Similar to IMA fix mode, forbid EVM fix mode when secure boot is
enabled.
Reported-and-suggested-by: Mimi Zohar <[email protected]>
Suggested-by: Roberto Sassu <[email protected]>
Signed-off-by: Coiby Xu <[email protected]>
---
security/integrity/evm/evm_main.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/security/integrity/evm/evm_main.c
b/security/integrity/evm/evm_main.c
index 73d500a375cb..00bba266231d 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -72,17 +72,25 @@ static struct xattr_list evm_config_default_xattrnames[] = {
LIST_HEAD(evm_config_xattrnames);
+static char *evm_cmdline __initdata;
+core_param(evm, evm_cmdline, charp, 0);
+
static int evm_fixmode __ro_after_init;
-static int __init evm_set_fixmode(char *str)
+static void __init evm_set_fixmode(void)
{
- if (strncmp(str, "fix", 3) == 0)
- evm_fixmode = 1;
- else
- pr_err("invalid \"%s\" mode", str);
+ if (!evm_cmdline)
+ return;
- return 1;
+ if (strncmp(evm_cmdline, "fix", 3) == 0) {
+ if (arch_integrity_get_secureboot()) {
+ pr_info("Secure boot enabled: ignoring evm=fix");
+ return;
+ }
+ evm_fixmode = 1;
+ } else {
+ pr_err("invalid \"%s\" mode", evm_cmdline);
+ }
}
-__setup("evm=", evm_set_fixmode);
static void __init evm_init_config(void)
{
@@ -1119,6 +1127,8 @@ static int __init init_evm(void)
evm_init_config();
+ evm_set_fixmode();
+
error = integrity_init_keyring(INTEGRITY_KEYRING_EVM);
if (error)
goto error;
--
2.52.0
