Brendan Shanks : ntdll: Fix length calculation of generated SMBIOS tables.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: b11afa1725cc059e89dd88c00096cc31778d326f
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=b11afa1725cc059e89dd88c00...

Author: Brendan Shanks <bshanks(a)codeweavers.com>
Date:   Wed May 13 14:07:30 2020 -0700

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(a)codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard(a)winehq.org>

---

 dlls/ntdll/nt.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/dlls/ntdll/nt.c b/dlls/ntdll/nt.c
index 6c95517e79..4dced31641 100644
--- 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;