Merge tag 'integrity-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity updates from Mimi Zohar:
 "Carrying the IMA measurement list across kexec is not a new feature,
  but is updated to address a couple of issues:

   - Carrying the IMA measurement list across kexec required knowing
     apriori all the file measurements between the "kexec load" and
     "kexec execute" in order to measure them before the "kexec load".
     Any delay between the "kexec load" and "kexec exec" exacerbated the
     problem.

   - Any file measurements post "kexec load" were not carried across
     kexec, resulting in the measurement list being out of sync with the
     TPM PCR.

  With these changes, the buffer for the IMA measurement list is still
  allocated at "kexec load", but copying the IMA measurement list is
  deferred to after quiescing the TPM.

  Two new kexec critical data records are defined"

* tag 'integrity-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: do not copy measurement list to kdump kernel
  ima: measure kexec load and exec events as critical data
  ima: make the kexec extra memory configurable
  ima: verify if the segment size has changed
  ima: kexec: move IMA log copy from kexec load to execute
  ima: kexec: define functions to copy IMA log at soft boot
  ima: kexec: skip IMA segment validation after kexec soft reboot
  kexec: define functions to map and unmap segments
  ima: define and call ima_alloc_kexec_file_buf()
  ima: rename variable the seq_file "file" to "ima_kexec_file"

2 files changed, 86 insertions, 1 deletions

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 3e62b944c883..9c59fa480b0b 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -877,6 +877,60 @@ int kimage_load_segment(struct kimage *image,
 	return result;
 }
 
+void *kimage_map_segment(struct kimage *image,
+			 unsigned long addr, unsigned long size)
+{
+	unsigned long src_page_addr, dest_page_addr = 0;
+	unsigned long eaddr = addr + size;
+	kimage_entry_t *ptr, entry;
+	struct page **src_pages;
+	unsigned int npages;
+	void *vaddr = NULL;
+	int i;
+
+	/*
+	 * Collect the source pages and map them in a contiguous VA range.
+	 */
+	npages = PFN_UP(eaddr) - PFN_DOWN(addr);
+	src_pages = kmalloc_array(npages, sizeof(*src_pages), GFP_KERNEL);
+	if (!src_pages) {
+		pr_err("Could not allocate ima pages array.\n");
+		return NULL;
+	}
+
+	i = 0;
+	for_each_kimage_entry(image, ptr, entry) {
+		if (entry & IND_DESTINATION) {
+			dest_page_addr = entry & PAGE_MASK;
+		} else if (entry & IND_SOURCE) {
+			if (dest_page_addr >= addr && dest_page_addr < eaddr) {
+				src_page_addr = entry & PAGE_MASK;
+				src_pages[i++] =
+					virt_to_page(__va(src_page_addr));
+				if (i == npages)
+					break;
+				dest_page_addr += PAGE_SIZE;
+			}
+		}
+	}
+
+	/* Sanity check. */
+	WARN_ON(i < npages);
+
+	vaddr = vmap(src_pages, npages, VM_MAP, PAGE_KERNEL);
+	kfree(src_pages);
+
+	if (!vaddr)
+		pr_err("Could not map ima buffer.\n");
+
+	return vaddr;
+}
+
+void kimage_unmap_segment(void *segment_buffer)
+{
+	vunmap(segment_buffer);
+}
+
 struct kexec_load_limit {
 	/* Mutex protects the limit count. */
 	struct mutex mutex;
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index fba686487e3b..0adb645072aa 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -38,6 +38,21 @@ void set_kexec_sig_enforced(void)
 }
 #endif
 
+#ifdef CONFIG_IMA_KEXEC
+static bool check_ima_segment_index(struct kimage *image, int i)
+{
+	if (image->is_ima_segment_index_set && i == image->ima_segment_index)
+		return true;
+	else
+		return false;
+}
+#else
+static bool check_ima_segment_index(struct kimage *image, int i)
+{
+	return false;
+}
+#endif
+
 static int kexec_calculate_store_digests(struct kimage *image);
 
 /* Maximum size in bytes for kernel/initrd files. */
@@ -186,6 +201,15 @@ kimage_validate_signature(struct kimage *image)
 }
 #endif
 
+static int kexec_post_load(struct kimage *image, unsigned long flags)
+{
+#ifdef CONFIG_IMA_KEXEC
+	if (!(flags & KEXEC_FILE_ON_CRASH))
+		ima_kexec_post_load(image);
+#endif
+	return machine_kexec_post_load(image);
+}
+
 /*
  * In file mode list of segments is prepared by kernel. Copy relevant
  * data from user space, do error checking, prepare segment list
@@ -413,7 +437,7 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
 
 	kimage_terminate(image);
 
-	ret = machine_kexec_post_load(image);
+	ret = kexec_post_load(image, flags);
 	if (ret)
 		goto out;
 
@@ -776,6 +800,13 @@ static int kexec_calculate_store_digests(struct kimage *image)
 		if (ksegment->kbuf == pi->purgatory_buf)
 			continue;
 
+		/*
+		 * Skip the segment if ima_segment_index is set and matches
+		 * the current index
+		 */
+		if (check_ima_segment_index(image, i))
+			continue;
+
 		ret = crypto_shash_update(desc, ksegment->kbuf,
 					  ksegment->bufsz);
 		if (ret)