The patch titled
Subject: ima: on soft reboot, save the measurement list
has been added to the -mm tree. Its filename is
ima-on-soft-reboot-save-the-measurement-list.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ima-on-soft-reboot-save-the-measurement-list.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ima-on-soft-reboot-save-the-measurement-list.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxxxxxxx>
Subject: ima: on soft reboot, save the measurement list
This patch uses the kexec buffer passing mechanism to pass the serialized
IMA binary_runtime_measurements to the next kernel.
Link: http://lkml.kernel.org/r/1473938771-2782-6-git-send-email-zohar@xxxxxxxxxxxxxxxxxx
Signed-off-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Stewart Smith <stewart@xxxxxxxxxxxxxxxxxx>
Cc: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Cc: Eric Richter <erichte@xxxxxxxxxxxxxxxxxx>
Cc: Balbir Singh <bsingharora@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/ima.h | 12 +++
kernel/kexec_file.c | 4 +
security/integrity/ima/ima_kexec.c | 96 +++++++++++++++++++++++++++
3 files changed, 112 insertions(+)
diff -puN include/linux/ima.h~ima-on-soft-reboot-save-the-measurement-list include/linux/ima.h
--- a/include/linux/ima.h~ima-on-soft-reboot-save-the-measurement-list
+++ a/include/linux/ima.h
@@ -11,6 +11,7 @@
#define _LINUX_IMA_H
#include <linux/fs.h>
+#include <linux/kexec.h>
struct linux_binprm;
#ifdef CONFIG_IMA
@@ -23,6 +24,10 @@ extern int ima_post_read_file(struct fil
enum kernel_read_file_id id);
extern void ima_post_path_mknod(struct dentry *dentry);
+#ifdef CONFIG_IMA_KEXEC
+extern void ima_add_kexec_buffer(struct kimage *image);
+#endif
+
#else
static inline int ima_bprm_check(struct linux_binprm *bprm)
{
@@ -62,6 +67,13 @@ static inline void ima_post_path_mknod(s
#endif /* CONFIG_IMA */
+#ifndef CONFIG_IMA_KEXEC
+struct kimage;
+
+static inline void ima_add_kexec_buffer(struct kimage *image)
+{}
+#endif
+
#ifdef CONFIG_IMA_APPRAISE
extern void ima_inode_post_setattr(struct dentry *dentry);
extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
diff -puN kernel/kexec_file.c~ima-on-soft-reboot-save-the-measurement-list kernel/kexec_file.c
--- a/kernel/kexec_file.c~ima-on-soft-reboot-save-the-measurement-list
+++ a/kernel/kexec_file.c
@@ -20,6 +20,7 @@
#include <linux/list.h>
#include <linux/highmem.h>
#include <linux/fs.h>
+#include <linux/ima.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
#include <linux/syscalls.h>
@@ -204,6 +205,9 @@ kimage_file_prepare_segments(struct kima
return ret;
image->kernel_buf_len = size;
+ /* IMA needs to pass the measurement list to the next kernel. */
+ ima_add_kexec_buffer(image);
+
/* Call arch image probe handlers */
ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
image->kernel_buf_len);
diff -puN security/integrity/ima/ima_kexec.c~ima-on-soft-reboot-save-the-measurement-list security/integrity/ima/ima_kexec.c
--- a/security/integrity/ima/ima_kexec.c~ima-on-soft-reboot-save-the-measurement-list
+++ a/security/integrity/ima/ima_kexec.c
@@ -23,6 +23,11 @@
#include "ima.h"
+#ifdef CONFIG_IMA_KEXEC
+/* Physical address of the measurement buffer in the next kernel. */
+static unsigned long kexec_buffer_load_addr;
+static size_t kexec_segment_size;
+
static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
unsigned long segment_size)
{
@@ -75,6 +80,97 @@ out:
}
/*
+ * Called during kexec execute so that IMA can save the measurement list.
