linux-kernel - [PATCH 06/15] security: imbed evm calls in security hooks

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1277403031-3080-7-git-send-email-zohar@linux.vnet.ibm.com>
Date:	Thu, 24 Jun 2010 14:10:22 -0400
From:	Mimi Zohar <zohar@...ux.vnet.ibm.com>
To:	linux-kernel@...r.kernel.org
Cc:	Mimi Zohar <zohar@...ux.vnet.ibm.com>,
	linux-security-module@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, James Morris <jmorris@...ei.org>,
	David Safford <safford@...son.ibm.com>,
	Dave Hansen <dave@...ux.vnet.ibm.com>,
	Mimi Zohar <zohar@...ibm.com>
Subject: [PATCH 06/15] security: imbed evm calls in security hooks

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@...ibm.com>
Acked-by: Serge Hallyn <serue@...ibm.com>
---
 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@...ibm.com>
+ */
+
+#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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/