From: Jens Axboe <axboe@kernel.dk>
Date: Sat, 23 Jan 2021 22:51:11 +0000 (-0700)
Subject: io_uring: if we see flush on exit, cancel related tasks
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=84965ff8a84f0;p=linux.git

io_uring: if we see flush on exit, cancel related tasks

Ensure we match tasks that belong to a dead or dying task as well, as we
need to reap those in addition to those belonging to the exiting task.

Cc: stable@vger.kernel.org # 5.9+
Reported-by: Josef Grieb <josef.grieb@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index c07913ec0ccac..695fe00bafdcd 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1069,8 +1069,12 @@ static bool io_match_task(struct io_kiocb *head,
 {
 	struct io_kiocb *req;
 
-	if (task && head->task != task)
+	if (task && head->task != task) {
+		/* in terms of cancelation, always match if req task is dead */
+		if (head->task->flags & PF_EXITING)
+			return true;
 		return false;
+	}
 	if (!files)
 		return true;
 
@@ -9136,6 +9140,9 @@ static int io_uring_flush(struct file *file, void *data)
 	struct io_uring_task *tctx = current->io_uring;
 	struct io_ring_ctx *ctx = file->private_data;
 
+	if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
+		io_uring_cancel_task_requests(ctx, NULL);
+
 	if (!tctx)
 		return 0;