From: Jens Axboe axboe@kernel.dk
commit 03b3d6be73e81ddb7c2930d942cdd17f4cfd5ba5 upstream.
It's possible for a file type to support uring commands, but not pollable ones. Hence before issuing one of those, we should check that it is supported and error out upfront if it isn't.
Cc: stable@vger.kernel.org Fixes: 5756a3a7e713 ("io_uring: add iopoll infrastructure for io_uring_cmd") Link: https://github.com/axboe/liburing/issues/816 Reviewed-by: Kanchan Joshi joshi.k@samsung.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/uring_cmd.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -108,7 +108,7 @@ int io_uring_cmd(struct io_kiocb *req, u struct file *file = req->file; int ret;
- if (!req->file->f_op->uring_cmd) + if (!file->f_op->uring_cmd) return -EOPNOTSUPP;
ret = security_uring_cmd(ioucmd); @@ -120,6 +120,8 @@ int io_uring_cmd(struct io_kiocb *req, u if (ctx->flags & IORING_SETUP_CQE32) issue_flags |= IO_URING_F_CQE32; if (ctx->flags & IORING_SETUP_IOPOLL) { + if (!file->f_op->uring_cmd_iopoll) + return -EOPNOTSUPP; issue_flags |= IO_URING_F_IOPOLL; req->iopoll_completed = 0; WRITE_ONCE(ioucmd->cookie, NULL);