From: Davidlohr Bueso <davidlohr@hp.com>
Date: Wed, 11 Sep 2013 21:24:56 +0000 (-0700)
Subject: partitions/efi: check pmbr record's starting lba
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=33afd7a7df1a1f82675857a75572cdf4a8599e9f;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

partitions/efi: check pmbr record's starting lba

Per the UEFI Specs 2.4, June 2013, the starting lba of the partition that
has the EFI GPT (0xEE) must be set to 0x00000001 - this is obviously the
LBA of the GPT Partition Header.

[akpm@linux-foundation.org: coding-style fixes]
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 bd8fb22b2109..7a2b74f0d06f 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -151,10 +151,19 @@ static u64 last_lba(struct block_device *bdev)
 
 static inline int pmbr_part_valid(gpt_mbr_record *part)
 {
-	if (part->os_type == EFI_PMBR_OSTYPE_EFI_GPT &&
-	    le32_to_cpu(part->start_sector) == 1UL)
-		return 1;
-        return 0;
+	if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT)
+		goto invalid;
+
+	/* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */
+	if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA)
+		goto invalid;
+
+	if (le32_to_cpu(part->start_sector) != 1UL)
+		goto invalid;
+
+	return 1;
+invalid:
+	return 0;
 }
 
 /**