Linux Kernel GRED Scheduler NULL Pointer Dereference Vulnerability

A potential NULL pointer dereference vulnerability has been identified in the GRED scheduler of the Linux kernel. If the memory allocation function 'kzalloc' in 'gred_init' fails and returns a NULL pointer, the error handling process invokes 'gred_destroy'. This subsequently calls 'gred_offload', where a NULL pointer could be passed to 'memset', potentially causing a kernel crash. The issue arises because 'gred_change_table_def' is not called when 'table->opt' is NULL in 'gred_init', making it unnecessary to invoke '->ndo_setup_tc()' in 'gred_offload'.

Impact

Exploitation of this vulnerability could lead to a kernel crash, causing a denial of service.