Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb

Eric Dumazet
2011-05-10T11:52:38Z

Le mardi 10 mai 2011 à 13:19 +0300, Pekka Enberg a écrit :
> On 5/10/11 1:17 PM, Eric Dumazet wrote:
> > Le mardi 10 mai 2011 à 13:03 +0300, Pekka Enberg a écrit :
> >
> >> Can't we fix the issue by putting kmemcheck_mark_initialized() to
> >> set_freepointer()?
> >
> > This would solve kmemcheck problem, not DEBUG_PAGEALLOC
>
> Oh, right. Christoph? We need to support DEBUG_PAGEALLOC with SLUB.

Maybe have a special version of "irqsafe_cpu_cmpxchg_double" and make it
use something like :

local_irq_save(flags);
if (probe_kernel_address(...)) {
res = false;
} else {
res = unsafe_cpu_cmpxchg_double(...)
}
local_irq_restore(flags);

Just the idea, I dont have time to cook a patch.