id = 1460
title = "block_load fails if last block is included in snapshot and block device isn't multiple of BLK_MIG_BLOCK_SIZE"
state = "closed"
created_at = "2023-01-23T23:54:50.430Z"
closed_at = "2024-05-10T13:19:38.529Z"
labels = ["Migration"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/1460"
host-os = "Linux"
host-arch = "N/A"
qemu-version = "7.x"
guest-os = "n/a"
guest-arch = "n/a"
description = """The `block_load` function in `migration/block.c` has a bug where `blk_pwrite` or `blk_pwrite_zeroes` always write `cluster_size` bytes. If the underlying device is not a multiple of `BLK_MIG_BLOCK_SIZE`, the write will fail with -EIO when trying to write past the end of the device, as `blk_check_byte_request` checks the length of the device.

This can be fixed by ensuring that `cur_addr` + write length passed to `blk_pwrite`/`blk_pwrite_zeroes` never exceeds the total length of the block device."""
reproduce = "n/a"
additional = "n/a"