In the Linux kernel, the following vulnerability has been resolved: mtd: Fix gluebi NULL pointer dereference caused by ftl notifier If both ftl.ko and gluebi.ko are loaded, the notifier of ftl triggers NULL pointer dereference when trying to access ‘gluebi->desc’ in gluebiread(). ubigluebiinit ubiregistervolumenotifier ubienumeratevolumes ubinotifyall gluebinotify nb->notifiercall() gluebicreate mtddeviceregister mtddeviceparseregister addmtddevice blktransnotifyadd not->add() ftladdmtd tr->addmtd() scanheader mtdread mtdreadoob mtdreadoobstd gluebiread mtd->read() gluebi->desc - NULL Detailed reproduction information available at the Link [1], In the normal case, obtain gluebi->desc in the gluebigetdevice(), and access gluebi->desc in the gluebiread(). However, gluebigetdevice() is not executed in advance in the ftladdmtd() process, which leads to NULL pointer dereference. The solution for the gluebi module is to run jffs2 on the UBI volume without considering working with ftl or mtdblock [2]. Therefore, this problem can be avoided by preventing gluebi from creating the mtdblock device after creating mtd partition of the type MTD_UBIVOLUME.