When reading a directory, EFI_BUFFER_TOO_SMALL should be returned when the supplied buffer is too small, so a use-case is to call efi_file_read with *buffer_size=0 and buffer=NULL to obtain the needed size before doing the actual read.
So move the buffer!=NULL check to after the buffer size has been checked.
This fix allows the Redhat shim fallback to run and e.g. Fedora 32 now boots out of the box.
Signed-off-by: Stefan Sørensen stefan.sorensen@spectralink.com --- lib/efi_loader/efi_file.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c index 19afa69f53..44fafae058 100644 --- a/lib/efi_loader/efi_file.c +++ b/lib/efi_loader/efi_file.c @@ -349,6 +349,11 @@ static efi_status_t file_read(struct file_handle *fh, u64 *buffer_size, efi_status_t ret; loff_t file_size;
+ if (!buffer) { + ret = EFI_INVALID_PARAMETER; + return ret; + } + ret = efi_get_file_size(fh, &file_size); if (ret != EFI_SUCCESS) return ret; @@ -414,6 +419,8 @@ static efi_status_t dir_read(struct file_handle *fh, u64 *buffer_size, fh->dent = dent; return EFI_BUFFER_TOO_SMALL; } + if (!buffer) + return EFI_INVALID_PARAMETER; fh->dent = NULL;
*buffer_size = required_size; @@ -443,7 +450,7 @@ static efi_status_t EFIAPI efi_file_read(struct efi_file_handle *file,
EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
- if (!buffer_size || !buffer) { + if (!buffer_size) { ret = EFI_INVALID_PARAMETER; goto error; }