[libvirt] [PATCH 4/4] rpc: Fix potentially segfaults

[Marc Hartmayer]

We have to allocate first and if, and only if, it was successful we
can set the count. A segfault has occurred in
virNetServerServiceNewPostExecRestart() when VIR_ALLOC_N(svc->socks,
n) has failed, but svc->nsocsk = n was already set. Thus
virObejectUnref(svc) was called and therefore it was possible that
virNetServerServiceDispose was called => segmentation fault.  For
safeness NULL pointer check were added in
virNetServerServiceDispose().

Signed-off-by: Marc Hartmayer <mhartmay at linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy at linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk at linux.vnet.ibm.com>
---
 src/rpc/virnetserverservice.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/rpc/virnetserverservice.c b/src/rpc/virnetserverservice.c
index 1ef0636..006d041 100644
--- a/src/rpc/virnetserverservice.c
+++ b/src/rpc/virnetserverservice.c
@@ -228,9 +228,9 @@ virNetServerServicePtr virNetServerServiceNewUNIX(const char *path,
     svc->tls = virObjectRef(tls);
 #endif
 
-    svc->nsocks = 1;
-    if (VIR_ALLOC_N(svc->socks, svc->nsocks) < 0)
+    if (VIR_ALLOC_N(svc->socks, 1) < 0)
         goto error;
+    svc->nsocks = 1;
 
     if (virNetSocketNewListenUNIX(path,
                                   mask,
@@ -289,9 +289,9 @@ virNetServerServicePtr virNetServerServiceNewFD(int fd,
     svc->tls = virObjectRef(tls);
 #endif
 
-    svc->nsocks = 1;
-    if (VIR_ALLOC_N(svc->socks, svc->nsocks) < 0)
+    if (VIR_ALLOC_N(svc->socks, 1) < 0)
         goto error;
+    svc->nsocks = 1;
 
     if (virNetSocketNewListenFD(fd,
                                 &svc->socks[0]) < 0)
@@ -367,9 +367,9 @@ virNetServerServicePtr virNetServerServiceNewPostExecRestart(virJSONValuePtr obj
         goto error;
     }
 
-    svc->nsocks = n;
-    if (VIR_ALLOC_N(svc->socks, svc->nsocks) < 0)
+    if (VIR_ALLOC_N(svc->socks, n) < 0)
         goto error;
+    svc->nsocks = n;
 
     for (i = 0; i < svc->nsocks; i++) {
         virJSONValuePtr child = virJSONValueArrayGet(socks, i);
@@ -492,9 +492,11 @@ void virNetServerServiceDispose(void *obj)
     virNetServerServicePtr svc = obj;
     size_t i;
 
-    for (i = 0; i < svc->nsocks; i++)
-        virObjectUnref(svc->socks[i]);
-    VIR_FREE(svc->socks);
+    if (svc->socks) {
+        for (i = 0; i < svc->nsocks; i++)
+            virObjectUnref(svc->socks[i]);
+        VIR_FREE(svc->socks);
+    }
 
 #if WITH_GNUTLS
     virObjectUnref(svc->tls);
-- 
2.5.5