From: David Laight <David.Laight@ACULAB.COM>
To: 'Kees Cook' <keescook@chromium.org>,
Ariadne Conill <ariadne@dereferenced.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"Eric Biederman" <ebiederm@xmission.com>,
Alexander Viro <viro@zeniv.linux.org.uk>
Subject: RE: [PATCH] fs/exec: require argv[0] presence in do_execveat_common()
Date: Wed, 26 Jan 2022 16:59:53 +0000 [thread overview]
Message-ID: <a33e8f5318e94e01ac4126bc4870b59a@AcuMS.aculab.com> (raw)
In-Reply-To: <39480927-B17F-4573-B335-7FCFD81AB997@chromium.org>
From: Kees Cook
> Sent: 26 January 2022 07:28
...
> >
> >There shouldn't be anything legitimate actually doing this in userspace.
>
> I spoke too soon.
>
> Unfortunately, this is not the case:
> https://codesearch.debian.net/search?q=execve%5C+*%5C%28%5B%5E%2C%5D%2B%2C+*NULL&literal=0
>
> Lots of stuff likes to do:
> execve(path, NULL, NULL);
>
> Do these things depend on argc==0 would be my next question...
What about ensuring that argv[0] and argv[1] are always present
and both NULL when argc is 0?
Then programs that just scan from argv[1] until they get a NULL
will always be fine.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-01-26 17:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-26 4:39 [PATCH] fs/exec: require argv[0] presence in do_execveat_common() Ariadne Conill
2022-01-26 6:42 ` Kees Cook
2022-01-26 7:28 ` Kees Cook
2022-01-26 11:18 ` Ariadne Conill
2022-01-26 12:33 ` Heikki Kallasjoki
2022-01-26 23:57 ` Kees Cook
2022-01-27 0:20 ` Eric W. Biederman
2022-01-26 16:59 ` David Laight [this message]
2022-01-26 13:27 ` Rich Felker
2022-01-26 14:46 ` Christian Brauner
2022-01-26 17:37 ` Ariadne Conill
2022-02-01 20:54 ` hypervis0r
2022-01-26 15:02 Alexey Dobriyan
2022-01-27 0:00 ` Kees Cook
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