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From:   Nikolai Merinov <n.merinov@inango-systems.com>
To:     Davidlohr Bueso <dave@stgolabs.net>, Jens Axboe <axboe@kernel.dk>,
        linux-efi@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Nikolai Merinov <n.merinov@inango-systems.com>
Subject: [PATCH v2] partitions/efi: Fix partition name parsing in GUID partition entry
Date:   Tue, 24 Dec 2019 14:21:19 +0500
Message-Id: <20191224092119.4581-1-n.merinov@inango-systems.com>
In-Reply-To: <20181124162123.21300-1-n.merinov@inango-systems.com>
References: <20181124162123.21300-1-n.merinov@inango-systems.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

GUID partition entry defined to have a partition name as 36 UTF-16LE
code units. This means that on big-endian platforms ASCII symbols
would be read with 0xXX00 efi_char16_t character code. In order to
correctly extract ASCII characters from a partition name field we
should be converted from 16LE to CPU architecture.

The problem exists on all big endian platforms.

Signed-off-by: Nikolai Merinov <n.merinov@inango-systems.com>

diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index db2fef7dfc47..51287a8a3bea 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -715,7 +715,7 @@ int efi_partition(struct parsed_partitions *state)
 				ARRAY_SIZE(ptes[i].partition_name));
 		info->volname[label_max] = 0;
 		while (label_count < label_max) {
-			u8 c = ptes[i].partition_name[label_count] & 0xff;
+			u8 c = le16_to_cpu(ptes[i].partition_name[label_count]) & 0xff;
 			if (c && !isprint(c))
 				c = '!';
 			info->volname[label_count] = c;
diff --git a/block/partitions/efi.h b/block/partitions/efi.h
index 3e8576157575..0b6d5b7be111 100644
--- a/block/partitions/efi.h
+++ b/block/partitions/efi.h
@@ -88,7 +88,7 @@ typedef struct _gpt_entry {
 	__le64 starting_lba;
 	__le64 ending_lba;
 	gpt_entry_attributes attributes;
-	efi_char16_t partition_name[72 / sizeof (efi_char16_t)];
+	__le16 partition_name[72 / sizeof (__le16)];
 } __packed gpt_entry;
 
 typedef struct _gpt_mbr_record {
-- 
2.17.1