[v2,04/10] ima: define "fs_unsafe" builtin policy

Commit Message

Mimi Zohar June 21, 2017, 6:18 p.m. UTC

Permit normally denied access/execute permission for files in policy
on IMA unsupported filesystems.  This patch defines "fs_unsafe", a
builtin policy.

Mimi Zohar <[e-mail]>
---
 Documentation/admin-guide/kernel-parameters.txt | 8 +++++++-
 security/integrity/ima/ima_policy.c             | 2 ++
 2 files changed, 9 insertions(+), 1 deletion(-)

Patch

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e438a1fca554..0aed01aabc16 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1478,7 +1478,7 @@ 
 
 	ima_policy=	[IMA]
 			The builtin policies to load during IMA setup.
-			Format: "tcb | appraise_tcb | secure_boot"
+			Format: "tcb | appraise_tcb | secure_boot | fs_unsafe"
 
 			The "tcb" policy measures all programs exec'd, files
 			mmap'd for exec, and all files opened with the read
@@ -1493,6 +1493,12 @@ 
 			of files (eg. kexec kernel image, kernel modules,
 			firmware, policy, etc) based on file signatures.
 
+			The "fs_unsafe" policy permits normally denied
+			access/execute permission for files in policy on IMA
+			unsupported filesystems.  Note this option, as the
+			name implies, is not safe and not recommended for
+			any environments other than testing.
+
 	ima_tcb		[IMA] Deprecated.  Use ima_policy= instead.
 			Load a policy which meets the needs of the Trusted
 			Computing Base.  This means IMA will measure all
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index cb92c9c04e80..4ff5640522c7 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -200,6 +200,8 @@  static int __init policy_setup(char *str)
 			ima_use_appraise_tcb = 1;
 		else if (strcmp(p, "secure_boot") == 0)
 			ima_use_secure_boot = 1;
+		else if (strcmp(p, "fs_unsafe") == 0)
+			set_failsafe(0);
 	}
 
 	return 1;