From: Matthew Wilcox <willy@infradead.org>
To: Drew DeVault <sir@cmpwn.com>
Cc: linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
Aleksa Sarai <cyphar@cyphar.com>
Subject: Re: [RFC PATCH] fs: introduce mkdirat2 syscall for atomic mkdir
Date: Sun, 28 Feb 2021 04:03:45 +0000 [thread overview]
Message-ID: <20210228040345.GO2723601@casper.infradead.org> (raw)
In-Reply-To: <C9KT3SWXRPPA.257SY2N4MVBZD@taiga>
On Sat, Feb 27, 2021 at 09:26:21PM -0500, Drew DeVault wrote:
> On Sat Feb 27, 2021 at 9:24 PM EST, Matthew Wilcox wrote:
> > Where's the problem? If mkdir succeeds in a sticky directory, others
> > can't remove or rename it. So how can an app be tricked into doing
> > something wrong?
>
> It's not a security concern, it's just about about making the software
> more robust.
>
> 1. Program A creates a directory
> 2. Program A is pre-empted
> 3. Program B deletes the directory
> 4. Program A creates a file in that directory
> 5. RIP
umm ... program B deletes the directory. program A opens it in order to
use openat(). program A gets ENOENT and exits, confused. that's the
race you're removing here -- and it seems fairly insignificant to me.
next prev parent reply other threads:[~2021-02-28 4:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-28 0:25 [RFC PATCH] fs: introduce mkdirat2 syscall for atomic mkdir Drew DeVault
2021-02-28 2:13 ` Al Viro
2021-02-28 2:21 ` Drew DeVault
2021-02-28 2:58 ` Al Viro
2021-02-28 13:56 ` Drew DeVault
2021-03-01 19:02 ` J. Bruce Fields
2021-03-08 13:50 ` Stefan Metzmacher
2021-02-28 2:24 ` Matthew Wilcox
2021-02-28 2:26 ` Drew DeVault
2021-02-28 4:03 ` Matthew Wilcox [this message]
2021-02-28 13:57 ` Drew DeVault
2021-03-01 19:09 ` J. Bruce Fields
2021-03-01 19:35 ` Matthew Wilcox
2021-03-01 20:10 ` J. Bruce Fields
2021-03-02 8:24 ` Miklos Szeredi
2021-03-02 7:13 ` Amir Goldstein
2021-03-03 2:39 ` Aleksa Sarai
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