[PATCH 5.10 517/717] io_uring: fix 0-iov read buffer select

From: Pavel Begunkov asml.silence@gmail.com

commit dd20166236953c8cd14f4c668bf972af32f0c6be upstream.

Doing vectored buf-select read with 0 iovec passed is meaningless and utterly broken, forbid it.

Cc: stable@vger.kernel.org # 5.7+ Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- fs/io_uring.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3048,9 +3048,7 @@ static ssize_t io_iov_buffer_select(stru iov[0].iov_len = kbuf->len; return 0; } - if (!req->rw.len) - return 0; - else if (req->rw.len > 1) + if (req->rw.len != 1) return -EINVAL;

#ifdef CONFIG_COMPAT