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From: Oleg Nesterov <oleg@redhat.com>
To: David Howells <dhowells@redhat.com>
Cc: roland@redhat.com, jmorris@namei.org, chrisw@sous-sol.org,
	akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
	linux-security-module@vger.kernel.org, eparis@redhat.com,
	sds@tycho.nsa.gov, Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH 1/2] CRED: Rename cred_exec_mutex to reflect that it's a guard against ptrace
Date: Sat, 9 May 2009 20:59:06 +0200	[thread overview]
Message-ID: <20090509185906.GB10396@redhat.com> (raw)
In-Reply-To: <20090508125522.8488.13637.stgit@warthog.procyon.org.uk>

Sorry for delay,

On 05/08, David Howells wrote:
>
> @@ -185,10 +185,11 @@ int ptrace_attach(struct task_struct *task)
>  	if (same_thread_group(task, current))
>  		goto out;
>
> -	/* Protect exec's credential calculations against our interference;
> -	 * SUID, SGID and LSM creds get determined differently under ptrace.
> +	/* Protect the target's credential calculations against our
> +	 * interference; SUID, SGID and LSM creds get determined differently
> +	 * under ptrace.
>  	 */
> -	retval = mutex_lock_interruptible(&task->cred_exec_mutex);
> +	retval = mutex_lock_interruptible(&task->cred_guard_mutex);
>  	if (retval  < 0)
>  		goto out;
>
> @@ -232,7 +233,7 @@ repeat:
>  bad:
>  	write_unlock_irqrestore(&tasklist_lock, flags);
>  	task_unlock(task);
> -	mutex_unlock(&task->cred_exec_mutex);
> +	mutex_unlock(&task->cred_guard_mutex);

This rename is obviously fine, but conflicts with
ptrace-do-not-use-task_lock-for-attach.patch in -mm tree:

-bad:
-       write_unlock_irqrestore(&tasklist_lock, flags);
-       task_unlock(task);
+unlock_tasklist:
+       write_unlock_irq(&tasklist_lock);
+unlock_creds:
        mutex_unlock(&task->cred_exec_mutex);
 out:
        return retval;


Hmm. Ingo's "rename ptrace_may_access => ptrace_access_check" conflicts
with my patch too.


Andrew, Roland, I guess I should re-send
	
	ptrace-ptrace_attach-check-pf_kthread-exit_state-instead-of-mm.patch
	ptrace-cleanup-check-set-of-pt_ptraced-during-attach.patch
	ptrace-do-not-use-task_lock-for-attach.patch

patches?

Oleg.


  parent reply	other threads:[~2009-05-09 19:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-08 12:55 [PATCH 1/2] CRED: Rename cred_exec_mutex to reflect that it's a guard against ptrace David Howells
2009-05-08 12:55 ` [PATCH 2/2] CRED: Guard the setprocattr security hook " David Howells
2009-05-10 22:37   ` James Morris
2009-05-09 18:59 ` Oleg Nesterov [this message]
2009-05-10 23:29   ` [PATCH 1/2] CRED: Rename cred_exec_mutex to reflect that it's a guard " Roland McGrath
2009-05-11 11:33     ` Ingo Molnar
2009-05-10 22:37 ` James Morris

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