APPEND_WRITE with data length zero is allowable according to the UEFI specification.

The EDK2 interpretation of no access attributes is attributes = 0. As the UEFI specification is vague in this respect let's stick to EDK2 here.

Fixes: commit 6d2f27c5fd60 ("efi_loader: variable: support APPEND_WRITE") Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de --- lib/efi_loader/efi_variable.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c index 22ad271bd8..4c554c546b 100644 --- a/lib/efi_loader/efi_variable.c +++ b/lib/efi_loader/efi_variable.c @@ -443,8 +443,6 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, if (ret) goto out;

-#define ACCESS_ATTR (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS) - old_val = env_get(native_name); if (old_val) { old_val = parse_attr(old_val, &attr); @@ -455,7 +453,9 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, goto out; }

- if ((data_size == 0) || !(attributes & ACCESS_ATTR)) { + if ((data_size == 0 && + !(attributes & EFI_VARIABLE_APPEND_WRITE)) || + !attributes) { /* delete the variable: */ env_set(native_name, NULL); ret = EFI_SUCCESS; @@ -478,8 +478,9 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, old_size = 0; } } else { - if ((data_size == 0) || !(attributes & ACCESS_ATTR) || - (attributes & EFI_VARIABLE_APPEND_WRITE)) { + if ((data_size == 0 && + !(attributes & EFI_VARIABLE_APPEND_WRITE)) || + !attributes) { /* delete, but nothing to do */ ret = EFI_NOT_FOUND; goto out; -- 2.23.0