From 07463d7da99985d8254f6e5c66cd9843037a9bbd Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 12 Oct 2020 11:53:29 -0600 Subject: io_uring: don't run task work on an exiting task commit 6200b0ae4ea28a4bfd8eb434e33e6201b7a6a282 upstream. This isn't safe, and isn't needed either. We are guaranteed that any work we queue is on a live task (and will be run), or it goes to our backup io-wq threads if the task is exiting. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index d2bb2ae9551f..b706a4538a7f 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1762,6 +1762,12 @@ static int io_put_kbuf(struct io_kiocb *req) static inline bool io_run_task_work(void) { + /* + * Not safe to run on exiting task, and the task_work handling will + * not add work to such a task. + */ + if (unlikely(current->flags & PF_EXITING)) + return false; if (current->task_works) { __set_current_state(TASK_RUNNING); task_work_run(); @@ -7791,6 +7797,8 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, io_put_req(cancel_req); } + /* cancellations _may_ trigger task work */ + io_run_task_work(); schedule(); finish_wait(&ctx->inflight_wait, &wait); } -- cgit v1.2.3