conf: Fix check for chardev source path

Attempting to use a chardev definition like

  <serial type='unix'>
    <target type='isa-serial'/>
  </serial>

correctly results in an error being reported, since the source
path - a required piece of information - is missing; however,
the very similar

  <serial type='unix'>
    <target type='pci-serial'/>
  </serial>

was happily accepted by libvirt, only to result in libvirtd
crashing as soon as the guest was started.

The issue was caused by checking the chardev's targetType
against whitelisted values from virDomainChrChannelTargetType
without first checking the chardev's deviceType to make sure
it is actually a channel, for which the check makes sense,
rather than a different type of chardev.

The only reason this wasn't spotted earlier is that the
whitelisted values just so happen to correspond to USB and
PCI serial devices and Xen and UML consoles respectively,
all of which are fairly uncommon.

https://bugzilla.redhat.com/show_bug.cgi?id=1609720

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 86199623cc71400538bbfed534f8f5383f1c4420..4cda131254634043bd0db8b252df9c22e6ed7897 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -5467,11 +5467,14 @@ virDomainChrSourceDefValidate(const virDomainChrSourceDef *def,
         break;
 
     case VIR_DOMAIN_CHR_TYPE_UNIX:
-        /* path can be auto generated */
+        /* The source path can be auto generated for certain specific
+         * types of channels, but in most cases we should report an
+         * error if the user didn't provide it */
         if (!def->data.nix.path &&
-            (!chr_def ||
-             (chr_def->targetType != VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_XEN &&
-              chr_def->targetType != VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO))) {
+            !(chr_def &&
+              chr_def->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL &&
+              (chr_def->targetType == VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_XEN ||
+               chr_def->targetType == VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO))) {
             virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                            _("Missing source path attribute for char device"));
             return -1;

diff --git a/tests/qemuxml2argvdata/serial-unix-missing-source.xml b/tests/qemuxml2argvdata/serial-unix-missing-source.xml
new file mode 100644 (file)
index 0000000..1e1221f
--- /dev/null
+++ b/tests/qemuxml2argvdata/serial-unix-missing-source.xml
@@ -0,0 +1,15 @@
+<domain type='qemu'>
+  <name>guest</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>1048576</memory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='aarch64' machine='virt'>hvm</type>
+  </os>
+  <devices>
+    <emulator>/usr/bin/qemu-system-aarch64</emulator>
+    <serial type='unix'>
+      <target type='pci-serial'/>
+    </serial>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 35df63b2ac2d1c34d6f7602b97b23ca84874ee87..949b203998a71598e152c5ba03e908cfdacf56fb 100644 (file)
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1417,6 +1417,7 @@ mymain(void)
     DO_TEST("serial-unix-chardev",
             QEMU_CAPS_DEVICE_ISA_SERIAL);
     DO_TEST_CAPS_LATEST("serial-unix-chardev");
+    DO_TEST_PARSE_ERROR("serial-unix-missing-source", NONE);
     DO_TEST("serial-tcp-chardev",
             QEMU_CAPS_DEVICE_ISA_SERIAL);
     DO_TEST("serial-udp-chardev",