2012-10-25 11:15:39

by Davidlohr Bueso

[permalink] [raw]
Subject: [PATCH RESEND 1/3] 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 <[email protected]>
---
block/partitions/efi.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index 6296b40..7795bb4 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -344,6 +344,12 @@ static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
* within the disk.
*/
lastlba = last_lba(state->bdev);
+ 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;
+ }
if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
(unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
--
1.7.9.5