efi_loader: parameter checks BLOCK_IO_PROTOCOL

Check parameters of ReadBlocks() and WriteBlocks().

If the buffer size is not a multiple of the block size, we have to return
EFI_BAD_BUFFER_SIZE.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index 7a6b06821a477895354807722c6d0dd36c046c04..0bf436ac666e2c5ccc928eaddafe6751c15d5659 100644 (file)
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -74,7 +74,7 @@ static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
 
        /* We only support full block access */
        if (buffer_size & (blksz - 1))
-               return EFI_DEVICE_ERROR;
+               return EFI_BAD_BUFFER_SIZE;
 
        if (direction == EFI_DISK_READ)
                n = blk_dread(desc, lba, blocks, buffer);
@@ -99,6 +99,20 @@ static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
        void *real_buffer = buffer;
        efi_status_t r;
 
+       if (!this)
+               return EFI_INVALID_PARAMETER;
+       /* TODO: check for media changes */
+       if (media_id != this->media->media_id)
+               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))
+               return EFI_INVALID_PARAMETER;
+       if (lba * this->media->block_size + buffer_size >
+           this->media->last_block * this->media->block_size)
+               return EFI_INVALID_PARAMETER;
+
 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
        if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
                r = efi_disk_read_blocks(this, media_id, lba,
@@ -134,6 +148,22 @@ static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
        void *real_buffer = buffer;
        efi_status_t r;
 
+       if (!this)
+               return EFI_INVALID_PARAMETER;
+       if (this->media->read_only)
+               return EFI_WRITE_PROTECTED;
+       /* TODO: check for media changes */
+       if (media_id != this->media->media_id)
+               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))
+               return EFI_INVALID_PARAMETER;
+       if (lba * this->media->block_size + buffer_size >
+           this->media->last_block * this->media->block_size)
+               return EFI_INVALID_PARAMETER;
+
 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
        if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
                r = efi_disk_write_blocks(this, media_id, lba,
@@ -288,6 +318,11 @@ static efi_status_t efi_disk_add_dev(
        /* Fill in EFI IO Media info (for read/write callbacks) */
        diskobj->media.removable_media = desc->removable;
        diskobj->media.media_present = 1;
+       /*
+        * MediaID is just an arbitrary counter.
+        * We have to change it if the medium is removed or changed.
+        */
+       diskobj->media.media_id = 1;
        diskobj->media.block_size = desc->blksz;
        diskobj->media.io_align = desc->blksz;
        diskobj->media.last_block = desc->lba - offset;