[PATCH 5.10 08/54] io_uring: if we see flush on exit, cancel related tasks

Greg Kroah-Hartman
2021-02-11T15:44:02Z

From: Jens Axboe <axboe@kernel.dk>

[ Upstream commit 84965ff8a84f0368b154c9b367b62e59c1193f30 ]

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>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/io_uring.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1014,8 +1014,12 @@ static bool io_match_task(struct io_kioc
{
struct io_kiocb *link;

- 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;
if (__io_match_files(head, files))
@@ -8844,6 +8848,9 @@ static int io_uring_flush(struct file *f
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;