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From: David Laight <David.Laight@ACULAB.COM>
To: 'Kees Cook' <keescook@chromium.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: Ariadne Conill <ariadne@dereferenced.org>,
	Michael Kerrisk <mtk.manpages@gmail.com>,
	Matthew Wilcox <willy@infradead.org>,
	"Christian Brauner" <brauner@kernel.org>,
	Rich Felker <dalias@libc.org>,
	Eric Biederman <ebiederm@xmission.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-hardening@vger.kernel.org"
	<linux-hardening@vger.kernel.org>
Subject: RE: [PATCH] exec: Force single empty string when argv is empty
Date: Tue, 1 Feb 2022 09:17:47 +0000	[thread overview]
Message-ID: <78959c88715049a4be00fc75bb333d3a@AcuMS.aculab.com> (raw)
In-Reply-To: <20220201000947.2453721-1-keescook@chromium.org>

From: Kees Cook
> Sent: 01 February 2022 00:10
...
> While the initial code searches[6][7] turned up what appeared to be
> mostly corner case tests, trying to that just reject argv == NULL
> (or an immediately terminated pointer list) quickly started tripping[8]
> existing userspace programs.
> 
> The next best approach is forcing a single empty string into argv and
> adjusting argc to match. The number of programs depending on argc == 0
> seems a smaller set than those calling execve with a NULL argv.

Has anyone considered using the pathname for argv[0]?
So converting:
	execl(path, NULL);
into:
	execl(path, path, NULL);

I've not spotted any such suggestion.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


  parent reply	other threads:[~2022-02-01  9:17 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-01  0:09 [PATCH] exec: Force single empty string when argv is empty Kees Cook
2022-02-01  1:00 ` Ariadne Conill
2022-02-01  2:00 ` Andy Lutomirski
2022-02-01  9:17 ` David Laight [this message]
2022-02-02 20:31   ` Kees Cook
2022-02-01 13:22 ` Christian Brauner
2022-02-01 14:53 ` Rich Felker
2022-02-02 15:50   ` Kees Cook
2022-02-02 17:12     ` Rich Felker
2022-02-02 19:03       ` Kees Cook

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