* [PATCH] ima: force signature verification when CONFIG_KEXEC_SIG is configured
@ 2022-07-12 9:33 Coiby Xu
2022-07-12 11:40 ` Mimi Zohar
2022-07-13 7:21 ` [PATCH v2] " Coiby Xu
0 siblings, 2 replies; 4+ messages in thread
From: Coiby Xu @ 2022-07-12 9:33 UTC (permalink / raw)
To: linux-integrity
Cc: kexec, Baoquan He, Mimi Zohar, Eric Biederman, Dmitry Kasatkin,
James Morris, Serge E. Hallyn, David Howells, Jiri Bohac,
Matthew Garrett, open list, open list:SECURITY SUBSYSTEM
Currently, an unsigned kernel could be kexec'ed when IMA arch specific
policy is configured unless lockdown is enabled. Enforce kernel
signature verification check in the kexec_file_load syscall when IMA
arch specific policy is configured.
Fixes: 99d5cadfde2b ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE")
Reported-by: Mimi Zohar <zohar@linux.ibm.com>
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
include/linux/kexec.h | 3 +++
kernel/kexec_file.c | 11 ++++++++++-
security/integrity/ima/ima_efi.c | 3 +++
3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index ce6536f1d269..4b8e8d5bcea9 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -134,6 +134,9 @@ typedef int (kexec_cleanup_t)(void *loader_data);
#ifdef CONFIG_KEXEC_SIG
typedef int (kexec_verify_sig_t)(const char *kernel_buf,
unsigned long kernel_len);
+void set_kexec_sig_enforced(void);
+#else
+static inline void set_kexec_sig_enforced(void) {}
#endif
struct kexec_file_ops {
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 145321a5e798..f9261c07b048 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -29,6 +29,15 @@
#include <linux/vmalloc.h>
#include "kexec_internal.h"
+#ifdef CONFIG_KEXEC_SIG
+static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE);
+
+void set_kexec_sig_enforced(void)
+{
+ sig_enforce = true;
+}
+#endif
+
static int kexec_calculate_store_digests(struct kimage *image);
/*
@@ -159,7 +168,7 @@ kimage_validate_signature(struct kimage *image)
image->kernel_buf_len);
if (ret) {
- if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) {
+ if (sig_enforce) {
pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
return ret;
}
diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c
index 71786d01946f..ae3fe4cb8d86 100644
--- a/security/integrity/ima/ima_efi.c
+++ b/security/integrity/ima/ima_efi.c
@@ -3,6 +3,7 @@
* Copyright (C) 2018 IBM Corporation
*/
#include <linux/efi.h>
+#include <linux/kexec.h>
#include <linux/module.h>
#include <linux/ima.h>
#include <asm/efi.h>
@@ -67,6 +68,8 @@ const char * const *arch_get_ima_policy(void)
if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) {
if (IS_ENABLED(CONFIG_MODULE_SIG))
set_module_sig_enforced();
+ if (IS_ENABLED(CONFIG_KEXEC_SIG))
+ set_kexec_sig_enforced();
return sb_arch_rules;
}
return NULL;
--
2.35.3
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] ima: force signature verification when CONFIG_KEXEC_SIG is configured
2022-07-12 9:33 [PATCH] ima: force signature verification when CONFIG_KEXEC_SIG is configured Coiby Xu
@ 2022-07-12 11:40 ` Mimi Zohar
2022-07-13 7:21 ` [PATCH v2] " Coiby Xu
1 sibling, 0 replies; 4+ messages in thread
From: Mimi Zohar @ 2022-07-12 11:40 UTC (permalink / raw)
To: Coiby Xu, linux-integrity
Cc: kexec, Baoquan He, Eric Biederman, Dmitry Kasatkin, James Morris,
Serge E. Hallyn, David Howells, Jiri Bohac, Matthew Garrett,
open list, open list:SECURITY SUBSYSTEM
On Tue, 2022-07-12 at 17:33 +0800, Coiby Xu wrote:
> Currently, an unsigned kernel could be kexec'ed when IMA arch specific
> policy is configured unless lockdown is enabled. Enforce kernel
> signature verification check in the kexec_file_load syscall when IMA
> arch specific policy is configured.
>
> Fixes: 99d5cadfde2b ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE")
> Reported-by: Mimi Zohar <zohar@linux.ibm.com>
> Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
> Signed-off-by: Coiby Xu <coxu@redhat.com>
Thanks, Coiby. This patch is now queued in next-integrity/next-
integrity-testing.
