[libvirt] [PATCH] Memory Leak Fix: Check def->info->alias before assigning

[Nehal J Wani]

> The 'alias' attribute should *not* be parsed from the XML provided by
> the user. It should only be parsed in the live state XML. In the latter
> case no codepath should take us to qemuAssignDeviceAliases. So this is
> certainly not the right fix. It sounds like the test case is flawed to
> me.
So, I gave it another round to test the remaining error thrown by
valgrind. Here is my finding:

One of the errors received while running valgrind is (not fixed by the
patch given before):

==3915== 9 bytes in 1 blocks are definitely lost in loss record 31 of 129
==3915==    at 0x4A0887C: malloc (vg_replace_malloc.c:270)
    ==3915==    by 0x34268AF275: xmlStrndup (in /usr/lib64/libxml2.so.2.9.1)
    ==3915==    by 0x4CCD393: virDomainDeviceInfoParseXML.isra.31
(domain_conf.c:3439)
    ==3915==    by 0x4CD6A49: virDomainChrDefParseXML (domain_conf.c:7258)
    ==3915==    by 0x4CEC0C9: virDomainDeviceDefParse (domain_conf.c:9616)
    ==3915==    by 0x41D14F: testQemuHotplug (qemuhotplugtest.c:247)
    ==3915==    by 0x41E421: virtTestRun (testutils.c:139)
    ==3915==    by 0x41C6E3: mymain (qemuhotplugtest.c:428)
    ==3915==    by 0x41EAB2: virtTestMain (testutils.c:600)
    ==3915==    by 0x341F421A04: (below main) (libc-start.c:225)

The corresponding fix is:

diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index ec3b958..b7d5390 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -5384,7 +5384,7 @@ qemuMonitorJSONAttachCharDev(qemuMonitorPtr mon,
             goto cleanup;
         }

-        if (VIR_STRDUP(chr->data.file.path, path) < 0)
+        if (!chr->data.file.path && VIR_STRDUP(chr->data.file.path, path) < 0)
             goto cleanup;
     }


But I can't confirm whether the testcase is wrong in this case too.

-- 
Nehal J Wani