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authorAndrew Perepechko <anserper@ya.ru>2015-12-24 17:09:41 +0100
committerPaul Moore <pmoore@redhat.com>2015-12-24 17:09:41 +0100
commitf9df6458218f4fe8a1c3bf0af89c1fa9eaf0db39 (patch)
treebed3081497a3b7a628fe77f919514e01650d4d8a /security/selinux/selinuxfs.c
parentgfs2: Invalid security labels of inodes when they go invalid (diff)
downloadlinux-f9df6458218f4fe8a1c3bf0af89c1fa9eaf0db39.tar.xz
linux-f9df6458218f4fe8a1c3bf0af89c1fa9eaf0db39.zip
selinux: export validatetrans decisions
Make validatetrans decisions available through selinuxfs. "/validatetrans" is added to selinuxfs for this purpose. This functionality is needed by file system servers implemented in userspace or kernelspace without the VFS layer. Writing "$oldcontext $newcontext $tclass $taskcontext" to /validatetrans is expected to return 0 if the transition is allowed and -EPERM otherwise. Signed-off-by: Andrew Perepechko <anserper@ya.ru> CC: andrew.perepechko@seagate.com Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>
Diffstat (limited to 'security/selinux/selinuxfs.c')
-rw-r--r--security/selinux/selinuxfs.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index c02da25d7b63..0dc407dac3b9 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -116,6 +116,7 @@ enum sel_inos {
SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
SEL_STATUS, /* export current status using mmap() */
SEL_POLICY, /* allow userspace to read the in kernel policy */
+ SEL_VALIDATE_TRANS, /* compute validatetrans decision */
SEL_INO_NEXT, /* The next inode number to use */
};
@@ -653,6 +654,83 @@ static const struct file_operations sel_checkreqprot_ops = {
.llseek = generic_file_llseek,
};
+static ssize_t sel_write_validatetrans(struct file *file,
+ const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char *oldcon = NULL, *newcon = NULL, *taskcon = NULL;
+ char *req = NULL;
+ u32 osid, nsid, tsid;
+ u16 tclass;
+ int rc;
+
+ rc = task_has_security(current, SECURITY__VALIDATE_TRANS);
+ if (rc)
+ goto out;
+
+ rc = -ENOMEM;
+ if (count >= PAGE_SIZE)
+ goto out;
+
+ /* No partial writes. */
+ rc = -EINVAL;
+ if (*ppos != 0)
+ goto out;
+
+ rc = -ENOMEM;
+ req = kzalloc(count + 1, GFP_KERNEL);
+ if (!req)
+ goto out;
+
+ rc = -EFAULT;
+ if (copy_from_user(req, buf, count))
+ goto out;
+
+ rc = -ENOMEM;
+ oldcon = kzalloc(count + 1, GFP_KERNEL);
+ if (!oldcon)
+ goto out;
+
+ newcon = kzalloc(count + 1, GFP_KERNEL);
+ if (!newcon)
+ goto out;
+
+ taskcon = kzalloc(count + 1, GFP_KERNEL);
+ if (!taskcon)
+ goto out;
+
+ rc = -EINVAL;
+ if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4)
+ goto out;
+
+ rc = security_context_str_to_sid(oldcon, &osid, GFP_KERNEL);
+ if (rc)
+ goto out;
+
+ rc = security_context_str_to_sid(newcon, &nsid, GFP_KERNEL);
+ if (rc)
+ goto out;
+
+ rc = security_context_str_to_sid(taskcon, &tsid, GFP_KERNEL);
+ if (rc)
+ goto out;
+
+ rc = security_validate_transition_user(osid, nsid, tsid, tclass);
+ if (!rc)
+ rc = count;
+out:
+ kfree(req);
+ kfree(oldcon);
+ kfree(newcon);
+ kfree(taskcon);
+ return rc;
+}
+
+static const struct file_operations sel_transition_ops = {
+ .write = sel_write_validatetrans,
+ .llseek = generic_file_llseek,
+};
+
/*
* Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
*/
@@ -1759,6 +1837,8 @@ static int sel_fill_super(struct super_block *sb, void *data, int silent)
[SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
[SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
[SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
+ [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops,
+ S_IWUGO},
/* last one */ {""}
};
ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);