Re: [libvirt] [PATCH] conf: avoid libvirt crash with empty address guestfwd channel
----- Original Message -----
From: "Alex Jia" <ajia(a)redhat.com>
To: libvir-list(a)redhat.com
Cc: "Alex Jia" <ajia(a)redhat.com>
Sent: Friday, September 14, 2012 12:23:56 AM
Subject: [libvirt][PATCH] conf: avoid libvirt crash with empty address guestfwd channel
The 'def->target.addr' hasn't been initialized in virDomainChrDefNew() and
its value is always '0xffffffff', in addition, the following test scenario
hasn't also include 'port' element in channel XML block, so the branch
s/port/address/.
'if (addrStr == NULL)' is hit in virDomainChrDefParseTargetXML(), the
programming jumps to 'error' label to release relevant resources, and the
statement 'if (VIR_ALLOC(def->target.addr) < 0)' hasn't been executed
then
the virDomainChrDefFree() will free 'def->target.addr'(0xffffffff) via
VIR_FREE(), which results in libvirt crash, to use valgrind can also
find a 'Invalid free() / delete / delete[]' error. This patch just adjusts
codes order to initialize 'def->target.addr' firstly.
With this patch, libvirt hasn't crash and can get a expected error message "
XML error: guestfwd channel does not define a target address".
How to reproduce?
1. define a guest with the following channel XML configuration
$ cat foo.xml
<snip>
<channel type='pty'>
<target type='guestfwd'/>
</channel>
</snip>
$ virsh define foo.xml
2. actual result
error: Failed to define domain from /tmp/foo.xml
error: End of file while reading data: Input/output error
error: Failed to reconnect to the hypervisor
GDB debugger information:
<snip>
Breakpoint 1, virDomainChrDefFree (def=0x7f8ab000ec70) at conf/domain_conf.c:1264
...ignore
1264 {
(gdb) p def->target
$2 = {port = -1, addr = 0xffffffff, name = 0xffffffff <Address 0xffffffff out of
bounds>}
</snip>
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=856489
Signed-off-by: Alex Jia <ajia(a)redhat.com>
---
src/conf/domain_conf.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 2f8e5d2..02048c7 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -5231,6 +5231,11 @@ virDomainChrDefParseTargetXML(virCapsPtr caps,
addrStr = virXMLPropString(cur, "address");
portStr = virXMLPropString(cur, "port");
+ if (VIR_ALLOC(def->target.addr) < 0) {
+ virReportOOMError();
+ goto error;
+ }
+
if (addrStr == NULL) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("guestfwd channel does not "
@@ -5238,11 +5243,6 @@ virDomainChrDefParseTargetXML(virCapsPtr caps,
goto error;
}
- if (VIR_ALLOC(def->target.addr) < 0) {
- virReportOOMError();
- goto error;
- }
-
if (virSocketAddrParse(def->target.addr, addrStr, AF_UNSPEC) < 0)
goto error;
--
1.7.1