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

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(a)linux.vnet.ibm.com&gt; Reviewed-by: Boris Fiuczynski <fiuczy(a)linux.vnet.ibm.com&gt; Reviewed-by: Bjoern Walk <bwalk(a)linux.vnet.ibm.com&gt; --- 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); + }