On Thu, Nov 21, 2019 at 09:58:32AM +0100, Erik Skultety wrote:
Pre-Glib era which used malloc allowed the size of the client-side buffers to be declared as 0, because malloc documents that it can either return 0 or a unique pointer on 0 size allocations. With glib this doesn't work anymore, because glib documents that for such allocation requests NULL is always returned which results in an error in our public API checks server-side. This patch complements the fix in the RPC layer by explicitly erroring out on the following combination of args used by our legacy APIs (their moder equivalents don't suffer from this):
function(caller-allocated-array, size, ...) { if (!caller-allocated-array && size > 0) return error; }
treating everything else as a valid input and potentially let that fail on the server-side rather than client-side.
Signed-off-by: Erik Skultety <eskultet@redhat.com> --- src/internal.h | 13 +++++++++++++ src/libvirt-domain-snapshot.c | 4 ++-- src/libvirt-domain.c | 21 ++++++--------------- src/libvirt-host.c | 2 +- src/libvirt-interface.c | 4 ++-- src/libvirt-network.c | 4 ++-- src/libvirt-nodedev.c | 4 ++-- src/libvirt-nwfilter.c | 2 +- src/libvirt-secret.c | 2 +- src/libvirt-storage.c | 6 +++--- 10 files changed, 33 insertions(+), 29 deletions(-)
@@ -11136,10 +11133,7 @@ virDomainFSFreeze(virDomainPtr dom,
virCheckDomainReturn(dom, -1); virCheckReadOnlyGoto(dom->conn->flags, error); - if (nmountpoints) - virCheckNonNullArgGoto(mountpoints, error); - else - virCheckNullArgGoto(mountpoints, error);
Interesting, so this actually returned an error if you did *not* pass NULL when nmountpoints == 0, so this would be broken if the caller's malloc() returned non-NULL region for size==0
+ virCheckNonNullArrayArgGoto(mountpoints, nmountpoints, error);
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|