Imbed the evm calls evm_inode_setxattr(), evm_inode_post_setxattr(),
evm_inode_removexattr() in the security hooks. evm_inode_setxattr()
protects security.evm xattr. evm_inode_post_setxattr() and
evm_inode_removexattr() updates the hmac associated with an inode.
(Assumes an LSM module protects the setting/removing of xattr.)
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxx>
Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
---
include/linux/evm.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
security/security.c | 16 +++++++++++++-
2 files changed, 68 insertions(+), 2 deletions(-)
create mode 100644 include/linux/evm.h
diff --git a/include/linux/evm.h b/include/linux/evm.h
new file mode 100644
index 0000000..1a30beb
--- /dev/null
+++ b/include/linux/evm.h
@@ -0,0 +1,54 @@
+/*
+ * evm.h
+ *
+ * Copyright (c) 2009 IBM Corporation
+ * Author: Mimi Zohar <zohar@xxxxxxxxxx>
+ */
+
+#ifndef _LINUX_EVM_H
+#define _LINUX_EVM_H
+
+#include <linux/integrity.h>
+
+#ifdef CONFIG_EVM
+extern enum integrity_status evm_verifyxattr(struct dentry *dentry,
+ char *xattr_name,
+ char *xattr_value,
+ size_t xattr_value_len);
+extern int evm_inode_setxattr(struct dentry *dentry, const char *name,
+ const void *value, size_t size);
+extern void evm_inode_post_setxattr(struct dentry *dentry,
+ const char *xattr_name,
+ const void *xattr_value,
+ size_t xattr_value_len);
+extern int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name);
+#else
+static enum integrity_status evm_verifyxattr(struct dentry *dentry,
+ char *xattr_name,
+ char *xattr_value,
+ size_t xattr_value_len)
+{
+ return INTEGRITY_UNKNOWN;
+}
+
+static inline int evm_inode_setxattr(struct dentry *dentry, const char *name,
+ const void *value, size_t size)
+{
+ return 0;
+}
+
+static inline void evm_inode_post_setxattr(struct dentry *dentry,
+ const char *xattr_name,
+ const void *xattr_value,
+ size_t xattr_value_len)
+{
+ return;
+}
+
+static inline int evm_inode_removexattr(struct dentry *dentry,
+ const char *xattr_name)
+{
+ return 0;
+}
+#endif /* CONFIG_EVM_H */
+#endif /* LINUX_EVM_H */
diff --git a/security/security.c b/security/security.c
index 36a0de3..c373c5f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -18,6 +18,7 @@
#include <linux/security.h>
#include <linux/integrity.h>
#include <linux/ima.h>
+#include <linux/evm.h>
/* Boot-time LSM user choice */
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
@@ -548,9 +549,14 @@ int security_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
int security_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
+ int ret;
+
if (unlikely(IS_PRIVATE(dentry->d_inode)))
return 0;
- return security_ops->inode_setxattr(dentry, name, value, size, flags);
+ ret = security_ops->inode_setxattr(dentry, name, value, size, flags);
+ if (ret)
+ return ret;
+ return evm_inode_setxattr(dentry, name, value, size);
}
void security_inode_post_setxattr(struct dentry *dentry, const char *name,
@@ -559,6 +565,7 @@ void security_inode_post_setxattr(struct dentry *dentry, const char *name,
if (unlikely(IS_PRIVATE(dentry->d_inode)))
return;
security_ops->inode_post_setxattr(dentry, name, value, size, flags);
+ evm_inode_post_setxattr(dentry, name, value, size);
}
int security_inode_getxattr(struct dentry *dentry, const char *name)
@@ -577,9 +584,14 @@ int security_inode_listxattr(struct dentry *dentry)
int security_inode_removexattr(struct dentry *dentry, const char *name)
{
+ int ret;
+
if (unlikely(IS_PRIVATE(dentry->d_inode)))
return 0;
- return security_ops->inode_removexattr(dentry, name);
+ ret = security_ops->inode_removexattr(dentry, name);
+ if (ret)
+ return ret;
+ return evm_inode_removexattr(dentry, name);
}
int security_inode_need_killpriv(struct dentry *dentry)
--
1.6.6.1
--
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