This is a note to let you know that I've just added the patch titled io_uring/uring_cmd: ensure that device supports IOPOLL to the 6.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-uring_cmd-ensure-that-device-supports-iopoll.patch and it can be found in the queue-6.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 03b3d6be73e81ddb7c2930d942cdd17f4cfd5ba5 Mon Sep 17 00:00:00 2001 From: Jens Axboe <axboe@xxxxxxxxx> Date: Wed, 8 Mar 2023 09:26:13 -0700 Subject: io_uring/uring_cmd: ensure that device supports IOPOLL From: Jens Axboe <axboe@xxxxxxxxx> 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@xxxxxxxxxxxxxxx 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@xxxxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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); Patches currently in stable-queue which might be from axboe@xxxxxxxxx are queue-6.2/io_uring-uring_cmd-ensure-that-device-supports-iopoll.patch