From 688e88256f4137b23522b45727a8207983be90a1 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 23 Jan 2021 19:33:11 +0100 Subject: [PATCH] efi_loader: correct block IO alignment check If the field Media->IoAlign of the EFI block IO protocol is zero, no alignment is required. Our code required 4 GiB alignment in this case. Don't check buffer alignment if Media->IoAlign == 0. Fixes: f59f0825e8b9 ("efi_loader: parameter checks BLOCK_IO_PROTOCOL") Signed-off-by: Heinrich Schuchardt --- lib/efi_loader/efi_disk.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c index c0804effde..d0aad0252a 100644 --- a/lib/efi_loader/efi_disk.c +++ b/lib/efi_loader/efi_disk.c @@ -142,8 +142,9 @@ static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this, return EFI_MEDIA_CHANGED; if (!this->media->media_present) return EFI_NO_MEDIA; - /* media->io_align is a power of 2 */ - if ((uintptr_t)buffer & (this->media->io_align - 1)) + /* media->io_align is a power of 2 or 0 */ + if (this->media->io_align && + (uintptr_t)buffer & (this->media->io_align - 1)) return EFI_INVALID_PARAMETER; if (lba * this->media->block_size + buffer_size > this->media->last_block * this->media->block_size) @@ -209,8 +210,9 @@ static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this, return EFI_MEDIA_CHANGED; if (!this->media->media_present) return EFI_NO_MEDIA; - /* media->io_align is a power of 2 */ - if ((uintptr_t)buffer & (this->media->io_align - 1)) + /* media->io_align is a power of 2 or 0 */ + if (this->media->io_align && + (uintptr_t)buffer & (this->media->io_align - 1)) return EFI_INVALID_PARAMETER; if (lba * this->media->block_size + buffer_size > this->media->last_block * this->media->block_size) -- 2.39.5