evm: permit only valid security.evm xattrs to be updated
In addition to requiring CAP_SYS_ADMIN permission to modify/delete
security.evm, prohibit invalid security.evm xattrs from changing,
unless in fixmode. This patch prevents inadvertent 'fixing' of
security.evm to reflect offline modifications.
Changelog v7:
- rename boot paramater 'evm_mode' to 'evm'
Reported-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fd248a31..db97ff1 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -48,6 +48,7 @@
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
EFI EFI Partitioning (GPT) is enabled
EIDE EIDE/ATAPI support is enabled.
+ EVM Extended Verification Module
FB The frame buffer device is enabled.
GCOV GCOV profiling is enabled.
HW Appropriate hardware is enabled.
@@ -750,6 +751,11 @@
This option is obsoleted by the "netdev=" option, which
has equivalent usage. See its documentation for details.
+ evm= [EVM]
+ Format: { "fix" }
+ Permit 'security.evm' to be updated regardless of
+ current integrity status.
+
failslab=
fail_page_alloc=
fail_make_request=[KNL]