Validate size of EFI GUID partition entries.

commit fa039d5f6b126fbd65eefa05db2f67e44df8f121 upstream.

Otherwise corrupted EFI partition tables can cause total confusion.

Signed-off-by: Timo Warns <warns@pre-sense.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/partitions/efi.c b/fs/partitions/efi.c
index 49cfd5f5423894df4c2f52ac48bac1f82a9b43a3..2aac7764b7e5146bbac9ea5dadc23c029ae4dd78 100644 (file)
--- a/fs/partitions/efi.c
+++ b/fs/partitions/efi.c
@@ -349,6 +349,12 @@ is_gpt_valid(struct block_device *bdev, u64 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");
+               goto fail;
+       }
+
        if (!(*ptes = alloc_read_gpt_entries(bdev, *gpt)))
                goto fail;