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auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/21 01:43:11 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -45 X-Spam_score: -4.6 X-Spam_bar: ---- X-Spam_report: (-4.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.501, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Paolo Bonzini , qemu-devel@nongnu.org, Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Sat, Sep 19, 2020 at 09:11:39PM +0530, Ani Sinha wrote: > Object property insertion code iterates over an integer to get an unused > index that can be used as an unique name for an object property. This loop > increments the integer value indefinitely. Although very unlikely, this can > still cause an integer overflow. > In this change, we fix the above code by checking against INT_MAX and making > sure that the interger index does not overflow beyond that value. If no > available index is found, the code would cause an assertion failure. This > assertion failure is necessary because the callers of the function do not check > the return value for NULL. If we're going to put a limit on the loop, then lets at least make it a sensible real world limit. INT_MAX is insanely large, as a per-object property count limit, we won't get within many orders of magnitude of that. Even INT8_MAX is probably large enough, but just in case someone has a valid reason for 255 properties, INT16_MAX gives breathing space. If someone needs 65535 properties on a single obj I'd call it a design flaw. > > Signed-off-by: Ani Sinha > --- > qom/object.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/qom/object.c b/qom/object.c > index 00fdf89b3b..62414da67f 100644 > --- a/qom/object.c > +++ b/qom/object.c > @@ -1158,11 +1158,11 @@ object_property_try_add(Object *obj, const char *name, const char *type, > > if (name_len >= 3 && !memcmp(name + name_len - 3, "[*]", 4)) { > int i; > - ObjectProperty *ret; > + ObjectProperty *ret = NULL; > char *name_no_array = g_strdup(name); > > name_no_array[name_len - 3] = '\0'; > - for (i = 0; ; ++i) { > + for (i = 0; i < INT_MAX; ++i) { > char *full_name = g_strdup_printf("%s[%d]", name_no_array, i); > > ret = object_property_try_add(obj, full_name, type, get, set, > @@ -1173,6 +1173,7 @@ object_property_try_add(Object *obj, const char *name, const char *type, > } > } > g_free(name_no_array); > + assert(ret); > return ret; > } > > -- > 2.17.1 > 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 :|