This patch introduces two new hooks. One to get all relevant information from
an LSM about an inode an the second given that context to set it on the
inode. The setcontext call takes a flag to indicate if it should set the incore
representation, the ondisk representation or both. This hook is for use in the
labeled NFS code and addresses concerns of how to set security on an inode in a
multi-xattr LSM.
Signed-off-by: David P. Quigley <dpquigl@xxxxxxxxxxxxx>
---
include/linux/security.h | 18 ++++++++++++++++++
security/dummy.c | 12 ++++++++++++
security/security.c | 12 ++++++++++++
security/selinux/hooks.c | 31 ++++++++++++++++++++++++++++++-
4 files changed, 72 insertions(+), 1 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index fe52cde..bb71ac9 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -112,6 +112,10 @@ struct request_sock;
#define LSM_UNSAFE_PTRACE 2
#define LSM_UNSAFE_PTRACE_CAP 4
+/* Flags for setsecctx */
+#define LSM_SETCORE 1
+#define LSM_SETDISK 2
+
#ifdef CONFIG_SECURITY
/**
@@ -1395,6 +1399,9 @@ struct security_operations {
int (*secctx_to_secid)(char *secdata, u32 seclen, u32 *secid);
void (*release_secctx)(char *secdata, u32 seclen);
+ int (*inode_setsecctx)(struct dentry *dentry, void *ctx, u32 ctxlen, int flags);
+ int (*inode_getsecctx)(struct dentry *dentry, void **ctx, u32 *ctxlen);
+
#ifdef CONFIG_SECURITY_NETWORK
int (*unix_stream_connect) (struct socket * sock,
struct socket * other, struct sock * newsk);
@@ -1634,6 +1641,8 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
int security_secctx_to_secid(char *secdata, u32 seclen, u32 *secid);
void security_release_secctx(char *secdata, u32 seclen);
+int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen, int flags);
+int security_inode_getsecctx(struct dentry *dentry, void **ctx, u32 *ctxlen);
#else /* CONFIG_SECURITY */
/*
@@ -2316,6 +2325,15 @@ static inline int security_secctx_to_secid(char *secdata,
static inline void security_release_secctx(char *secdata, u32 seclen)
{
}
+
+static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen, int flags)
+{
+ return -EOPNOTSUPP;
+}
+static inline int security_inode_getsecctx(struct dentry *dentry, void **ctx, u32 *ctxlen)
+{
+ return -EOPNOTSUPP;
+}
#endif /* CONFIG_SECURITY */
#ifdef CONFIG_SECURITY_NETWORK
diff --git a/security/dummy.c b/security/dummy.c
index 649326b..774e243 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -960,6 +960,16 @@ static void dummy_release_secctx(char *secdata, u32 seclen)
{
}
+static int dummy_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen, int flags)
+{
+ return -EOPNOTSUPP;
+}
+
+static int dummy_inode_getsecctx(struct dentry *dentry, void **ctx, u32 *ctxlen)
+{
+ return -EOPNOTSUPP;
+}
+
#ifdef CONFIG_KEYS
static inline int dummy_key_alloc(struct key *key, struct task_struct *ctx,
unsigned long flags)
@@ -1118,6 +1128,8 @@ void security_fixup_ops (struct security_operations *ops)
set_to_dummy_if_null(ops, secid_to_secctx);
set_to_dummy_if_null(ops, secctx_to_secid);
set_to_dummy_if_null(ops, release_secctx);
+ set_to_dummy_if_null(ops, inode_setsecctx);
+ set_to_dummy_if_null(ops, inode_getsecctx);
#ifdef CONFIG_SECURITY_NETWORK
set_to_dummy_if_null(ops, unix_stream_connect);
set_to_dummy_if_null(ops, unix_may_send);
diff --git a/security/security.c b/security/security.c
index d15e56c..84db95a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -845,6 +845,18 @@ void security_release_secctx(char *secdata, u32 seclen)
}
EXPORT_SYMBOL(security_release_secctx);
+int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen, int flags)
+{
+ return security_ops->inode_setsecctx(dentry, ctx, ctxlen, flags);
+}
+EXPORT_SYMBOL(security_inode_setsecctx);
+
+int security_inode_getsecctx(struct dentry *dentry, void **ctx, u32 *ctxlen)
+{
+ return security_ops->inode_getsecctx(dentry, ctx, ctxlen);
+}
+EXPORT_SYMBOL(security_inode_getsecctx);
+
#ifdef CONFIG_SECURITY_NETWORK
int security_unix_stream_connect(struct socket *sock, struct socket *other,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 75c2e99..47e8fb0 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -75,6 +75,7 @@
#include <linux/string.h>
#include <linux/selinux.h>
#include <linux/mutex.h>
+#include <linux/fsnotify.h>
#include "avc.h"
#include "objsec.h"
@@ -5163,6 +5164,33 @@ static void selinux_release_secctx(char *secdata, u32 seclen)
kfree(secdata);
}
+/*
+ * This hook requires that the inode i_mutex be locked
+ */
+static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen, int flags)
+{
+ struct inode *inode = dentry->d_inode;
+ int rc = 0;
+
+ if (flags & LSM_SETCORE) {
+ rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX,
+ ctx, ctxlen, 0);
+ if(rc)
+ return rc;
+ }
+ if (flags & LSM_SETDISK)
+ rc = do_setxattr(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
+
+ return rc;
+}
+static int selinux_inode_getsecctx(struct dentry *dentry, void **ctx, u32 *ctxlen)
+{
+ struct inode *inode = dentry->d_inode;
+
+ *ctxlen = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
+ ctx, true);
+ return *ctxlen;
+}
#ifdef CONFIG_KEYS
static int selinux_key_alloc(struct key *k, struct task_struct *tsk,
@@ -5351,7 +5379,8 @@ static struct security_operations selinux_ops = {
.secid_to_secctx = selinux_secid_to_secctx,
.secctx_to_secid = selinux_secctx_to_secid,
.release_secctx = selinux_release_secctx,
-
+ .inode_setsecctx = selinux_inode_setsecctx,
+ .inode_getsecctx = selinux_inode_getsecctx,
.unix_stream_connect = selinux_socket_unix_stream_connect,
.unix_may_send = selinux_socket_unix_may_send,
--
1.5.4.1
--
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