Function init_per_cpu() defined in drivers/clk/pxa/clk-pxa.c calls kzalloc() to allocate memory for struct pxa_clk which is dereferenced immediately. As kzalloc() may return NULL when OOM happens, this code piece may cause NULL pointer dereference bug. Codes related to this bug are shown as follows.

drivers/clk/pxa/clk-pxa.c:
  106  	for (i = 0; i < nb_clks; i++) {
  107: 		pxa_clk = kzalloc(sizeof(*pxa_clk), GFP_KERNEL);
  108  		pxa_clk->is_in_low_power = clks[i].is_in_low_power;
  109  		pxa_clk->lp = clks[i].lp;
  110		pxa_clk->hp = clks[i].hp;
  111		pxa_clk->gate = clks[i].gate;
  112		pxa_clk->gate.lock = &pxa_clk_lock;

Thanks for attention!
JW, ZG
IMChecker Group, THU