ntdll: Fix length calculation of generated SMBIOS tables.

An extra byte for a null-terminator was added for every string, but not used when the string was empty. This resulted in extra bytes at the end of the buffer, causing parse errors in dmidecode. Signed-off-by: Brendan Shanks <bshanks@codeweavers.com> Signed-off-by: Alexandre Julliard <julliard@winehq.org>

ntdll: Fix length calculation of generated SMBIOS tables.
b11afa17 · Brendan Shanks · Alexandre Julliard · 217dfead · b11afa17
Commit b11afa17 authored May 13, 2020 by Brendan Shanks Committed by Alexandre Julliard May 14, 2020
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nt.c dlls/ntdll/nt.c +8 -6

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--- a/dlls/ntdll/nt.c
+++ b/dlls/ntdll/nt.c
@@ -2191,19 +2191,21 @@ static NTSTATUS get_firmware_info(SYSTEM_FIRMWARE_TABLE_INFORMATION *sfti, ULONG

            *required_len = sizeof(struct smbios_prologue);

+#define L(l) (l + (l ? 1 : 0))
            *required_len += sizeof(struct smbios_bios);
-            *required_len += max(bios_vendor_len + bios_version_len + bios_date_len + 4, 2);
+            *required_len += max(L(bios_vendor_len) + L(bios_version_len) + L(bios_date_len) + 1, 2);

            *required_len += sizeof(struct smbios_system);
-            *required_len += max(system_vendor_len + system_product_len + system_version_len +
-                                 system_serial_len + system_sku_len + system_family_len + 7, 2);
+            *required_len += max(L(system_vendor_len) + L(system_product_len) + L(system_version_len) +
+                                 L(system_serial_len) + L(system_sku_len) + L(system_family_len) + 1, 2);

            *required_len += sizeof(struct smbios_board);
-            *required_len += max(board_vendor_len + board_product_len + board_version_len + board_serial_len + 5, 2);
+            *required_len += max(L(board_vendor_len) + L(board_product_len) + L(board_version_len) + L(board_serial_len) + 1, 2);

            *required_len += sizeof(struct smbios_chassis);
-            *required_len += max(chassis_vendor_len + chassis_version_len + chassis_serial_len +
-                                 chassis_asset_tag_len + 5, 2);
+            *required_len += max(L(chassis_vendor_len) + L(chassis_version_len) + L(chassis_serial_len) +
+                                 L(chassis_asset_tag_len) + 1, 2);
+#undef L

            sfti->TableBufferLength = *required_len;