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Message-ID: <202405021736.574A688@keescook>
Date: Thu, 2 May 2024 17:41:23 -0700
From: Kees Cook <keescook@...omium.org>
To: Al Viro <viro@...iv.linux.org.uk>
Cc: Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
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Subject: Re: [PATCH 5/5] fs: Convert struct file::f_count to refcount_long_t
On Fri, May 03, 2024 at 01:14:45AM +0100, Al Viro wrote:
> On Thu, May 02, 2024 at 05:10:18PM -0700, Kees Cook wrote:
>
> > But anyway, there needs to be a general "oops I hit 0"-aware form of
> > get_file(), and it seems like it should just be get_file() itself...
>
> ... which brings back the question of what's the sane damage mitigation
> for that. Adding arseloads of never-exercised failure exits is generally
> a bad idea - it's asking for bitrot and making the thing harder to review
> in future.
Linus seems to prefer best-effort error recovery to sprinkling BUG()s
around. But if that's really the solution, then how about get_file()
switching to to use inc_not_zero and BUG on 0?
--
Kees Cook
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