+ */
+static int ima_update_kexec_buffer(struct notifier_block *self,
+ unsigned long action, void *data)
+{
+ void *kexec_buffer = NULL;
+ size_t kexec_buffer_size;
+ int ret;
+
+ if (!kexec_in_progress)
+ return NOTIFY_OK;
+
+ kexec_buffer_size = ima_get_binary_runtime_size();
+ if (kexec_buffer_size > kexec_segment_size) {
+ pr_err("Binary measurement list grew too large.\n");
+ goto out;
+ }
+
+ ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer,
+ kexec_segment_size);
+ if (!kexec_buffer) {
+ pr_err("Not enough memory for the kexec measurement buffer.\n");
+ goto out;
+ }
+ ret = kexec_update_segment(kexec_buffer, kexec_buffer_size,
+ kexec_buffer_load_addr, kexec_segment_size);
+ if (ret)
+ pr_err("Error updating kexec buffer: %d\n", ret);
+out:
+ return NOTIFY_OK;
+}
+
+struct notifier_block update_buffer_nb = {
+ .notifier_call = ima_update_kexec_buffer,
+};
+
+/*
+ * Called during kexec_file_load so that IMA can add a segment to the kexec
+ * image for the measurement list for the next kernel.
+ */
+void ima_add_kexec_buffer(struct kimage *image)
+{
+ static int registered;
+ struct kexec_buf kbuf = { .image = image, .buf_align = PAGE_SIZE,
+ .buf_min = 0, .buf_max = ULONG_MAX,
+ .top_down = true };
+ unsigned long binary_runtime_size;
+ int ret;
+
+ if (!kexec_can_hand_over_buffer())
+ return;
+
+ /*
+ * Reserve at least an extra half page of memory for additional
+ * measurements between kexec load and execute.
+ */
+ binary_runtime_size = ima_get_binary_runtime_size();
+ if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE)
+ kexec_segment_size = ULONG_MAX;
+ else
+ kexec_segment_size = ALIGN(ima_get_binary_runtime_size() +
+ PAGE_SIZE / 2, PAGE_SIZE);
+ if ((kexec_segment_size == ULONG_MAX) ||
+ ((kexec_segment_size >> PAGE_SHIFT) > totalram_pages / 2)) {
+ pr_err("Binary measurement list too large.\n");
+ return;
+ }
+
+ /* Ask not to checksum the segment, we will update it later. */
+ kbuf.buffer = NULL;
+ kbuf.bufsz = 0;
+ kbuf.memsz = kexec_segment_size;
+ ret = kexec_add_handover_buffer(&kbuf);
+ if (ret) {
+ pr_err("Error passing over kexec measurement buffer.\n");
+ return;
+ }
+ kexec_buffer_load_addr = kbuf.mem;
+
+ pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n",
+ kexec_buffer_load_addr);
+
+ if (registered)
+ return;
+
+ register_reboot_notifier(&update_buffer_nb);
+ registered = 1;
+}
+#endif /* IMA_KEXEC */
+
+/*
* Restore the measurement list from the previous kernel.
*/
void ima_load_kexec_buffer(void)
_
Patches currently in -mm which might be from bauerman@xxxxxxxxxxxxxxxxxx are
kexec_file-allow-arch-specific-memory-walking-for-kexec_add_buffer.patch
kexec_file-change-kexec_add_buffer-to-take-kexec_buf-as-argument.patch
kexec_file-factor-out-kexec_locate_mem_hole-from-kexec_add_buffer.patch
powerpc-change-places-using-config_kexec-to-use-config_kexec_core-instead.patch
powerpc-factor-out-relocation-code-from-module_64c-to-elf_util_64c.patch
powerpc-generalize-elf64_apply_relocate_add.patch
powerpc-adapt-elf64_apply_relocate_add-for-kexec_file_load.patch
powerpc-add-functions-to-read-elf-files-of-any-endianness.patch
powerpc-implement-kexec_file_load.patch
powerpc-add-code-to-work-with-device-trees-in-kexec_file_load.patch
powerpc-add-support-for-loading-elf-kernels-with-kexec_file_load.patch
powerpc-add-purgatory-for-kexec_file_load-implementation.patch
powerpc-add-purgatory-for-kexec_file_load-implementation-fix.patch
powerpc-enable-config_kexec_file-in-powerpc-server-defconfigs.patch
kexec_file-include-the-purgatory-segment-in-the-kexec-image-checksum.patch
kexec_file-add-buffer-hand-over-support-for-the-next-kernel.patch
powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel.patch
kexec_file-add-mechanism-to-update-kexec-segments.patch
ima-on-soft-reboot-save-the-measurement-list.patch
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