partitions/efi: compare first and last usable LBAs
When verifying GPT header integrity, make sure that first usable LBA is
smaller than last usable LBA.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Karel Zak <kzak@redhat.com>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index b028af6..de9f9bf 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -410,7 +410,12 @@
(unsigned long long)lastlba);
goto fail;
}
-
+ if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) {
+ pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
+ (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
+ (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba));
+ goto fail;
+ }
/* Check that sizeof_partition_entry has the correct value */
if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
pr_debug("GUID Partitition Entry Size check failed.\n");