Re: [REGRESSION 6.0.x / 6.1.x] NULL dereferencing at tracing

From: Steven Rostedt
Date: Wed Nov 02 2022 - 12:04:39 EST


On Wed, 2 Nov 2022 15:57:56 +0000
postix@xxxxxxxxx wrote:

> Hello everyone,
>
> I have added lot's of debug printk's to see what's happening and I found
> that the "cpu" counter, which is used to access the buffer's array
> elements (cpu_buffer = buffer->buffers[cpu]) in the ring_buffer_wake_waiters
> function, exceeds the maximum number of total of total cores, namely in
> my case 24, which means, it should only run from 0..23. However, upon
> debugging, it runs up to 31, and thus causing a NULL pointer dereference
> (&cpu_buffer->irq_work).
>

Could you add this patch.

https://lore.kernel.org/all/20221101191009.1e7378c8@xxxxxxxxxxxxxxxxxxxx/

Thanks,

-- Steve