evm: provide option to protect additional SMACK xattrs

Newer versions of SMACK introduced following security xattrs:
SMACK64EXEC, SMACK64TRANSMUTE and SMACK64MMAP.

To protect these xattrs, this patch includes them in the HMAC
calculation.  However, for backwards compatibility with existing
labeled filesystems, including these xattrs needs to be
configurable.

Changelog:
- Add SMACK dependency on new option (Mimi)

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig
index 0df4f7a..d606f3d 100644 (file)
--- a/security/integrity/evm/Kconfig
+++ b/security/integrity/evm/Kconfig
@@ -30,6 +30,23 @@ config EVM_ATTR_FSUUID
          additional info to the calculation, requires existing EVM
          labeled file systems to be relabeled.
 
+config EVM_EXTRA_SMACK_XATTRS
+       bool "Additional SMACK xattrs"
+       depends on EVM && SECURITY_SMACK
+       default n
+       help
+         Include additional SMACK xattrs for HMAC calculation.
+
+         In addition to the original security xattrs (eg. security.selinux,
+         security.SMACK64, security.capability, and security.ima) included
+         in the HMAC calculation, enabling this option includes newly defined
+         Smack xattrs: security.SMACK64EXEC, security.SMACK64TRANSMUTE and
+         security.SMACK64MMAP.
+
+         WARNING: changing the HMAC calculation method or adding
+         additional info to the calculation, requires existing EVM
+         labeled file systems to be relabeled.
+
 endmenu
 
 endif

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 1dc0919..73baf71 100644 (file)
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -40,6 +40,11 @@ char *evm_config_xattrnames[] = {
 #endif
 #ifdef CONFIG_SECURITY_SMACK
        XATTR_NAME_SMACK,
+#ifdef CONFIG_EVM_EXTRA_SMACK_XATTRS
+       XATTR_NAME_SMACKEXEC,
+       XATTR_NAME_SMACKTRANSMUTE,
+       XATTR_NAME_SMACKMMAP,
+#endif
 #endif
 #ifdef CONFIG_IMA_APPRAISE
        XATTR_NAME_IMA,