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From: Richard Weinberger <richard@nod.at>
To: "Eric W. Biederman" <ebiederm@xmission.com>,
	David Miller <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>,
	"kernel-hardening@lists.openwall.com"
	<kernel-hardening@lists.openwall.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	bridge@lists.linux-foundation.org,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [Bridge] [PATCH net] bridge: Only call /sbin/bridge-stp for the initial network namespace
Date: Mon, 30 Nov 2015 23:57:29 +0100	[thread overview]
Message-ID: <565CD459.6010402@nod.at> (raw)
In-Reply-To: <87egf7183c.fsf_-_@x220.int.ebiederm.org>

Am 30.11.2015 um 22:38 schrieb Eric W. Biederman:
> 
> There is no defined mechanism to pass network namespace information
> into /sbin/bridge-stp therefore don't even try to invoke it except
> for bridge devices in the initial network namespace.
> 
> It is possible for unprivileged users to cause /sbin/bridge-stp to be
> invoked for any network device name which if /sbin/bridge-stp does not
> guard against unreasonable arguments or being invoked twice on the same
> network device could cause problems.
> 
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Just figured that /sbin/bridge-stp is a shell script.
Network interfaces can contain a lot of funny characters,
maybe this is after all a security issue.

Thanks,
//richard


WARNING: multiple messages have this Message-ID (diff)
From: Richard Weinberger <richard@nod.at>
To: "Eric W. Biederman" <ebiederm@xmission.com>,
	David Miller <davem@davemloft.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"kernel-hardening@lists.openwall.com"
	<kernel-hardening@lists.openwall.com>,
	bridge@lists.linux-foundation.org,
	Stephen Hemminger <stephen@networkplumber.org>,
	Kees Cook <keescook@chromium.org>
Subject: [kernel-hardening] Re: [PATCH net] bridge: Only call /sbin/bridge-stp for the initial network namespace
Date: Mon, 30 Nov 2015 23:57:29 +0100	[thread overview]
Message-ID: <565CD459.6010402@nod.at> (raw)
In-Reply-To: <87egf7183c.fsf_-_@x220.int.ebiederm.org>

Am 30.11.2015 um 22:38 schrieb Eric W. Biederman:
> 
> There is no defined mechanism to pass network namespace information
> into /sbin/bridge-stp therefore don't even try to invoke it except
> for bridge devices in the initial network namespace.
> 
> It is possible for unprivileged users to cause /sbin/bridge-stp to be
> invoked for any network device name which if /sbin/bridge-stp does not
> guard against unreasonable arguments or being invoked twice on the same
> network device could cause problems.
> 
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Just figured that /sbin/bridge-stp is a shell script.
Network interfaces can contain a lot of funny characters,
maybe this is after all a security issue.

Thanks,
//richard

WARNING: multiple messages have this Message-ID (diff)
From: Richard Weinberger <richard@nod.at>
To: "Eric W. Biederman" <ebiederm@xmission.com>,
	David Miller <davem@davemloft.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>,
	bridge@lists.linux-foundation.org,
	Stephen Hemminger <stephen@networkplumber.org>,
	Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH net] bridge: Only call /sbin/bridge-stp for the initial network namespace
Date: Mon, 30 Nov 2015 23:57:29 +0100	[thread overview]
Message-ID: <565CD459.6010402@nod.at> (raw)
In-Reply-To: <87egf7183c.fsf_-_@x220.int.ebiederm.org>

Am 30.11.2015 um 22:38 schrieb Eric W. Biederman:
> 
> There is no defined mechanism to pass network namespace information
> into /sbin/bridge-stp therefore don't even try to invoke it except
> for bridge devices in the initial network namespace.
> 
> It is possible for unprivileged users to cause /sbin/bridge-stp to be
> invoked for any network device name which if /sbin/bridge-stp does not
> guard against unreasonable arguments or being invoked twice on the same
> network device could cause problems.
> 
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Just figured that /sbin/bridge-stp is a shell script.
Network interfaces can contain a lot of funny characters,
maybe this is after all a security issue.

