efi/x86: Fix the deletion of variables in mixed mode

[ Upstream commit a4b81ccfd4caba017d2b84720b6de4edd16911a0 ]

efi_thunk_set_variable() treated the NULL "data" pointer as an invalid
parameter, and this broke the deletion of variables in mixed mode.
This commit fixes the check of data so that the userspace program can
delete a variable in mixed mode.

Fixes: 8319e9d5ad98ffcc ("efi/x86: Handle by-ref arguments covering multiple pages in mixed mode")
Signed-off-by: Gary Lin <glin@suse.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200408081606.1504-1-glin@suse.com
Link: https://lore.kernel.org/r/20200409130434.6736-9-ardb@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index d19a2edd63cb224e33408d094d0df58f6ed3508c..a47294063882046ee893ebf157c461c5475ad3d9 100644 (file)
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -641,7 +641,7 @@ efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
        phys_vendor = virt_to_phys_or_null(vnd);
        phys_data = virt_to_phys_or_null_size(data, data_size);
 
-       if (!phys_name || !phys_data)
+       if (!phys_name || (data && !phys_data))
                status = EFI_INVALID_PARAMETER;
        else
                status = efi_thunk(set_variable, phys_name, phys_vendor,
@@ -672,7 +672,7 @@ efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
        phys_vendor = virt_to_phys_or_null(vnd);
        phys_data = virt_to_phys_or_null_size(data, data_size);
 
-       if (!phys_name || !phys_data)
+       if (!phys_name || (data && !phys_data))
                status = EFI_INVALID_PARAMETER;
        else
                status = efi_thunk(set_variable, phys_name, phys_vendor,