From: Ondrej Mosnacek <omosnace@redhat.com>
To: selinux@vger.kernel.org, Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>,
linux-security-module@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Casey Schaufler <casey@schaufler-ca.com>,
"Serge E . Hallyn" <serge@hallyn.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
James Morris <jmorris@namei.org>,
linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org,
Ondrej Mosnacek <omosnace@redhat.com>
Subject: [PATCH v7 6/7] selinux: implement the kernfs_init_security hook
Date: Fri, 22 Feb 2019 15:57:17 +0100 [thread overview]
Message-ID: <20190222145718.5740-7-omosnace@redhat.com> (raw)
In-Reply-To: <20190222145718.5740-1-omosnace@redhat.com>
The hook applies the same logic as selinux_determine_inode_label(), with
the exception of the super_block handling, which will be enforced on the
actual inodes later by other hooks.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
---
security/selinux/hooks.c | 66 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 0f62757b6634..42b576d82d7f 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -88,6 +88,8 @@
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/bpf.h>
+#include <linux/kernfs.h>
+#include <linux/stringhash.h> /* for hashlen_string() */
#include <uapi/linux/mount.h>
#include "avc.h"
@@ -3350,6 +3352,68 @@ static int selinux_inode_copy_up_xattr(const char *name)
return -EOPNOTSUPP;
}
+/* kernfs node operations */
+
+int selinux_kernfs_init_security(struct kernfs_node *kn_dir,
+ struct kernfs_node *kn)
+{
+ const struct task_security_struct *tsec = current_security();
+ u32 parent_sid, newsid, clen;
+ int rc;
+ char *context;
+
+ rc = kernfs_security_xattr_get(kn_dir, XATTR_SELINUX_SUFFIX, NULL, 0);
+ if (rc == -ENODATA)
+ return 0;
+ else if (rc < 0)
+ return rc;
+
+ clen = (u32)rc;
+ context = kmalloc(clen, GFP_KERNEL);
+ if (!context)
+ return -ENOMEM;
+
+ rc = kernfs_security_xattr_get(kn_dir, XATTR_SELINUX_SUFFIX, context,
+ clen);
+ if (rc < 0) {
+ kfree(context);
+ return rc;
+ }
+
+ rc = security_context_to_sid(&selinux_state, context, clen, &parent_sid,
+ GFP_KERNEL);
+ kfree(context);
+ if (rc)
+ return rc;
+
+ if (tsec->create_sid) {
+ newsid = tsec->create_sid;
+ } else {
+ u16 secclass = inode_mode_to_security_class(kn->mode);
+ struct qstr q;
+
+ q.name = kn->name;
+ q.hash_len = hashlen_string(kn_dir, kn->name);
+
+ rc = security_transition_sid(&selinux_state, tsec->sid,
+ parent_sid, secclass, &q,
+ &newsid);
+ if (rc)
+ return rc;
+ }
+
+ rc = security_sid_to_context_force(&selinux_state, newsid,
+ &context, &clen);
+ if (rc)
+ return rc;
+
+ rc = kernfs_security_xattr_set(kn, XATTR_SELINUX_SUFFIX, context, clen,
+ XATTR_CREATE);
+ kfree(context);
+ return rc;
+}
+
+
/* file security operations */
static int selinux_revalidate_file_permission(struct file *file, int mask)
@@ -6796,6 +6860,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
+ LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
+
LSM_HOOK_INIT(file_permission, selinux_file_permission),
LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
LSM_HOOK_INIT(file_free_security, selinux_file_free_security),
--
2.20.1
next prev parent reply other threads:[~2019-02-22 14:58 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-22 14:57 [PATCH v7 0/7] Allow initializing the kernfs node's secctx based on its parent Ondrej Mosnacek
2019-02-22 14:57 ` [PATCH v7 1/7] kernfs: clean up struct kernfs_iattrs Ondrej Mosnacek
2019-02-22 14:57 ` [PATCH v7 2/7] kernfs: do not alloc iattrs in kernfs_xattr_get Ondrej Mosnacek
2019-02-22 14:57 ` [PATCH v7 3/7] selinux: try security xattr after genfs for kernfs filesystems Ondrej Mosnacek
2019-02-22 15:40 ` Stephen Smalley
2019-02-22 14:57 ` [PATCH v7 4/7] kernfs: use simple_xattrs for security attributes Ondrej Mosnacek
2019-02-22 14:57 ` [PATCH v7 5/7] LSM: add new hook for kernfs node initialization Ondrej Mosnacek
2019-02-22 14:57 ` Ondrej Mosnacek [this message]
2019-02-22 14:57 ` [PATCH v7 7/7] kernfs: initialize security of newly created nodes Ondrej Mosnacek
2019-03-06 15:54 ` [PATCH v7 0/7] Allow initializing the kernfs node's secctx based on its parent Ondrej Mosnacek
2019-03-06 16:20 ` Paul Moore
2019-03-07 9:00 ` Ondrej Mosnacek
2019-03-06 18:04 ` Casey Schaufler
2019-03-07 9:01 ` Ondrej Mosnacek
2019-03-21 2:14 ` Paul Moore
2019-03-21 8:56 ` Ondrej Mosnacek
2019-03-21 21:21 ` Paul Moore
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