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From: ebiederm@xmission.com (Eric W. Biederman)
To: Andrew Morton <akpm@osdl.org>
Cc: Ingo Molnar <mingo@elte.hu>,
	tglx@linutronix.de, linux-kernel@vger.kernel.org,
	selinux@tycho.nsa.gov, jmorris@namei.org,
	Stephen Smalley <sds@tycho.nsa.gov>
Subject: [PATCH 2/2] sysctl: Restore the selinux path based label lookup for sysctls.
Date: Tue, 06 Feb 2007 14:21:54 -0700	[thread overview]
Message-ID: <m13b5jrngt.fsf_-_@ebiederm.dsl.xmission.com> (raw)
In-Reply-To: <m17iuvrnpk.fsf_-_@ebiederm.dsl.xmission.com> (Eric W. Biederman's message of "Tue, 06 Feb 2007 14:16:39 -0700")


This time instead of generating the generating the paths from proc_dir_entries
generate the labels from the names in the sysctl ctl_tables themselves.  This
removes an unnecessary layer of indirection, allows this to work even when
procfs support is not compiled into the kernel, and especially allows it
to work now that ctl_tables no longer have a proc_dir_entry field.

I continue passing "proc" into genfs sid although that is complete nonsense
to allow existing selinux policies to work without modification.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 security/selinux/hooks.c |   43 +++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3a36057..c17a8dd 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1424,6 +1424,41 @@ static int selinux_capable(struct task_struct *tsk, int cap)
 	return task_has_capability(tsk,cap);
 }
 
+static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
+{
+	int buflen, rc;
+	char *buffer, *path, *end;
+
+	rc = -ENOMEM;
+	buffer = (char*)__get_free_page(GFP_KERNEL);
+	if (!buffer)
+		goto out;
+
+	buflen = PAGE_SIZE;
+	end = buffer+buflen;
+	*--end = '\0';
+	buflen--;
+	path = end-1;
+	*path = '/';
+	while (table) {
+		const char *name = table->procname;
+		size_t namelen = strlen(name);
+		buflen -= namelen + 1;
+		if (buflen < 0)
+			goto out_free;
+		end -= namelen;
+		memcpy(end, name, namelen);
+		*--end = '/';
+		path = end;
+		table = table->parent;
+	}
+	rc = security_genfs_sid("proc", path, tclass, sid);
+out_free:
+	free_page((unsigned long)buffer);
+out:
+	return rc;
+}
+
 static int selinux_sysctl(ctl_table *table, int op)
 {
 	int error = 0;
@@ -1438,8 +1473,12 @@ static int selinux_sysctl(ctl_table *table, int op)
 
 	tsec = current->security;
 
-	/* Use the well-defined sysctl SID. */
-	tsid = SECINITSID_SYSCTL;
+	rc = selinux_sysctl_get_sid(table, (op == 0001) ?
+				    SECCLASS_DIR : SECCLASS_FILE, &tsid);
+	if (rc) {
+		/* Default to the well-defined sysctl SID. */
+		tsid = SECINITSID_SYSCTL;
+	}
 
 	/* The op values are "defined" in sysctl.c, thereby creating
 	 * a bad coupling between this module and sysctl.c */
-- 
1.4.4.1.g278f


  reply	other threads:[~2007-02-06 21:22 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <200701280106.l0S16CG3019873@shell0.pdx.osdl.net>
     [not found] ` <20070127172410.2b041952.akpm@osdl.org>
     [not found]   ` <1169972718.17469.164.camel@localhost.localdomain>
     [not found]     ` <20070128003549.2ca38dc8.akpm@osdl.org>
     [not found]       ` <20070128093358.GA2071@elte.hu>
     [not found]         ` <20070128095712.GA6485@elte.hu>
     [not found]           ` <20070128100627.GA8416@elte.hu>
     [not found]             ` <20070128104548.a835d859.akpm@osdl.org>
2007-01-28 19:21               ` [PATCH] sysctl selinux: Don't look at table->de Eric W. Biederman
2007-01-29 13:04                 ` Stephen Smalley
2007-01-29 15:23                   ` James Morris
2007-01-29 17:55                     ` Eric W. Biederman
2007-01-29 19:26                       ` Stephen Smalley
2007-01-29 17:43                   ` Eric W. Biederman
2007-01-29 18:43                     ` Stephen Smalley
2007-01-29 19:08                       ` Casey Schaufler
2007-01-29 20:07                         ` Stephen Smalley
2007-01-30 10:25                         ` Christoph Hellwig
2007-01-30 17:19                           ` Casey Schaufler
2007-01-29 19:16                       ` Eric W. Biederman
2007-01-29 23:28                       ` Russell Coker
2007-02-06 21:16                   ` [PATCH 1/2] sysctl: Add a parent entry to ctl_table and set the parent entry Eric W. Biederman
2007-02-06 21:21                     ` Eric W. Biederman [this message]
2007-02-07 18:24                       ` [PATCH 2/2] sysctl: Restore the selinux path based label lookup for sysctls Stephen Smalley
2007-02-07 21:12                         ` Stephen Smalley
2007-02-07 21:54                           ` Stephen Smalley
2007-02-07 22:21                             ` Eric W. Biederman
2007-02-08 15:07                               ` Stephen Smalley
2007-02-08  1:57                           ` Eric W. Biederman
2007-02-08 15:01                             ` Stephen Smalley
2007-02-08 17:53                               ` Eric W. Biederman
2007-02-08 18:13                                 ` Stephen Smalley
2007-02-08 22:17                                   ` Eric W. Biederman
2007-02-08 22:51                                     ` [PATCH 0/5] sysctl cleanup selinux fixes Eric W. Biederman
2007-02-08 22:53                                       ` [PATCH 1/5] sysctl: Remove declaration of nonexistent sysctl_init() Eric W. Biederman
2007-02-08 22:54                                         ` [PATCH 2/5] sysctl: Set the parent field in the root sysctl table Eric W. Biederman
2007-02-08 22:55                                           ` [PATCH 3/5] sysctl: Fix the selinux_sysctl_get_sid Eric W. Biederman
2007-02-08 23:02                                             ` [PATCH 4/5] selinux: Enhance selinux to always ignore private inodes Eric W. Biederman
2007-02-08 23:04                                               ` [PATCH 5/5] sysctl: Hide the sysctl proc inodes from selinux Eric W. Biederman
2007-02-09 12:26                                               ` [PATCH 4/5] selinux: Enhance selinux to always ignore private inodes Stephen Smalley
2007-02-09 12:24                                             ` [PATCH 3/5] sysctl: Fix the selinux_sysctl_get_sid Stephen Smalley
2007-02-09 11:05                                       ` [PATCH 0/5] sysctl cleanup selinux fixes Andrew Morton
2007-02-09 18:09                                         ` Eric W. Biederman

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