From: Jens Axboe axboe@kernel.dk
commit 78a780602075d8b00c98070fa26e389b3b3efa72 upstream.
If we successfully cancel a work item but that work item needs to be processed through task_work, then we can be sleeping uninterruptibly in io_uring_cancel_generic() and never process it. Hence we don't make forward progress and we end up with an uninterruptible sleep warning.
While in there, correct a comment that should be IFF, not IIF.
Reported-and-tested-by: syzbot+21e6887c0be14181206d@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/io_uring.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -9775,7 +9775,7 @@ static void io_uring_drop_tctx_refs(stru
/* * Find any io_uring ctx that this task has registered or done IO on, and cancel - * requests. @sqd should be not-null IIF it's an SQPOLL thread cancellation. + * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation. */ static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd) { @@ -9816,8 +9816,10 @@ static void io_uring_cancel_generic(bool cancel_all); }
- prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE); + prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE); + io_run_task_work(); io_uring_drop_tctx_refs(current); + /* * If we've seen completions, retry without waiting. This * avoids a race where a completion comes in before we did