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From: Kentaro Takeda <takedakn@nttdata.co.jp>
To: Stephen Smalley <sds@tycho.nsa.gov>,
	James Morris <jmorris@namei.org>,
	Chris Wright <chrisw@sous-sol.org>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Toshiharu Harada <haradats@nttdata.co.jp>,
	Andrew Morton <akpm@linux-foundation.org>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	David Howells <dhowells@redhat.com>
Subject: [TOMOYO #11 (linux-next) 02/11] Add in_execve flag into task_struct.
Date: Mon, 20 Oct 2008 16:34:25 +0900	[thread overview]
Message-ID: <20081020073645.488058369@nttdata.co.jp> (raw)
In-Reply-To: <20081020073423.024299308@nttdata.co.jp>

This patch allows LSM modules to determine whether current process is in an
execve operation or not so that they can behave differently while an execve
operation is in progress.

This allows TOMOYO to dispense with a readability check on a file to be
executed under the process's current credentials, and to do it instead under
the proposed credentials.

This is required with the new COW credentials because TOMOYO is no longer
allowed to mark the state temporarily in the security struct attached to the
task_struct.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David Howells <dhowells@redhat.com>
---
 fs/compat.c           |    3 +++
 fs/exec.c             |    3 +++
 include/linux/sched.h |    2 ++
 3 files changed, 8 insertions(+)

--- linux-next.orig/fs/compat.c
+++ linux-next/fs/compat.c
@@ -1396,6 +1396,7 @@ int compat_do_execve(char * filename,
 	retval = mutex_lock_interruptible(&current->cred_exec_mutex);
 	if (retval < 0)
 		goto out_free;
+	current->in_execve = 1;
 
 	retval = -ENOMEM;
 	bprm->cred = prepare_exec_creds();
@@ -1448,6 +1449,7 @@ int compat_do_execve(char * filename,
 		goto out;
 
 	/* execve succeeded */
+	current->in_execve = 0;
 	mutex_unlock(&current->cred_exec_mutex);
 	acct_update_integrals(current);
 	free_bprm(bprm);
@@ -1464,6 +1466,7 @@ out_file:
 	}
 
 out_unlock:
+	current->in_execve = 0;
 	mutex_unlock(&current->cred_exec_mutex);
 
 out_free:
--- linux-next.orig/fs/exec.c
+++ linux-next/fs/exec.c
@@ -1303,6 +1303,7 @@ int do_execve(char * filename,
 	retval = mutex_lock_interruptible(&current->cred_exec_mutex);
 	if (retval < 0)
 		goto out_free;
+	current->in_execve = 1;
 
 	retval = -ENOMEM;
 	bprm->cred = prepare_exec_creds();
@@ -1356,6 +1357,7 @@ int do_execve(char * filename,
 		goto out;
 
 	/* execve succeeded */
+	current->in_execve = 0;
 	mutex_unlock(&current->cred_exec_mutex);
 	acct_update_integrals(current);
 	free_bprm(bprm);
@@ -1374,6 +1376,7 @@ out_file:
 	}
 
 out_unlock:
+	current->in_execve = 0;
 	mutex_unlock(&current->cred_exec_mutex);
 
 out_free:
--- linux-next.orig/include/linux/sched.h
+++ linux-next/include/linux/sched.h
@@ -1089,6 +1089,8 @@ struct task_struct {
 	/* ??? */
 	unsigned int personality;
 	unsigned did_exec:1;
+	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
+				 * execve */
 	pid_t pid;
 	pid_t tgid;
 

--


  parent reply	other threads:[~2008-10-20  7:37 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-20  7:34 [TOMOYO #11 (linux-next) 00/11] TOMOYO Linux Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 01/11] Introduce new LSM hooks where vfsmount is available Kentaro Takeda
2008-10-20 12:27   ` Shaya Potter
2008-10-20 19:34     ` crispin
2008-10-20 21:23       ` Shaya Potter
2008-10-23 17:57         ` Shaya Potter
2008-10-20 16:44   ` Miklos Szeredi
2008-10-21  5:09     ` Kentaro Takeda
2008-10-20  7:34 ` Kentaro Takeda [this message]
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 03/11] Singly linked list implementation Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 04/11] Introduce d_realpath() Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 05/11] Memory and pathname management functions Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 06/11] Common functions for TOMOYO Linux Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 07/11] File operation restriction part Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 08/11] Domain transition handler Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 09/11] LSM adapter functions Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 10/11] Kconfig and Makefile Kentaro Takeda
2008-10-20  7:34 ` [TOMOYO #11 (linux-next) 11/11] MAINTAINERS info Kentaro Takeda
2008-10-27  2:18 ` [TOMOYO #11 (linux-next) 00/11] TOMOYO Linux Kentaro Takeda
2008-10-29 19:18   ` Serge E. Hallyn
2008-10-30  5:27     ` Toshiharu Harada

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