Mimi
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2] ima: force signature verification when CONFIG_KEXEC_SIG is configured
2022-07-12 9:33 [PATCH] ima: force signature verification when CONFIG_KEXEC_SIG is configured Coiby Xu
2022-07-12 11:40 ` Mimi Zohar
@ 2022-07-13 7:21 ` Coiby Xu
2022-07-13 14:23 ` Mimi Zohar
1 sibling, 1 reply; 4+ messages in thread
From: Coiby Xu @ 2022-07-13 7:21 UTC (permalink / raw)
To: linux-integrity
Cc: kexec, Baoquan He, Mimi Zohar, Eric Biederman, Dmitry Kasatkin,
James Morris, Serge E. Hallyn, Jiri Bohac, David Howells,
Matthew Garrett, open list, open list:SECURITY SUBSYSTEM
Currently, an unsigned kernel could be kexec'ed when IMA arch specific
policy is configured unless lockdown is enabled. Enforce kernel
signature verification check in the kexec_file_load syscall when IMA
arch specific policy is configured.
Fixes: 99d5cadfde2b ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE")
Reported-by: Mimi Zohar <zohar@linux.ibm.com>
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
v2
- don't include linux/kexec.h since it's already been included in
linux/ima.h
- fix build errors when KEXEC_FILE/KEXEC_CORE is disable as caught by
kernel test robot <lkp@intel.com>
---
include/linux/kexec.h | 6 ++++++
kernel/kexec_file.c | 11 ++++++++++-
security/integrity/ima/ima_efi.c | 2 ++
3 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index ce6536f1d269..475683cd67f1 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -452,6 +452,12 @@ static inline int kexec_crash_loaded(void) { return 0; }
#define kexec_in_progress false
#endif /* CONFIG_KEXEC_CORE */
+#ifdef CONFIG_KEXEC_SIG
+void set_kexec_sig_enforced(void);
+#else
+static inline void set_kexec_sig_enforced(void) {}
+#endif
+
#endif /* !defined(__ASSEBMLY__) */
#endif /* LINUX_KEXEC_H */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 145321a5e798..f9261c07b048 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -29,6 +29,15 @@
#include <linux/vmalloc.h>
#include "kexec_internal.h"
+#ifdef CONFIG_KEXEC_SIG
+static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE);
+
+void set_kexec_sig_enforced(void)
+{
+ sig_enforce = true;
+}
+#endif
+
static int kexec_calculate_store_digests(struct kimage *image);
/*
@@ -159,7 +168,7 @@ kimage_validate_signature(struct kimage *image)
image->kernel_buf_len);
if (ret) {
- if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) {
+ if (sig_enforce) {
pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
return ret;
}
diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c
index 71786d01946f..9db66fe310d4 100644
--- a/security/integrity/ima/ima_efi.c
+++ b/security/integrity/ima/ima_efi.c
@@ -67,6 +67,8 @@ const char * const *arch_get_ima_policy(void)
if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) {
if (IS_ENABLED(CONFIG_MODULE_SIG))
set_module_sig_enforced();
+ if (IS_ENABLED(CONFIG_KEXEC_SIG))
+ set_kexec_sig_enforced();
return sb_arch_rules;
}
return NULL;
--
2.35.3
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] ima: force signature verification when CONFIG_KEXEC_SIG is configured
2022-07-13 7:21 ` [PATCH v2] " Coiby Xu
@ 2022-07-13 14:23 ` Mimi Zohar
0 siblings, 0 replies; 4+ messages in thread
From: Mimi Zohar @ 2022-07-13 14:23 UTC (permalink / raw)
To: Coiby Xu, linux-integrity
Cc: kexec, Baoquan He, Eric Biederman, Dmitry Kasatkin, James Morris,
Serge E. Hallyn, Jiri Bohac, David Howells, Matthew Garrett,
open list, open list:SECURITY SUBSYSTEM
On Wed, 2022-07-13 at 15:21 +0800, Coiby Xu wrote:
> Currently, an unsigned kernel could be kexec'ed when IMA arch specific
> policy is configured unless lockdown is enabled. Enforce kernel
> signature verification check in the kexec_file_load syscall when IMA
> arch specific policy is configured.
>
> Fixes: 99d5cadfde2b ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE")
> Reported-by: Mimi Zohar <zohar@linux.ibm.com>
> Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
> Signed-off-by: Coiby Xu <coxu@redhat.com>
> ---
> v2
> - don't include linux/kexec.h since it's already been included in
> linux/ima.h
> - fix build errors when KEXEC_FILE/KEXEC_CORE is disable as caught by
> kernel test robot <lkp@intel.com>
Thanks, Coiby. This version of the patch is now queued in next-
integrity/next-
integrity-testing.
Mimi
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-07-12 9:33 [PATCH] ima: force signature verification when CONFIG_KEXEC_SIG is configured Coiby Xu
2022-07-12 11:40 ` Mimi Zohar
2022-07-13 7:21 ` [PATCH v2] " Coiby Xu
2022-07-13 14:23 ` Mimi Zohar
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