linux-kernel - Re: [PATCH v3] fs: introduce pipe-only dump mode suid

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20120622125551.269552c2.akpm@linux-foundation.org>
Date:	Fri, 22 Jun 2012 12:55:51 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Kees Cook <keescook@...omium.org>
Cc:	linux-kernel@...r.kernel.org, Alan Cox <alan@...ux.intel.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Rob Landley <rob@...dley.net>, Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Doug Ledford <dledford@...hat.com>,
	Marcel Holtmann <marcel@...tmann.org>,
	Serge Hallyn <serge.hallyn@...onical.com>,
	Joe Korty <joe.korty@...r.com>,
	David Howells <dhowells@...hat.com>,
	James Morris <james.l.morris@...cle.com>,
	linux-doc@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH v3] fs: introduce pipe-only dump mode suid_dumpable=3

On Fri, 22 Jun 2012 12:24:13 -0700
Kees Cook <keescook@...omium.org> wrote:

> The value
> of suid_dumpable=2 is now historic, and attempting to set this sysctl
> value returns -EINVAL.

This sounds a bit harsh - will it not cause existing configurations to
immediately break?  If so, would it not be better to retain the =2 mode
for a while, and emit a nice warning when it is set?

>
> ...
>
> +/* Allow only the valid suid_dumpable values. */
> +static int do_proc_dointvec_suid_dumpable_conv(bool *negp,
> +		unsigned long *lvalp, int *valp, int write, void *data)
> +{
> +	if (write) {
> +		int val = *negp ? -*lvalp : *lvalp;
> +		if (val != SUID_DUMPABLE_DISABLED &&
> +		    val != SUID_DUMPABLE_ENABLED &&
> +		    val != SUID_DUMPABLE_PIPE_ONLY)
> +			return -EINVAL;
> +		*valp = val;
> +	} else {
> +		int val = *valp;
> +		if (val < 0) {
> +			*negp = true;
> +			*lvalp = (unsigned long)-val;
> +		} else {
> +			*negp = false;
> +			*lvalp = (unsigned long)val;

Those two typecasts are unneeded.

> +		}
> +	}
> +	return 0;
> +}
> +

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/