + int ret = 0; + struct dirent *ent; + char *filename = NULL; + DIR *dir; + + if ((ret = virSecuritySELinuxRestoreFileLabel(mgr, path))) + return ret; + + if (!virFileIsDir(path)) + return 0; + + if (virDirOpen(&dir, path) < 0) + return -1; + + while ((ret = virDirRead(dir, &ent, path)) > 0) { + if (ent->d_type != DT_REG) + continue; + + if (virAsprintf(&filename, "%s/%s", path, ent->d_name) < 0) { + ret = -1; + break; + } + ret = virSecuritySELinuxRestoreFileLabel(mgr, filename); + VIR_FREE(filename); + if (ret < 0) + break; + } + if (ret < 0) + virReportSystemError(errno, _("Unable to restore file labels under %s"), + path); + + virDirClose(&dir); + + return ret; +} + + +static int +virSecuritySELinuxSetTPMLabels(virSecurityManagerPtr mgr, + virDomainDefPtr def) +{ + int ret = 0; + virSecurityLabelDefPtr seclabel; + + seclabel = virDomainDefGetSecurityLabelDef(def, SECURITY_SELINUX_NAME); + if (seclabel == NULL) + return 0; + + switch (def->tpm->type) { + case VIR_DOMAIN_TPM_TYPE_PASSTHROUGH: + break; + case VIR_DOMAIN_TPM_TYPE_EMULATOR: + ret = _virSecuritySELinuxSetFileLabels( + mgr, def->tpm->data.emulator.storagepath, + seclabel); + if (ret == 0 && def->tpm->data.emulator.logfile) + ret = _virSecuritySELinuxSetFileLabels( + mgr, def->tpm->data.emulator.logfile, + seclabel); + break; + case VIR_DOMAIN_TPM_TYPE_LAST: + break; + } + + return ret; +} + + +static int +virSecuritySELinuxRestoreTPMLabels(virSecurityManagerPtr mgr, + virDomainDefPtr def) +{ + int ret = 0; + + switch (def->tpm->type) { + case VIR_DOMAIN_TPM_TYPE_PASSTHROUGH: + break; + case VIR_DOMAIN_TPM_TYPE_EMULATOR: + ret = _virSecuritySELinuxRestoreFileLabels( + mgr, def->tpm->data.emulator.storagepath); + if (ret == 0 && def->tpm->data.emulator.logfile) + ret = _virSecuritySELinuxRestoreFileLabels( + mgr, def->tpm->data.emulator.logfile); + break; + case VIR_DOMAIN_TPM_TYPE_LAST: + break; + } + + return ret; +} + + virSecurityDriver virSecurityDriverSELinux = { .privateDataLen = sizeof(virSecuritySELinuxData), .name = SECURITY_SELINUX_NAME, @@ -3107,4 +3268,7 @@ virSecurityDriver virSecurityDriverSELinux = { .domainSetSecurityChardevLabel = virSecuritySELinuxSetChardevLabel, .domainRestoreSecurityChardevLabel = virSecuritySELinuxRestoreChardevLabel, + + .domainSetSecurityTPMLabels = virSecuritySELinuxSetTPMLabels, + .domainRestoreSecurityTPMLabels = virSecuritySELinuxRestoreTPMLabels, }; diff --git a/src/security/security_stack.c b/src/security/security_stack.c index 9615f9f..e37a681 100644 --- a/src/security/security_stack.c +++ b/src/security/security_stack.c @@ -760,6 +760,43 @@ virSecurityStackDomainRestoreChardevLabel(virSecurityManagerPtr mgr, return rc; } + +static int +virSecurityStackSetTPMLabels(virSecurityManagerPtr mgr, + virDomainDefPtr vm) +{ + virSecurityStackDataPtr priv = virSecurityManagerGetPrivateData(mgr); + virSecurityStackItemPtr item = priv->itemsHead; + int rc = 0; + + for (; item; item = item->next) { + if (virSecurityManagerSetTPMLabels(item->securityManager, + vm) < 0) + rc = -1; + } + + return rc; +} + + +static int +virSecurityStackRestoreTPMLabels(virSecurityManagerPtr mgr, + virDomainDefPtr vm) +{ + virSecurityStackDataPtr priv = virSecurityManagerGetPrivateData(mgr); + virSecurityStackItemPtr item = priv->itemsHead; + int rc = 0; + + for (; item; item = item->next) { + if (virSecurityManagerRestoreTPMLabels(item->securityManager, + vm) < 0) + rc = -1; + } + + return rc; +} + + virSecurityDriver virSecurityDriverStack = { .privateDataLen = sizeof(virSecurityStackData), .name = "stack", @@ -822,4 +859,7 @@ virSecurityDriver virSecurityDriverStack = { .domainSetSecurityChardevLabel = virSecurityStackDomainSetChardevLabel, .domainRestoreSecurityChardevLabel = virSecurityStackDomainRestoreChardevLabel, + + .domainSetSecurityTPMLabels = virSecurityStackSetTPMLabels, + .domainRestoreSecurityTPMLabels = virSecurityStackRestoreTPMLabels, };