Re: [libvirt] [PATCHv2 1/6] maint: don't leave garbage on early API exit

Several APIs clear out a user input buffer before attempting to populate it; but in a few cases we missed this memset if we detect a reason for an early exit. Note that these APIs check for non-NULL arguments, and exit early with an error message when NULL is passed in; which means that we must be careful to avoid a NULL deref in order to get to that error message. Also, we were inconsistent on the use of sizeof(virType) vs. sizeof(expression); the latter is more robust if we ever change the type of the expression (although such action is unlikely since these types are part of our public API). * src/libvirt.c (virDomainGetInfo, virDomainGetBlockInfo) (virStoragePoolGetInfo, virStorageVolGetInfo) (virDomainGetJobInfo, virDomainGetBlockJobInfo): Move memset before any returns. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- v2 avoid null deref, prefer sizeof(expr) src/libvirt.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-)

@@ -8449,12 +8450,12 @@ virDomainGetBlockInfo(virDomainPtr domain, const char *disk, virResetLastError();

+ memset(info, 0, sizeof(*info)); +

virCheckDomainReturn(domain, -1); virCheckNonNullArgGoto(disk, error); virCheckNonNullArgGoto(info, error); - memset(info, 0, sizeof(virDomainBlockInfo)); - conn = domain->conn; if (conn->driver->domainGetBlockInfo) {