io_uring/rw: ensure io->bytes_done is always initialized

If IOSQE_ASYNC is set and we fail importing an iovec for a readv or
writev request, then we leave ->bytes_done uninitialized and hence the
eventual failure CQE posted can potentially have a random res value
rather than the expected -EINVAL.

Setup ->bytes_done before potentially failing, so we have a consistent
value if we fail the request early.

Cc: stable@vger.kernel.org
Reported-by: xingwei lee <xrivendell7@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2023-12-21 08:49:18 -07:00
parent 6e5e6d2749
commit 0a535eddbe

View File

@ -589,15 +589,19 @@ static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
struct iovec *iov;
int ret;
iorw->bytes_done = 0;
iorw->free_iovec = NULL;
/* submission path, ->uring_lock should already be taken */
ret = io_import_iovec(rw, req, &iov, &iorw->s, 0);
if (unlikely(ret < 0))
return ret;
iorw->bytes_done = 0;
iorw->free_iovec = iov;
if (iov)
if (iov) {
iorw->free_iovec = iov;
req->flags |= REQ_F_NEED_CLEANUP;
}
return 0;
}