bdrv_pad_request() relies on requests' lengths not to exceed SIZE_MAX,
which bdrv_check_qiov_request() does not guarantee.
bdrv_check_request32() however will guarantee this, and both of
bdrv_pad_request()'s callers (bdrv_co_preadv_part() and
bdrv_co_pwritev_part()) already run it before calling
bdrv_pad_request(). Therefore, bdrv_pad_request() can safely call
bdrv_check_request32() without expecting error, too.
There is one difference between bdrv_check_qiov_request() and
bdrv_check_request32(): The former takes an errp, the latter does not,
so we can no longer just pass &error_abort. Instead, we need to check
the returned value. While we do expect success (because the callers
have already run this function), an assert(ret == 0) is not much simpler
than just to return an error if it occurs, so let us handle errors by
returning them up the stack now.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Fixes: 18743311b829cafc1737a5f20bc3248d5f91ee2a
("block: Collapse padded I/O vecs exceeding IOV_MAX")
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
---
block/io.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)