11:07 a.m.
On 10/11/19 11:08 AM, Michal Privoznik wrote:
On 10/10/19 10:15 PM, Cole Robinson wrote:
> On 10/1/19 11:00 AM, Michal Privoznik wrote:
>> https://bugzilla.redhat.com/show_bug.cgi?id=1755803
>>
>> The /dev/tpmN file can be opened only once, as implemented in
>> drivers/char/tpm/tpm-dev.c:tpm_open() from the kernel's tree. Any
>> other attempt to open the file fails. And since we're opening the
>> file ourselves and passing the FD to qemu we will not succeed
>> opening the file again when locking it for seclabel remembering.
>>
>> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
>> ---
>> src/security/security_dac.c | 18 +++++++++---------
>> src/security/security_selinux.c | 10 +++++-----
>> 2 files changed, 14 insertions(+), 14 deletions(-)
>>
>> diff --git a/src/security/security_dac.c b/src/security/security_dac.c
>> index 2733fa664f..347a7a5f63 100644
>> --- a/src/security/security_dac.c
>> +++ b/src/security/security_dac.c
>> @@ -1653,14 +1653,14 @@
>> virSecurityDACSetTPMFileLabel(virSecurityManagerPtr mgr,
>> switch (tpm->type) {
>> case VIR_DOMAIN_TPM_TYPE_PASSTHROUGH:
>> - ret = virSecurityDACSetChardevLabel(mgr, def,
>> - &tpm->data.passthrough.source,
>> - false);
>> + ret = virSecurityDACSetChardevLabelHelper(mgr, def,
>> + &tpm->data.passthrough.source,
>> + false, false);
>> break;
>> case VIR_DOMAIN_TPM_TYPE_EMULATOR:
>> - ret = virSecurityDACSetChardevLabel(mgr, def,
>> - &tpm->data.emulator.source,
>> - false);
>> + ret = virSecurityDACSetChardevLabelHelper(mgr, def,
>> + &tpm->data.emulator.source,
>> + false, false);
>> break;
>> case VIR_DOMAIN_TPM_TYPE_LAST:
>> break;
>> @@ -1679,9 +1679,9 @@
>> virSecurityDACRestoreTPMFileLabel(virSecurityManagerPtr mgr,
>> switch (tpm->type) {
>> case VIR_DOMAIN_TPM_TYPE_PASSTHROUGH:
>> - ret = virSecurityDACRestoreChardevLabel(mgr, def,
>> - &tpm->data.passthrough.source,
>> - false);
>> + ret = virSecurityDACRestoreChardevLabelHelper(mgr, def,
>> + &tpm->data.passthrough.source,
>> + false, false);
>> break;
>> case VIR_DOMAIN_TPM_TYPE_EMULATOR:
>> /* swtpm will have removed the Unix socket upon termination */
>> diff --git a/src/security/security_selinux.c
>> b/src/security/security_selinux.c
>> index e3be724a2b..0486bdd6b6 100644
>> --- a/src/security/security_selinux.c
>> +++ b/src/security/security_selinux.c
>> @@ -1682,14 +1682,14 @@
>> virSecuritySELinuxSetTPMFileLabel(virSecurityManagerPtr mgr,
>> switch (tpm->type) {
>> case VIR_DOMAIN_TPM_TYPE_PASSTHROUGH:
>> tpmdev = tpm->data.passthrough.source.data.file.path;
>> - rc = virSecuritySELinuxSetFilecon(mgr, tpmdev,
>> seclabel->imagelabel, true);
>> + rc = virSecuritySELinuxSetFilecon(mgr, tpmdev,
>> seclabel->imagelabel, false);
>> if (rc < 0)
>> return -1;
>> if ((cancel_path = virTPMCreateCancelPath(tpmdev)) != NULL) {
>> rc = virSecuritySELinuxSetFilecon(mgr,
>> cancel_path,
>> - seclabel->imagelabel,
>> true);
>> + seclabel->imagelabel,
>> false);
>> VIR_FREE(cancel_path);
>> if (rc < 0) {
>> virSecuritySELinuxRestoreTPMFileLabelInt(mgr, def,
>> tpm);
>> @@ -1701,7 +1701,7 @@
>> virSecuritySELinuxSetTPMFileLabel(virSecurityManagerPtr mgr,
>> break;
>> case VIR_DOMAIN_TPM_TYPE_EMULATOR:
>> tpmdev = tpm->data.emulator.source.data.nix.path;
>> - rc = virSecuritySELinuxSetFilecon(mgr, tpmdev,
>> seclabel->imagelabel, true);
>> + rc = virSecuritySELinuxSetFilecon(mgr, tpmdev,
>> seclabel->imagelabel, false);
>> if (rc < 0)
>> return -1;
>> break;
>
> Are the EMULATOR changes actually required? I think it just uses a
> unix socket and doesn't touch the host kernel tpm subsystem
Well, not per se, because the socket is created on domain startup and
then unlink()-ed on domain shutdown. That's why it doesn't make sense to
try remember anything about the socket.
Okay so it's basically a separate issue from the patch series. In that
case use of virSecurityDACRestoreChardevLabelHelper for EMULATOR is a
bit misleading, and instead virSecurityDACRestoreChardevLabel should
probably grow some smarts to set remember=false for any unix socket path
it sees. But it's a minor distinction because I don't think it matters
in practice given that sockets are unlinked like you say
Thanks,
Cole