Validate size of EFI GUID partition entries.

Otherwise corrupted EFI partition tables can cause total confusion.

Signed-off-by: Timo Warns <warns@pre-sense.de>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/partitions/efi.c b/fs/partitions/efi.c
index ac0ccb5026a2..19d6750d1d6c 100644
--- a/fs/partitions/efi.c
+++ b/fs/partitions/efi.c
@@ -348,6 +348,12 @@ static int is_gpt_valid(struct parsed_partitions *state, 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(state, *gpt)))
                 goto fail;