linux-kernel - Re: [PATCH] module: print module name on refcount error

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Message-ID: <ZQNhjhhpG2aN8Xi6@dhcp22.suse.cz>
Date:   Thu, 14 Sep 2023 21:39:58 +0200
From:   Michal Hocko <mhocko@...e.com>
To:     Jean Delvare <jdelvare@...e.de>
Cc:     Luis Chamberlain <mcgrof@...nel.org>,
        linux-modules@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] module: print module name on refcount error

On Mon 28-08-23 14:18:30, Jean Delvare wrote:
[...]
> > > It would likely be better to use refcount_t instead of atomic_t.  
> > 
> > Patches welcomed.
> 
> Michal, do I understand correctly that this would prevent the case our
> customer had (too many gets), but won't make a difference for actual
> too-many-puts situations?


yes, refcount_t cannot protect from too-many-puts because there is not
real way to protect from those AFAICS. At a certain moment you just drop
to 0 and lose your object and all following that is a UAF. But I do not
think this is actually the interesting case at all.
-- 
Michal Hocko
SUSE Labs