diff mbox series

[v2,1/2] tcgbios: Fix endianess of NumberOfPartitions

Message ID 20250405021507.2707113-2-stefanb@linux.ibm.com
State New
Headers show
Series tcgbios: Fix 2 issues related to handling of GPT table | expand

Commit Message

Stefan Berger April 5, 2025, 2:15 a.m. UTC 
Write the 64bit integer 'NumberOfPartitions' in little endian format into
the uefi_gpt_data so that they end up in little endian format in the
measurement log.

Fixes: 16a1867425ee ("tcgbios: Measure the GPT table")
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
 lib/libtpm/tcgbios.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/lib/libtpm/tcgbios.c b/lib/libtpm/tcgbios.c
index 03443f9..5e657bd 100644
--- a/lib/libtpm/tcgbios.c
+++ b/lib/libtpm/tcgbios.c
@@ -1092,7 +1092,7 @@  void tpm_gpt_set_lba1(const uint8_t *addr, uint32_t length)
 
 	memcpy(&uefi_gpt_data->EfiPartitionHeader,
 	       addr, MIN(sizeof(uefi_gpt_data->EfiPartitionHeader), length));
-	uefi_gpt_data->NumberOfPartitions = 0;
+	uefi_gpt_data->NumberOfPartitions = cpu_to_le64(0);
 }
 
 /*
@@ -1104,6 +1104,7 @@  void tpm_gpt_add_entry(const uint8_t *addr, uint32_t length)
 	size_t sz;
 	UEFI_PARTITION_ENTRY *upe = (void *)addr;
 	void *tmp;
+	uint64_t numberOfPartitions;
 
 	if (!tpm_is_working() ||
 	    !uefi_gpt_data ||
@@ -1111,8 +1112,9 @@  void tpm_gpt_add_entry(const uint8_t *addr, uint32_t length)
 	    !memcmp(upe->partTypeGuid, ZeroGuid, sizeof(ZeroGuid)))
 		return;
 
+	numberOfPartitions = le64_to_cpu(uefi_gpt_data->NumberOfPartitions);
 	sz = offset_of(UEFI_GPT_DATA, Partitions) +
-	       (uefi_gpt_data->NumberOfPartitions + 1)
+	       (numberOfPartitions + 1)
 	       * sizeof(UEFI_PARTITION_ENTRY);
 	if (sz > uefi_gpt_data_size) {
 		tmp = SLOF_alloc_mem(sz);
@@ -1125,10 +1127,12 @@  void tpm_gpt_add_entry(const uint8_t *addr, uint32_t length)
 		uefi_gpt_data_size = sz;
 	}
 
-	memcpy(&uefi_gpt_data->Partitions[uefi_gpt_data->NumberOfPartitions],
+	memcpy(&uefi_gpt_data->Partitions[numberOfPartitions],
 	       addr,
 	       sizeof(UEFI_PARTITION_ENTRY));
-	uefi_gpt_data->NumberOfPartitions++;
+
+	numberOfPartitions++;
+	uefi_gpt_data->NumberOfPartitions = cpu_to_le64(numberOfPartitions);
 
 	return;
 
@@ -1150,7 +1154,8 @@  uint32_t tpm_measure_gpt(void)
 		return TCGBIOS_GENERAL_ERROR;
 
 	sz = offset_of(UEFI_GPT_DATA, Partitions) +
-	     uefi_gpt_data->NumberOfPartitions * sizeof(UEFI_PARTITION_ENTRY);
+	       le64_to_cpu(uefi_gpt_data->NumberOfPartitions)
+	       * sizeof(UEFI_PARTITION_ENTRY);
 
 	return tpm_add_measurement_to_log(5, EV_EFI_GPT_EVENT,
 					  (const char *)uefi_gpt_data, sz,