Re: [libvirt] [PATCH 6/6] domain_conf: Avoid false positive

Gcc fails to see that virDomainChrGetDomainPtrsInternal always sets pointers to a non NULL value (except for chr device type VIR_DOMAIN_CHR_DEVICE_TYPE_LAST which if occurs, we are in way bigger problem than NULL deref). In file included from conf/domain_conf.c:37:0: conf/domain_conf.c: In function 'virDomainChrPreAlloc': conf/domain_conf.c:14109:35: error: potential null pointer dereference [-Werror=null-dereference] return VIR_REALLOC_N(*arrPtr, *cntPtr + 1); ^~ ./util/viralloc.h:158:73: note: in definition of macro 'VIR_REALLOC_N' # define VIR_REALLOC_N(ptr, count) virReallocN(&(ptr), sizeof(*(ptr)), (count), \ ^~~~~ conf/domain_conf.c: In function 'virDomainChrRemove': conf/domain_conf.c:14133:21: error: potential null pointer dereference [-Werror=null-dereference] for (i = 0; i < *cntPtr; i++) { ^~~~~~~ cc1: all warnings being treated as errors Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/conf/domain_conf.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 3daeb1e..67ed4d7 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -14106,6 +14106,12 @@ virDomainChrPreAlloc(virDomainDefPtr vmdef, virDomainChrGetDomainPtrsInternal(vmdef, chr->deviceType, &arrPtr, &cntPtr); + if (!arrPtr || !cntPtr) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Impossible happened")); + return -1; + } + return VIR_REALLOC_N(*arrPtr, *cntPtr + 1); }