Re: [PATCH] ipmi: Fix handling of messages with provided receive message pointer

[Guenter Roeck <linux@roeck-us.net>]

On 10/7/25 04:45, Corey Minyard wrote:
> On Mon, Oct 06, 2025 at 01:18:57PM -0700, Guenter Roeck wrote:
>> Prior to commit b52da4054ee0 ("ipmi: Rework user message limit handling"),
>> i_ipmi_request() used to increase the user reference counter if the receive
>> message is provided by the caller of IPMI API functions. This is no longer
>> the case. However, ipmi_free_recv_msg() is still called and decreases the
>> reference counter. This results in the reference counter reaching zero,
>> the user data pointer is released, and all kinds of interesting crashes are
>> seen.
>>
>> Fix the problem by increasing user reference counter if the receive message
>> has been provided by the caller.
> 
> Yes, the only interface that uses this that would matter is the watchdog
> timer, which my tests don't currently cover.  I guess I need to add some
> tests.
> 

Yes, that is the one that is crashing. Sorry, I should have mentioned that.

> Sorry, and thanks for the fix.  It's queued for next release.
> 

Thanks!

Guenter