@@ -358,6 +358,9 @@ struct kimage {
phys_addr_t ima_buffer_addr;
size_t ima_buffer_size;
+
+ unsigned long ima_segment_index;
+ bool is_ima_segment_index_set;
#endif
/* Core ELF header buffer */
@@ -750,6 +750,14 @@ 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 (image->is_ima_segment_index_set &&
+ i == image->ima_segment_index)
+ continue;
+
ret = crypto_shash_update(desc, ksegment->kbuf,
ksegment->bufsz);
if (ret)
@@ -161,6 +161,7 @@ void ima_add_kexec_buffer(struct kimage *image)
kbuf.buffer = kexec_buffer;
kbuf.bufsz = kexec_buffer_size;
kbuf.memsz = kexec_segment_size;
+ image->is_ima_segment_index_set = false;
ret = kexec_add_buffer(&kbuf);
if (ret) {
pr_err("Error passing over kexec measurement buffer.\n");
@@ -171,6 +172,8 @@ void ima_add_kexec_buffer(struct kimage *image)
image->ima_buffer_addr = kbuf.mem;
image->ima_buffer_size = kexec_segment_size;
image->ima_buffer = kexec_buffer;
+ image->ima_segment_index = image->nr_segments - 1;
+ image->is_ima_segment_index_set = true;
/*
* kexec owns kexec_buffer after kexec_add_buffer() is called
kexec_calculate_store_digests() calculates and stores the digest of the segment at kexec_file_load syscall where the IMA segment is also allocated. With this series, the IMA segment will be updated with the measurement log at kexec soft reboot. Therefore, it may fail digest verification in verify_sha256_digest() after kexec soft reboot into the new Kernel. Therefore, the digest calculation, storage, and verification of the IMA segment needs to be skipped. Skip IMA segment from calculating and storing digest in function kexec_calculate_store_digests() so that it is not added to the 'purgatory_sha_regions'. Since verify_sha256_digest() only verifies 'purgatory_sha_regions', no change is needed in verify_sha256_digest() in this context. With this change, the IMA segment is not included in the digest calculation, storage, and verification. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> --- include/linux/kexec.h | 3 +++ kernel/kexec_file.c | 8 ++++++++ security/integrity/ima/ima_kexec.c | 3 +++ 3 files changed, 14 insertions(+)