Re: [libvirt] [PATCH 3/7] nwfilter_ebiptables_driver.c: avoid NULL dereference

Please respond to "Daniel P. Berrange" On Wed, Apr 14, 2010 at 06:02:32PM +0200, Jim Meyering wrote: > From: Jim Meyering <meyering(a)redhat.com&gt; > > * src/nwfilter/nwfilter_ebiptables_driver.c (ebiptablesApplyNewRules): > Don't dereference a NULL or uninitialized pointer when given > an empty list of rules. Add an sa_assert(inst) in each loop to > tell clang that the uses of "inst[i]" are valid. > --- > src/nwfilter/nwfilter_ebiptables_driver.c | 8 +++++--- > 1 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/src/nwfilter/nwfilter_ebiptables_driver.c b/src/ nwfilter/nwfilter_ebiptables_driver.c > index b481b4c..f54099f 100644 > --- a/src/nwfilter/nwfilter_ebiptables_driver.c > +++ b/src/nwfilter/nwfilter_ebiptables_driver.c > @@ -2834,11 +2834,11 @@ ebiptablesApplyNewRules(virConnectPtr conn ATTRIBUTE_UNUSED, > bool haveIptables = false; > bool haveIp6tables = false; > > - if (inst) > - qsort(inst, nruleInstances, sizeof(inst[0]), > - ebiptablesRuleOrderSort); > + if (nruleInstances > 1 && inst) > + qsort(inst, nruleInstances, sizeof(inst[0]), ebiptablesRuleOrderSort); > > for (i = 0; i < nruleInstances; i++) { > + sa_assert (inst); > if (inst[i]->ruleType == RT_EBTABLES) { > if (inst[i]->chainprefix == CHAINPREFIX_HOST_IN_TEMP) > chains_in |= (1 << inst[i]->neededProtocolChain); > @@ -2881,6 +2881,7 @@ ebiptablesApplyNewRules(virConnectPtr conn ATTRIBUTE_UNUSED, > goto tear_down_tmpebchains; > > for (i = 0; i < nruleInstances; i++) > + sa_assert (inst);