[PATCH v3 2/2] ima: check signature enforcement against cmdline param instead of CONFIG
From: Mimi Zohar <hidden>
Date: 2017-10-24 22:55:09
Also in:
linux-integrity, lkml
On Tue, 2017-10-24 at 15:37 -0200, Bruno E. O. Meneguele wrote:
quoted hunk ↗ jump to hunk
When the user requests MODULE_CHECK policy and its kernel is compiled with CONFIG_MODULE_SIG_FORCE not set, all modules would not load, just those loaded in initram time. One option the user would have would be set a kernel cmdline param (module.sig_enforce) to true, but the IMA module check code doesn't rely on this value, it checks just CONFIG_MODULE_SIG_FORCE. This patch solves this problem checking for the exported value of module.sig_enforce cmdline param intead of CONFIG_MODULE_SIG_FORCE, which holds the effective value (CONFIG || param). Signed-off-by: Bruno E. O. Meneguele <redacted> --- security/integrity/ima/ima_main.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index e4ab8ef8016e..d11a7fcc5c8b 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c@@ -356,12 +356,12 @@ void ima_post_path_mknod(struct dentry *dentry) */ int ima_read_file(struct file *file, enum kernel_read_file_id read_id) { + bool sig_enforce = is_module_sig_enforced(); + if (!file && read_id == READING_MODULE) {
The only reason for getting here is that you're using the old module load syscall. ?Is there a reason for not using the new one, which passes the file descriptor? thanks, Mimi
-#ifndef CONFIG_MODULE_SIG_FORCE - if ((ima_appraise & IMA_APPRAISE_MODULES) && + if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES) && (ima_appraise & IMA_APPRAISE_ENFORCE)) return -EACCES; /* INTEGRITY_UNKNOWN */ -#endif return 0; /* We rely on module signature checking */ } return 0;
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