Thanks,
//richard


WARNING: multiple messages have this Message-ID (diff)
From: Richard Weinberger <richard@nod.at>
To: "Eric W. Biederman" <ebiederm@xmission.com>,
	David Miller <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>,
	"kernel-hardening@lists.openwall.com"
	<kernel-hardening@lists.openwall.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	bridge@lists.linux-foundation.org,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net] bridge: Only call /sbin/bridge-stp for the initial network namespace
Date: Mon, 30 Nov 2015 23:57:29 +0100	[thread overview]
Message-ID: <565CD459.6010402@nod.at> (raw)
In-Reply-To: <87egf7183c.fsf_-_@x220.int.ebiederm.org>

Am 30.11.2015 um 22:38 schrieb Eric W. Biederman:
> 
> There is no defined mechanism to pass network namespace information
> into /sbin/bridge-stp therefore don't even try to invoke it except
> for bridge devices in the initial network namespace.
> 
> It is possible for unprivileged users to cause /sbin/bridge-stp to be
> invoked for any network device name which if /sbin/bridge-stp does not
> guard against unreasonable arguments or being invoked twice on the same
> network device could cause problems.
> 
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Just figured that /sbin/bridge-stp is a shell script.
Network interfaces can contain a lot of funny characters,
maybe this is after all a security issue.

Thanks,
//richard

  parent reply	other threads:[~2015-11-30 22:57 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-29 22:43 [Bridge] user controllable usermodehelper in br_stp_if.c Richard Weinberger
2015-11-29 22:43 ` Richard Weinberger
2015-11-29 22:43 ` Richard Weinberger
2015-11-29 22:43 ` [kernel-hardening] " Richard Weinberger
2015-11-30 20:14 ` [Bridge] " Kees Cook
2015-11-30 20:14   ` Kees Cook
2015-11-30 20:14   ` [kernel-hardening] " Kees Cook
2015-11-30 21:38   ` [Bridge] [PATCH net] bridge: Only call /sbin/bridge-stp for the initial network namespace Eric W. Biederman
2015-11-30 21:38     ` Eric W. Biederman
2015-11-30 21:38     ` Eric W. Biederman
2015-11-30 21:38     ` [kernel-hardening] " Eric W. Biederman
2015-11-30 22:12     ` [Bridge] " Stephen Hemminger
2015-11-30 22:12       ` Stephen Hemminger
2015-11-30 22:12       ` Stephen Hemminger
2015-11-30 22:12       ` [kernel-hardening] " Stephen Hemminger
2015-11-30 22:16       ` [Bridge] " Eric W. Biederman
2015-11-30 22:16         ` Eric W. Biederman
2015-11-30 22:16         ` Eric W. Biederman
2015-11-30 22:16         ` [kernel-hardening] " Eric W. Biederman
2015-11-30 22:57     ` Richard Weinberger [this message]
2015-11-30 22:57       ` Richard Weinberger
2015-11-30 22:57       ` Richard Weinberger
2015-11-30 22:57       ` [kernel-hardening] " Richard Weinberger
2015-12-01 14:13     ` [Bridge] " Hannes Frederic Sowa
2015-12-01 14:13       ` Hannes Frederic Sowa
2015-12-01 14:13       ` [kernel-hardening] " Hannes Frederic Sowa
2015-12-03  4:50     ` [Bridge] " David Miller
2015-12-03  4:50       ` David Miller
2015-12-03  4:50       ` David Miller
2015-12-03  4:50       ` [kernel-hardening] " David Miller
2015-12-08 20:56       ` [Bridge] " Kees Cook
2015-12-08 20:56         ` Kees Cook
2015-12-08 20:56         ` [kernel-hardening] " Kees Cook
2015-11-30 23:03   ` [Bridge] user controllable usermodehelper in br_stp_if.c Richard Weinberger
2015-11-30 23:03     ` Richard Weinberger
2015-11-30 23:03     ` Richard Weinberger
2015-11-30 23:03     ` [kernel-hardening] " Richard Weinberger

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