Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 2 Nov 2022 12:03:38 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     postix@posteo.eu
Cc:     20221031144850.5522b036@rorschach.local.home,
        linux-kernel@vger.kernel.org, regressions@lists.linux.dev,
        tiwai@suse.de
Subject: Re: [REGRESSION 6.0.x / 6.1.x] NULL dereferencing at tracing
Message-ID: <20221102120338.254741f7@rorschach.local.home>
In-Reply-To: <25d7e982-f959-d86c-a6e7-5efd1db1e75c@posteo.de>
References: <e693eb6b-28d0-d091-3df3-60f2b591c0e7@posteo.de>
        <71829e56-a13f-0462-37a7-a4d64c16f561@posteo.de>
        <25d7e982-f959-d86c-a6e7-5efd1db1e75c@posteo.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Wed,  2 Nov 2022 15:57:56 +0000
postix@posteo.eu 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@rorschach.local.home/

Thanks,

-- Steve